JP2023542323A - Display of 3D objects - Google Patents

Abstract

Methods, devices, and systems are provided for displaying three-dimensional objects by individually diffracting light of different colors. In one aspect, an optical diffractive device includes a first diffractive component and a second diffractive component and a color selective polarizer therebetween. The first optical diffractive component is configured to diffract light of a first color in a first polarization state incident at a first angle of incidence with a first diffraction efficiency at a first diffraction angle; The second color light in the polarization state is diffracted with a diffraction efficiency substantially lower than the first diffraction efficiency. The polarizer is configured to rotate a second polarization state of the second color of light to a first polarization state. The second diffractive component is configured to diffract light of a second color in the first polarization state at a second diffraction angle that is substantially the same as the first diffraction angle and with a second diffraction efficiency. has been done.
[Selection diagram] Figure 10B

Description

INCORPORATION BY REFERENCE This application is filed under 35 U.S.C. 119, entitled "DISPLAYING THREE-DIMENSIONAL OBJECTS," filed on September 17, 2020. S. S. N. No. 63/079,707, and U.S. Pat. S. S. N. No. 63/149,964, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD This disclosure relates to three-dimensional (3D) displays, and more particularly to 3D displays with object reconstruction.

Advances in traditional two-dimensional (2D) projection and 3D rendering have enabled many to mix head and eye tracking with traditional display devices for virtual reality (VR), augmented reality (AR), and mixed reality (MR). A new approach to 3D display has emerged, including hybrid technology. These techniques, in combination with tracking and measurement-based calculations, attempt to recreate the experience of holographic images and simulate the stereo or intraocular light field that may be represented by a real hologram.

This disclosure describes methods, apparatus, devices, and systems for reconstructing objects (e.g., 2D or 3D), particularly with display zero-order light suppression. The present disclosure efficiently suppresses display zero-order light (e.g., reflected, diffracted, or transmitted) from a display in a reconstructed holographic scene (or holographic content) to improve the effects of the holographic scene. , and thus provide techniques that can improve the performance of display systems. As an example, when light illuminates the display for holographic reconstruction, a portion of the light is modulated by the hologram and impinges on the display element forming the desired holographic scene and is diffracted by the display element. Another portion of the light enters gaps between display elements on the display and is reflected at the gaps. The other reflected portion of the light can be considered as display zero-order light of at least a portion (eg, the dominant order) that may be undesirably presented to the holographic scene. The display zero order light may also include any other unwanted light from the display, such as light diffracted at a gap, reflected light from a display element, or reflected light from a display cover on the display. Embodiments of the present disclosure can suppress such display zero order light.

In some implementations, the hologram is configured such that a first portion of the light that is illuminated onto the display element of the display is diffracted by the display element modulated by the hologram to generate zero-order light, including reflected light from the display. is configured to have at least one characteristic different from the The display zero order light may include a second portion of the light that is illuminated onto the gap between the display elements and reflected at the gap without modulation of the hologram. The technique utilizes the difference between the diffracted first portion of the light and the display zero-order light (e.g., the reflected second portion of the light) to Display zero-order light can be suppressed in the formed holographic scene. The techniques can be applied individually or in combination. The technique can be applied to any other display system that suppresses or excludes unwanted light from desired light.

In some examples, the display is configured to suppress higher order display zero-order light, for example, by including irregular or non-uniform display elements having different sizes. The display elements have no periodicity and can form a Voronoi pattern. In some examples, in a holographic scene, the display zero order light can have a much lower power density than the diffracted first portion of the light. That is, display zero-order light can be generated by increasing the signal-to-noise ratio of the holographic scene, e.g. by displaying zero-order light without divergence of the diffracted first part of the light, or This may be suppressed by adjusting the phase of each of the display elements within a predetermined phase range, such as [0,2π], or both. In some examples, displaying zero-order light can be performed by directing the display zero-order light away from the first diffracted portion of light, e.g. Still propagating around the vertical axis, the display is suppressed by illuminating the light at an incident angle on the display and preconfiguring the hologram so that the display zero-order light propagates at the reflected angle. The display zero-order light can be moved outside the holographic scene formed by the diffracted first portion of the light by, for example, adding an additional optical grating structure to direct the display zero-order light away from the holographic scene. You can redirect by directing it further to . Display zero order light can be reflected back and away from the holographic scene. Display zero-order light can also be absorbed before the holographic scene.

In this disclosure, the terms "zero order" and "zero-order" are used interchangeably, and the terms "first order" and "first-order" are used interchangeably. are used interchangeably.

In this disclosure, the terms "zero order" and "zero-order" are used interchangeably, and the terms "first order" and "first-order" are used interchangeably. are used interchangeably.

One aspect of the present disclosure is to illuminate a display with light, a first portion of the light illuminating a display element of the display, and causing the display element of the display to correspond to holographic data. modulating the hologram to i) diffract a first portion of the light to form a holographic scene corresponding to holographic data; and ii) suppress display zero order light in the holographic scene. The present invention features a method for including and suppressing reflected light from a display so that the display zero-order light includes reflected light from the display.

In some examples, illuminating the display with light includes the second portion of the light illuminating a gap between adjacent display elements. Display zero-order light is the second portion of the light reflected at a gap in the display, the second portion of light diffracted at a gap in the display, reflected light from a display element, or reflected from a display cover that covers the display. The light source may include at least one of the following types of light.

The reflected light from the display may be configured to form a dominant order display zero order light and suppress one or more higher order display zero order light, and the display elements may be irregular or It is uneven. In some examples, the display elements form a Voronoi pattern.

In some implementations, the method further includes configuring the hologram such that the diffracted first portion of the light has at least one property that is different from the display zero order light. The at least one characteristic may include at least one of power density, beam divergence, direction of propagation away from the display, or state of polarization.

In some implementations, display zero-order light is suppressed in the holographic scene with light suppression efficiency. Light suppression efficiency is defined as 1 minus the ratio of the amount of display zero order light in a holographic scene with suppression to the amount of display zero order light in a holographic scene without suppression. In some cases, the light suppression efficiency exceeds a predetermined percentage that is one of 50%, 60%, 70%, 80%, 90%, or 99%. In some cases, the light suppression efficiency is 100%.

In some implementations, the method calculates, for each of the plurality of primitives corresponding to the object, the electromagnetic (EM) field propagation from the primitive to the display element in a global three-dimensional (3D) coordinate system. and generating, for each of the display elements, a sum of EM field contributions from the plurality of primitives to the display elements. The holographic data may include the sum of EM field contributions from multiple primitives of the object to display elements of the display. The holographic scene may include reconstructed objects corresponding to the objects.

In some implementations, the holographic data includes respective phases for display elements of the display, and the method adjusts the respective phases for the display elements to have a predetermined phase range. Further comprising configuring. The predetermined phase range may be [0,2π].

In some implementations, adjusting the phase of each of the display elements comprises:
,
adjusting the respective phases according to
During the ceremony,
represents the initial phase value of each phase,
represents the adjusted phase value of each phase, and A and B are constants.

In some implementations, adjusting the respective phases includes adjusting constant A and constant B such that the light suppression efficiency of the holographic scene is maximized. The light suppression efficiency may be greater than 50%, 60%, 70%, 80%, 90%, or 99%. In some cases, adjusting constants A and B includes adjusting constants A and B by a machine vision or machine learning algorithm.

In some implementations, the method includes diverging the diffracted first portion of the light to form a holographic scene and displaying zero-order light in or adjacent to the holographic scene. It further includes: emanating. In some examples, diverging the diffracted first portion of the light includes directing the diffracted first portion of the light through an optical diverging component disposed downstream of the display. and diverging the display zero order light includes directing the display zero order light through an optical diverging component.

In some examples, the light illuminating the display is collimated light. The display zero-order light is collimated before reaching the optically diverging component, and the method further comprises collimating the hologram such that the diffracted first portion of the light is converging before reaching the optically diverging component. configuring.

In some implementations, the holographic data includes a respective phase for each of the display elements. The method may further include, for each of the display elements, constructing a hologram by adding a corresponding phase to the respective phase, the corresponding phase for the display element being such that the holographic scene is the phase of each of the display elements. can be compensated by an optical divergence component to correspond to . The corresponding phase for each of the display elements is
,
can be expressed as,
During the ceremony,
represents the corresponding phase for the display element, λ represents the wavelength of the light, f represents the focal length of the optically diverging component, x and y represent the coordinates of the display element in the coordinate system, and a and b represent a constant.

In some implementations, the holographic scene corresponds to a reconstruction cone with a viewing angle. The method is to move a configuration cone with respect to the display, with respect to a global 3D coordinate system, along a direction perpendicular to the display, a distance corresponding to the focal length of the optically diverging component, the configuration cone Construct the hologram by moving the reconstructed cone, which corresponds to the viewing angle and has an apex angle identical to the viewing angle, and generate holographic data based on the moved constituent cone in the global 3D coordinate system. The method may further include: Multiple primitives of the object may be within the moved configuration cone.

In some implementations, the optical diverging component includes at least one of a concave lens or a holographic optical element (HOE) configured to diffract display zero-order light outside of the holographic scene. It is a focus element.

In some implementations, the optical divergence component is
A focusing element including at least one of a convex lens or a holographic optical element (HOE) configured to diffract display zero order light outside the holographic scene.

In some implementations, the method further includes displaying the holographic scene on a two-dimensional (2D) screen spaced from the display along a direction perpendicular to the display. The method may further include moving the 2D screen to obtain different slices of the holographic scene on the 2D screen.

In some implementations, the method further includes directing light to illuminate the display. In some examples, directing the light to illuminate the display includes directing the light through a beam splitter, and the diffracted first portion of the light and the display zero order light are transmitted through the beam splitter. let

In some implementations, illuminating the display with light includes illuminating the display with light at normal incidence.

In some implementations, the diffracted first portion of the light forms a reconstruction cone with a viewing angle, and illuminating the display with light includes light with an incident angle greater than half the viewing angle. Including illuminating the display. In some examples, the method includes a method in which the first diffracted portion of the light has a reconstruction cone that is the same as the reconstruction cone that would be formed by the first diffracted portion of the light if the light were normally incident on the display. The method further includes configuring the hologram to form a cone.

In some examples, the holographic data includes a respective phase for each of the display elements. The method may further include, for each of the display elements, constructing a hologram by adding a corresponding phase to the respective phase, the corresponding phase for the display element being such that the holographic scene is the phase of each of the display elements. can be compensated by the angle of incidence to correspond to .

In some examples, the corresponding phase for each of the display elements is
,
can be expressed as,
During the ceremony,
represents the corresponding phase for the display element, λ represents the wavelength of the light, x and y represent the coordinates of the display element in the global 3D coordinate system, and θ represents the angle corresponding to the angle of incidence.

In some examples, configuring the hologram includes moving a configuration cone relative to the display with respect to a global 3D coordinate system, the configuration cone corresponding to the reconstruction cone and having a field of view of the reconstruction cone. and generating holographic data based on the moved constituent cone in a global 3D coordinate system.

In some examples, moving the configuration cone relative to the display in the global 3D coordinate system is rotating the configuration cone at a rotation angle relative to the surface of the display relative to the global 3D coordinate system, and the rotation including rotating, where the angle corresponds to the angle of incidence.

In some implementations, the method further includes blocking display zero order light from appearing in the holographic scene. The light suppression efficiency of the holographic scene can be 100%. In some examples, blocking the display zero-order light includes directing the display zero-order light toward an optical blocking component located downstream of the display. The method can further include directing the diffracted first portion of the light to transmit through the optical blocking component with transmission efficiency to form a holographic scene. The transmission efficiency may not be less than a predetermined ratio. The predetermined ratio may be 50%, 60%, 70%, 80%, 90%, or 99%.

In some implementations, the optical blocking component is configured to transmit a first beam of light having an angle less than the predetermined angle and block a second beam of light having an angle greater than the predetermined angle. The predetermined angle is smaller than the angle of incidence and larger than half the viewing angle. The optical blocking component can include multiple microstructures or nanostructures, metamaterial layers, or optically anisotropic films.

In some implementations, the method includes directing light to illuminate the display by directing the light through an optical diffractive component on the substrate that is configured to diffract the light at an angle of incidence. It further includes: Directing the light to illuminate the display may include directing the light through a waveguide coupler to an optical diffractive component, through a coupling prism to an optical diffractive component, or through a substrate. directing light through a wedge-shaped surface to an optical diffractive component.

In some implementations, the optical diffractive component is formed on a first surface of the substrate facing the display, and the optical blocking component is formed on a first surface of the substrate opposite the first surface. It is formed on the surface of 2.

In some implementations, the method further includes redirecting the display zero order light away from the holographic scene. The light suppression efficiency of the holographic scene can be 100%.

In some implementations, redirecting the display zero-order light away from the holographic scene includes diffracting the display zero-order light away from the holographic scene by an optical redirection component located downstream of the display. include. The optical redirection component can be configured to transmit the diffracted first portion of the light to form a holographic scene.

In some implementations, the optical redirection component directs the display zero-order light in a three-dimensional (3D) direction along at least one of an upward direction, a downward direction, a leftward direction, a rightward direction, or a combination thereof. It is configured to be diffracted in space and out of the holographic scene.

In some implementations, the optical redirection component diffracts the first light beam having the same angle as the predetermined angle substantially more than the second light beam having an angle different from the predetermined angle. The predetermined angle is substantially the same as the angle of incidence. The optical redirection component can include a Bragg grating.

In some implementations, the optical diffractive component is formed on a first surface of the substrate facing the display, and the optical redirecting component is formed on a first surface of the substrate opposite the first surface. It is formed on the surface of 2.

In some cases, the angle of incidence of the light is negative and the angle of diffraction of the display zero order light diffracted by the optical redirection component is negative. In some cases, the angle of incidence of the light is positive and the diffraction angle of the display zero order light diffracted by the optical redirection component is positive. In some cases, the angle of incidence of the light is negative and the angle of diffraction of the display zero order light diffracted by the optical redirection component is positive. In some cases, the angle of incidence of the light is positive and the angle of diffraction of the display zero order light diffracted by the optical redirection component is negative.

In some implementations, the optical redirection component is covered by a second substrate. The method further includes a light absorber formed on a side of the second substrate or at least one of the sides of the substrate, the light absorber being redirected by the optical redirecting component and between the second substrate and the surrounding medium. The display may include absorbing zero-order light that is reflected by the interface.

In some implementations, the second substrate includes an anti-reflective coating on a surface of the second substrate opposite the optical redirection component, the anti-reflective coating configured to transmit the display zero-order light. has been done.

In some implementations, the display zero-order light is p-polarized before arriving at the second substrate, and the optical redirection component causes the display zero-order light to completely transmit through the second substrate. The display is configured to diffract zero-order light into the interface between the second substrate and the surrounding medium at Brewster's angle.

In some implementations, the method further includes converting the polarization state of the display zero-order light from s-polarization to p-polarization before the display zero-order light reaches the second substrate. In some cases, converting the polarization state of the display zero-order light includes converting the polarization state of the display zero-order light by an optical polarization device positioned upstream of the optical redirection component with respect to the display. include.

In some cases, converting the polarization state of the display zero-order light includes converting the polarization state of the display zero-order light by an optical polarization device positioned downstream of the optical redirection component with respect to the display. include. The optical polarization device can include an optical retarder and an optical polarizer disposed in series downstream of the optical redirection component, the optical retarder on a side of the second substrate opposite the optical redirection component. The optical polarizer can be formed and covered by a third substrate. In some examples, the optical retarder includes a broadband half-wave plate and the optical polarizer includes a linear polarizer.

In some implementations, the second substrate includes a first side of the top of the optical redirection component and a second side opposite the first side. An optical blocking component can be formed on the second side of the second substrate and transmitting the diffracted first portion of the light and absorbing the display zero order light diffracted by the optical redirecting component. is configured to do so.

In some implementations, the optical blocking component is configured to transmit a first beam of light having an angle less than the predetermined angle and absorb a second beam of light having an angle greater than the predetermined angle. It includes an optical anisotropic transmitter configured as follows. The predetermined angle can be greater than half the viewing angle and less than the diffraction angle at which display zero order light is diffracted by the optical redirection component.

In some implementations, the optical redirection component is configured to diffract the display zero-order light so that it is incident on the interface between the second substrate and the surrounding medium at an angle that is greater than the critical angle. Therefore, the display zero order light that is diffracted by the optical diffractive component is completely reflected at the interface. Light absorbers may be formed on the sides of the substrate and the second substrate and configured to absorb completely reflected display zero order light.

In some implementations, the light includes a plurality of different colors of light, and the optical diffractive component is configured to diffract the plurality of different colors of light at an angle of incidence on the display.

In some implementations, the optical redirection component includes a respective optical redirection subcomponent for each of the plurality of different colors of light. In some examples, respective optical redirection subcomponents for multiple different colors of light can be recorded on the same recording structure. In some examples, each optical redirection subcomponent for a plurality of different colors of light is recorded in a different corresponding recording structure.

In some implementations, the optical redirection component is configured to diffract light of a plurality of different colors toward different directions and at different diffraction angles in 3D space. The optical redirection component can be configured to diffract at least one of the plurality of different colors of light to be incident at the interface at at least one Brewster's angle. The interface can include one of an interface between a top substrate and a surrounding medium or an interface between two adjacent substrates.

In some implementations, the optical redirection component is configured to diffract the first color of light and the second color of light in the plane and the third color of light orthogonal to the plane. . In some implementations, the optical redirection component includes at least two different optical redirection subcomponents configured to diffract the same color of light of the plurality of different colors of light. Two different optical redirection sub-components can be arranged sequentially in the optical redirection component.

In some implementations, directing the light to illuminate the display includes sequentially directing a plurality of different colors of light to illuminate the display in a series of time periods. In some implementations, the optical redirection component diffracts light of a first color in a first state during a first time period and diffracts light of a second color in a second state during a second time period. A switchable optical redirection subcomponent configured to transmit light. In some implementations, the optical redirection component diffracts light of a first color in a first state during a first time period and diffracts light of a second color in a second state during a second time period. A switchable optical redirection subcomponent configured to diffract light.

In some implementations, the plurality of different colors of light include a first color of light and a second color of light, and the first color of light has a shorter wavelength than the second color of light. and in the optical redirection component, a first optical redirection sub-component for the first color of light is located closer to the display than a second optical redirection sub-component for the second color of light. There is.

In some implementations, the fringe planes of at least two optical redirection subcomponents for at least two different colors of light are oriented in substantially different directions.

In some implementations, the optical redirection component includes a first optical redirection subcomponent configured to diffract light of a first color and a first optical redirection subcomponent configured to diffract light of a second color. a second optical redirection sub-component arranged between the first optical redirection sub-component and the second optical redirection sub-component, and wherein the first color of light is directed to the second optical redirection sub-component; at least one optical polarization device configured to convert the polarization state of the first color of light for transmission through the element. The at least one optical polarization device may include an optical retarder and an optical polarizer disposed in series downstream of the first optical redirection subcomponent.

In some cases, half of the viewing angle is within the range of -10 degrees to 10 degrees, or within the range of -5 degrees to 5 degrees. In some cases, the angle of incidence is -6 degrees or 6 degrees.

Another aspect of the present disclosure is to illuminate a display with light, wherein a portion of the light illuminates a display element of the display, while suppressing display zero-order light present in the holographic scene. generating a holographic scene by diffracting a portion of the light, the display zero order light comprising reflected light from the display.

In some implementations, suppressing the display zero order light present in the holographic scene includes diverging the display zero order light.

In some implementations, generating a holographic scene by diffracting the portion of light includes modulating a display element with a hologram. Suppressing the display zero order light present in the holographic scene can include adjusting the phase range of the hologram.

In some implementations, illuminating the display with light includes illuminating the display with light at an angle of incidence, and suppressing the display zero-order light present in the holographic scene includes a portion of the light being , may include modulating a portion of the light with a hologram configured to be diffracted by the display element at a diffraction angle different from the angle of reflection at which the reflected light is reflected. In some cases, suppressing the display zero order light present in the holographic scene includes blocking the display zero order light with an incident angle dependent material. The angle of incidence dependent material can include a metamaterial or an optically anisotropic material.

In some implementations, suppressing the display zero order light present in the holographic scene includes redirecting the display zero order light. Redirecting the display zero order light may include diffracting the display zero order light with an optical diffractive component. The light may include light of different colors, and redirecting the display zero-order light may include diffracting the light of different colors in different directions in three-dimensional (3D) space.

In some implementations, suppressing the display zero-order light present in the holographic scene includes suppressing the display zero-order light with a light suppression efficiency that is greater than or equal to a predetermined ratio. Light suppression efficiency is defined as 1 minus the ratio of the amount of display zero order light in the holographic scene with suppression to the amount of display zero order light without suppression. The predetermined ratio may be 50%, 60%, 70%, 80%, 90%, or 100%.

Another feature of the disclosure features an optical device that includes an optical diffractive component and an optical blocking component. The optical diffractive component is configured to diffract light at an angle of incidence to illuminate the display with a portion of the light that illuminates the display element of the display, and the optical blocking component is configured to diffract light at an angle of incidence to illuminate the display with a portion of the light that is diffracted by the display element. The display is configured to block the display zero-order light in the holographic scene formed by the portion of the light, the display zero-order light including reflected light from the display.

In some implementations, an optical device is configured to perform a method as described above.

In some implementations, the display is configured to diffract a portion of the light modulated with a hologram corresponding to the holographic data to form a holographic scene, and the optical blocking component is configured to diffract a portion of the light. is configured to transmit the diffracted portion of the image to form a holographic scene. The diffracted portion of the light can form a reconstruction cone with a viewing angle, and the angle of incidence can be greater than half the viewing angle.

The optical blocking component may be configured to transmit a first beam of light having an angle less than a predetermined angle and block a second beam of light having an angle greater than a predetermined angle; The angle can be smaller than the angle of incidence and larger than half the viewing angle.

In some implementations, the optical blocking component includes a metamaterial layer or an optically anisotropic film. In some implementations, the optical blocking component includes multiple microstructures or multiple nanostructures.

In some implementations, the optical device further includes a substrate having double sides. Optical diffractive and optical blocking components can be formed on both sides of the substrate.

Another aspect of the present disclosure includes forming an optical diffractive component on a first side of a substrate and forming an optical blocking component on a second side of the substrate opposite the first side. A method of manufacturing an optical device as described above, comprising:

Another aspect of the disclosure features an optical device that includes an optical diffraction component and an optical redirection component. The optical diffractive component is configured to diffract light at an angle of incidence onto a display that includes a plurality of display elements spaced apart by gaps on the display. The display is configured to diffract a portion of the light that impinges on the display element. The optical redirection component is configured to transmit a portion of the light to form a holographic scene and redirect the zero-order light away from the holographic scene in three-dimensional (3D) space, and the optical redirection component is configured to transmit a portion of light to form a holographic scene and redirect the zero-order light away from the holographic scene in three-dimensional (3D) space. Zero-order light includes reflected light from the display.

In some examples, the optical redirection component includes a Bragg grating.

In some implementations, the optical diffractive component is formed on a first side of the substrate facing the display, and the optical redirecting component is formed on a second side of the substrate opposite the first side. is formed on the side of

In some implementations, the optical device further includes a second substrate covering the optical redirection component. In some implementations, the optical device further includes a light absorber formed on at least one of the side of the substrate or the side of the second substrate, the light absorber being redirected by the optical redirection component. , and configured to absorb display zero order light reflected by the interface between the second substrate and the surrounding medium.

In some implementations, the optical device further includes an anti-reflective coating formed on the second substrate and opposite the optical redirection component, the anti-reflection coating being redirected by the optical redirection component. The display is configured to transmit zero-order light.

In some implementations, the optical device is an optical polarization device configured to convert the polarization state of the display zero-order light from s-polarization to p-polarization before the display zero-order light arrives at the second substrate. further comprising an optical redirection component that diffracts the display zero order light to an interface between the second substrate and the surrounding medium such that the display zero order light is transmitted through the second substrate. The beam is configured to be incident at Brewster's angle. An optical polarization device can include an optical retarder and a linear polarizer arranged together in series.

In some implementations, the optical polarization device is placed upstream of the optical redirection component with respect to the display. In some implementations, the optical polarization device is formed on the side of the second substrate opposite the optical redirection component, and the optical polarization device is covered by the third substrate.

In some implementations, the optical device further includes an optical blocking component formed on a side of the second substrate opposite the optical redirecting component, the optical blocking component transmitting a portion of the light; The display is configured to absorb zero order light diffracted by the optical redirection component. The optical blocking component can include an optically anisotropic transmitter.

In some implementations, the optical redirection component is configured to diffract the display zero order light into incidence at an angle greater than a critical angle on the interface between the second substrate and the surrounding medium. , and thus the display zero-order light that is diffracted by the optical diffractive component is completely reflected at the interface.

In some implementations, the light includes multiple different colors of light. The optical diffraction component is configured to diffract light of multiple different colors at an angle of incidence on the display, and the optical redirection component is configured to diffract the zero-order light of multiple different colors of light reflected by the display. , can be configured to be diffracted toward different directions in 3D space at different diffraction angles, and the display zero-order light includes light reflected by a plurality of different colors of light by the display.

In some implementations, the optical diffractive component includes a plurality of holographic gratings for a plurality of different colors of light, each of the plurality of holographic gratings having a respective one of a plurality of different colors at an angle of incidence on the display. It is designed to diffract colored light.

In some implementations, the optical redirecting component includes a plurality of redirecting holographic gratings for displaying zero-order light of a plurality of different colors of light, each of the plurality of redirecting holographic gratings displaying a plurality of different colors of light. The display of each color of light is configured to diffract the zero-order light at a respective diffraction angle toward a respective direction in 3D space.

In some implementations, the optical redirection component includes at least two different redirection holographic gratings configured to diffract display zero order light of the same color of light of the plurality of different colors of light.

In some implementations, the optical redirection component diffracts light of a first color in a first state during a first time period and diffracts light of a second color in a second state during a second time period. A switchable redirecting holographic grating configured to transmit light.

In some implementations, the optical redirection component diffracts light of a first color in a first state during a first time period and diffracts light of a second color in a second state during a second time period. includes a switchable redirecting holographic grating configured to diffract light.

In some implementations, the plurality of different colors of light include a first color of light and a second color of light, and the first color of light has a shorter wavelength than the second color of light. and in the optical redirecting component, a first redirecting holographic grating for the first color of light is located closer to the display than a second redirecting holographic grating for the second color of light.

In some implementations, the fringe planes of at least two redirecting holographic gratings for at least two different colors of light are oriented in substantially different directions.

In some implementations, the optical redirecting component includes a first redirecting holographic grating configured to diffract light of a first color and a first redirecting holographic grating configured to diffract light of a second color. a second redirecting holographic grating; and a second redirecting holographic grating arranged between the first redirecting holographic grating and the second redirecting holographic grating, the first color of light being transmitted through the second redirecting holographic grating. at least one optical polarization device configured to convert the polarization state of the first color light so as to convert the polarization state of the first color light.

In some implementations, the optical device is configured to perform the method described above.

Another aspect of the disclosure includes forming an optical diffractive component on a first side of a substrate and forming an optical redirecting component on a second side of the substrate opposite the first side. A method of manufacturing an optical device as described above, comprising:

Another aspect of the present disclosure provides a display that includes display elements separated by a gap on the display and an optical device configured to illuminate the display with light, a portion of the light being illuminated onto the display element. Features a system that includes: The system is configured to diffract a portion of the light to form a holographic scene while suppressing display zero order light within the holographic scene. The display zero order light may include at least one of reflected light at a gap, diffracted light at a gap, reflected light at a display element, or reflected light at a display cover over the display.

In some implementations, the system is coupled to a display and modulates a display element of the display with a hologram corresponding to the holographic data to diffract a portion of the light to generate a hologram corresponding to the holographic data. The controller further includes a controller configured to form the scene. The hologram can be configured such that display zero order light is suppressed within the holographic scene.

In some implementations, the system further includes a computing device configured to generate one or more object primitives corresponding to the holographic scene. The system may be configured to perform a method such as that described above. The optical device may include one or more of the optical devices described above.

In some implementations, the system further includes an optical diverging device positioned downstream of the optical device and configured to diverge the display zero order light within the holographic scene. The light that illuminates the display is collimated light. The display zero order light is collimated before reaching the optical diverging device, and the hologram is configured such that the diffracted portion of the light is converging before reaching the optical diverging device.
The optically diverging device can include optically diverging components as described above.

In some implementations, the system further includes a two-dimensional (2D) screen positioned downstream of the display. In some implementations, the optical device includes a beam splitter. In some implementations, the optical device includes a waveguide with an in-coupler and an out-coupler. In some implementations, the optical device includes a light guide that includes an optical coupler and an optical diffractive component. The optical coupler can include a coupling prism. The optical coupler can also include a wedge-shaped substrate.

Another aspect of the disclosure features a method of making a system such as described above.

Another aspect of the present disclosure expands an input light beam in at least two dimensions by diffracting the input light beam to adjust the beam size of the input light beam in at least two dimensions to form an output light beam. an optical device including at least two beam expanders configured to generate beam expanders. Beam size can include width and height.

In some implementations, each of the at least two beam expanders includes a respective optical diffraction device. The input light beam may include a plurality of different colors of light, and each optical diffraction device is configured to diffract a plurality of different colors of light at respective diffraction angles that are substantially the same as each other. Can be done.

In some examples, each optical diffraction device is capable of transmitting light of different colors while suppressing crosstalk between the different colors when light of different colors is incident on the respective optical diffraction device. It is constructed to separate the individual colors of light.

In some implementations, each optical diffractive device includes at least two optical diffractive components and at least one color selective polarizer.

In some implementations, each optical diffractive device includes at least two optical diffractive components and at least one reflective layer. The at least one reflective layer may be configured for total internal reflection of at least one color of light.

In some implementations, each optical diffractive device includes at least one of one or more transmissive diffractive structures or one or more reflective diffractive structures.

In some implementations, the at least two beam expanders include a first primary configured to expand the input light beam in a first of the at least two dimensions to produce an intermediate light beam. an original beam expander and a second one-dimensional beam expander configured to expand the intermediate beam of light in a second of the at least two dimensions to produce an output beam of light. The intermediate light beam has a larger beam size than the input light beam of the first dimension and the same beam size as the input light beam of the second dimension, and the output light beam has a larger beam size than the input light beam of the second dimension. also has a large beam size and the same beam size as the intermediate light beam of the first dimension.

In some implementations, the optical device uses at least one of a free-space aerial geometry, a monolithic or segmented substrate, or one or more coupling elements to couple the intermediate light beam to the first The first one-dimensional beam expander is configured to couple from the first one-dimensional beam expander to the second one-dimensional beam expander.

In some implementations, the intermediate input beam includes collinearly collimated light of two or more colors, and the one or more coupling elements include collinearly collimated light of two or more colors. The light beam is configured to convert light into two or more independent parallel but non-colinear light beams having two or more corresponding colors.

This disclosure also describes, among other things, methods, apparatus, devices, and systems for displaying three-dimensional (3D) objects by individually diffracting light of different colors. The present disclosure provides techniques that can efficiently separate light of different colors or wavelengths to suppress (eg, reduce or eliminate) crosstalk between colors or wavelengths. The technique also allows light to propagate without diffraction through an optical diffractive device and prevent it from hitting the display at undesirable angles, thereby suppressing undesirable effects such as ghost images. The technique allows multicolor three-dimensional light fields or images to be reconstructed sequentially or simultaneously with little or no crosstalk. The technique makes it possible to implement an illumination system to provide nearly vertically polarized beams of multiple different colors with relatively large angles of incidence. The technique therefore involves presenting a light field or image to a viewer (e.g. an observer or user) in front of a display without interference with the illuminator and power losses due to e.g. reflection, diffraction and/or scattering. and enable. The technology also makes it possible to implement compact optical systems for displaying three-dimensional objects.

The present disclosure provides techniques that can overcome the limitations present in known techniques. As an example, the techniques disclosed herein can be implemented without the use of cumbersome wearable devices such as "3D glasses." As another example, the techniques disclosed herein may be affected by the accuracy of the tracking mechanism, the quality of the display device, relatively long processing times and/or relatively high computational demands, and/or by presenting objects to multiple viewers simultaneously. It can be optionally implemented without being limited by the inability to display. As a further example, the technology can be implemented without specialized tools and software to develop content that extends beyond those used for traditional 3D content creation. Various embodiments may exhibit one or more of the aforementioned advantages. For example, certain implementations of the present disclosure create real-time, full-color, authentic 3D images that appear to be real 3D objects in the world and that can be viewed simultaneously by multiple viewers from different points without obstruction. can be generated.

One aspect of the present disclosure provides for displaying a display by calculating, for each of a plurality of primitives corresponding to an object in three-dimensional (3D) space, the electromagnetic (EM) field propagation from the primitive to the element in a 3D coordinate system. The method includes: determining an EM field contribution to each of the plurality of elements; and generating, for each of the plurality of elements, a sum of EM field contributions from the plurality of primitives to the element.

The EM field contribution can include at least one of a phase contribution or an amplitude contribution. The primitives may include at least one of point primitives, line primitives, or polygon primitives. The primitives may include line primitives that include at least one of a gradient color, a texture color, or any surface shading effect. Primitives may also include polygon primitives that include at least one of a gradient color, a texture color, or any surface shading effect. Multiple primitives can be indexed in a particular order.

In some implementations, the method further includes obtaining respective primitive data for each of the plurality of primitives. The respective primitive data for each of the plurality of primitives may include color information for each of the primitives, and the determined EM field contribution for each of the elements includes information corresponding to the color information for each of the primitives. The color information may include at least one of a texture color or a gradient color. Respective primitive data for each of the plurality of primitives may include texture information for the primitive. Respective primitive data for each of the plurality of primitives may include shading information on one or more surfaces of the primitive. The shading information may include modulation of at least one of color or brightness on one or more surfaces of the primitive.

In some implementations, the respective primitive data for each of the plurality of primitives includes coordinate information for the primitive in a 3D coordinate system. The coordinate information of each of the plurality of elements in the 3D coordinate system can be determined based on the coordinate information of each of the plurality of primitives in the 3D coordinate system. Respective coordinate information for each of the elements may correspond to a logical memory address of the element stored in memory.

Determining the EM field contribution to each of the plurality of elements for each of the plurality of primitives includes determining the EM field contribution of each of the plurality of primitives to each of the plurality of elements based on coordinate information of each of the elements and coordinate information of each of the primitives in a 3D coordinate system. and determining at least one distance between. In some examples, for each of the plurality of primitives, determining the EM field contribution to each of the plurality of elements includes coordinate information of each of the first primitives and coordinate information of each of the first elements. determining a first distance between a first primitive of the plurality of primitives and a first element of the plurality of elements based on the first distance and the first element; determining a second distance between the first primitive and a second element of the plurality of elements based on the distance between the first primitive and the second element. The distance between the first element and the second element can be predetermined based on the pitch of the plurality of elements of the display.

In some examples, at least one of the plurality of primitives is a line primitive including a first endpoint and a second endpoint, and determining the at least one distance between the element and the primitive comprises: determining a first distance between the element and a first endpoint of the line primitive; and determining a second distance between the element and a second endpoint of the line primitive. In some examples, at least one of the plurality of primitives is a triangular primitive that includes a first endpoint, a second endpoint, and a third endpoint, and the at least one distance between the element and the primitive Determining includes determining a first distance between the element and a first endpoint of the triangle primitive, and determining a second distance between the element and a second endpoint of the triangle primitive. and determining a third distance between the element and a third point of the triangle primitive.

In some implementations, determining the EM field contribution to each of the plurality of elements for each of the plurality of primitives includes determining the EM field contribution to each of the plurality of elements for each of the plurality of primitives based on a predetermined formula for the primitive and at least one distance from the primitive to the element. including determining the EM field contribution. In some cases, the predetermined formula is determined by analytically calculating the EM field propagation from the primitive to the element. In some cases, the predetermined equations are determined by solving Maxwell's equations. Maxwell's equations can be solved by providing boundary conditions defined at the surface of the display. The boundary conditions can include Dirichlet boundary conditions or Cauchy boundary conditions. The primitives and elements may be in 3D space, and the surface of the display may form part of the bounding surface of the 3D space. In some cases, the predetermined equation includes at least one of a function including a sine function, a cosine function, or an exponential function, and determining the EM field contribution comprises a function in a table stored in memory. identifying at least one value of the .

In some implementations, determining the EM field contribution to each of the plurality of elements for each of the plurality of primitives and generating the sum of field contributions for each of the plurality of elements includes determining a first EM field contribution from the plurality of elements to a first element of the plurality of elements; summing the first EM field contribution for the first element; determining a second EM field contribution to a second element of the second element; and summing the second EM field contribution for the second element. Determining a first EM field contribution from the plurality of primitives to the first element includes determining an EM field contribution from the first primitive of the plurality to the first element; and determining an EM field contribution from a second of the primitives to the first element.

In some implementations, determining the EM field contribution to each of the plurality of elements for each of the plurality of primitives includes determining the EM field contribution to each of the plurality of elements from a first primitive of the plurality of primitives to each of the plurality of elements. and determining a second respective EM field contribution from a second primitive of the plurality of primitives to each of the plurality of elements, Generating the sum of the field contributions for each of the elements involves accumulating the EM field contributions for the element by adding the second respective EM field contribution to the first respective EM field contribution. can be included. determining a first respective EM field contribution from the first primitive to each of the plurality of elements; determining a second respective EM field contribution from the second primitive to each of the plurality of elements; can be executed in parallel.

Determining the EM field contribution to each of the plurality of elements for each of the plurality of primitives includes determining the EM field contribution from the first primitive of the plurality of primitives to the first element of the plurality of elements. The method may include, in parallel, determining the field contribution and determining a second EM field contribution from a second of the plurality of primitives to the first element.

In some implementations, the method is to generate a respective control signal for each of the plurality of elements based on the sum of EM field contributions to the element from the plurality of primitives, the respective control signal being , for adjusting at least one property of the element based on the sum of EM field contributions from the plurality of primitives to the element. The at least one property of the element can include at least one of refractive index, amplitude index, birefringence, or retardation. Each control signal may include an electrical signal, an optical signal, a magnetic signal, or an acoustic signal. In some cases, the method further includes multiplying the sum of the field contributions of each of the elements by a scale factor to obtain a scaled sum of the field contributions, and the respective control signal is a sum of the field contributions for the element. generated based on a scaled sum of . In some cases, the method further includes normalizing the sum of field contributions for each of the elements, and each control signal is based on the normalized sum of field contributions for the elements. The method can also include transmitting respective control signals to the elements.

In some implementations, the method is to transmit a control signal to the illuminator, the control signal indicating to cause the illuminator to emit light on the display. It further includes: The control signal may be transmitted in response to determining completion of obtaining the sum of field contributions for each of the plurality of elements. The modulated elements of the display can propagate light in different directions to form a volumetric light field corresponding to an object in 3D space. The volume light field may correspond to a solution of Maxwell's equations with boundary conditions defined by the modulated elements of the display. The light can include white light, and the display can be configured to diffract the white light into light having different colors.

In some implementations, the method further includes representing the value using a fixed point representation during the calculation. Each of the values can be represented as an integer with an implicit scale factor.

In some implementations, the method further includes performing the mathematical function using a fixed point representation. The mathematical function can include at least one of sine, cosine, and arctangent. Executing the mathematical function includes receiving an expression in a first fixed-point format and outputting a value in a second fixed-point format having a different precision level than the first fixed-point format. can be included. Performing a math function can include consulting a table for math function calculations, where the table can include fully enumerated lookup tables, interpolated tables, semi-table based polynomial functions, and Contains at least one half-table based on a complete minimax polynomial. Performing a mathematical function may include applying special range reductions to the input. Performing the mathematical function may include converting the trigonometric calculation from the range [-π, π] to a signed-2 compliment representation in the range [-1, 1].

Another aspect of the present disclosure includes obtaining primitive data for each of a plurality of primitives corresponding to an object in three-dimensional (3D) space; calculating a first respective electromagnetic (EM) field contribution to each of the plurality of elements of the display; and a second respective EM field contribution from a second of the plurality of primitives to each of the plurality of elements of the display. A method comprising: calculating. Computing a first respective EM field contribution from the first primitive is at least partially parallel to computing a second respective EM field contribution from the second primitive.

In some implementations, calculating the first EM field contribution from the first primitive to the first element of the plurality of elements includes calculating the first EM field contribution from the second primitive of the plurality of elements to the first element of the plurality of primitives. In parallel with calculating the second EM field contribution to the element. The method can include calculating a respective EM field contribution from each of the plurality of primitives to each of the plurality of elements. Computation of each EM field contribution involves expanding the geometry of the object into multiple elements, applying visibility tests before packing the wavefront, and making decisions or communicating between parallel computations for different primitives. At least one of the following can be omitted. The calculation of each EM field contribution can be done by tuning parallel computations for different primitives to speed, cost, size, or energy optimization, between starting drawing and results ready for display. The method may be configured to cause at least one of: lowering latency, improving accuracy by using a fixed point representation, and optimizing calculation speed by optimizing mathematical functions. can.

In some implementations, the method further includes representing the value using a fixed point representation during the calculation. Representing values using fixed-point representation denormalizes floats for gradual underflow, handles NaN results from operations involving division by zero, and changes floating-point rounding modes. and/or generating a floating point exception to the operating system.

In some implementations, the method comprises, for each of the plurality of elements, adding a second respective EM field contribution for the element to a first respective EM field contribution for the element. The method further includes accumulating the EM field contributions.

In some implementations, the method is to generate a respective control signal for each of the plurality of elements based on the sum of EM field contributions to the element from the plurality of primitives, the respective control signal being , for adjusting at least one property of the element based on the sum of EM field contributions from the plurality of primitives to the element.

In some implementations, the method includes scaling the first primitive adjacent to the second primitive by a predetermined factor such that the reconstruction of the first primitive does not overlap the reconstruction of the second primitive. further including. The predetermined factor can be determined based at least in part on the resolution of the display. The method is to obtain respective primitive data for each of the plurality of primitives, wherein the respective primitive data for each of the plurality of primitives includes coordinate information for each of the primitives in a 3D coordinate system. and determining new respective coordinate information of the first primitives based on the respective coordinate information of the first primitives and the predetermined coefficients. The method may further include determining an EM field contribution from the first primitive to each of the plurality of elements based on the new respective coordinate information of the first primitive. The method can further include scaling the second primitive by a predetermined factor. The first primitive and the second primitive may share a common portion, and scaling the first primitive includes scaling the common portion of the first primitive. Scaling the first primitive may include scaling the first primitive in a predetermined direction.

Another aspect of the present disclosure is to obtain primitive data for each of a plurality of primitives corresponding to an object in three-dimensional (3D) space, and to obtain respective primitive data for a first primitive and a second primitive. using a predetermined factor to scale a first primitive adjacent to a second primitive by a predetermined factor; and updating respective primitive data for the first primitive based on the result of the scaling. Features a method.

In some implementations, the respective primitive data of each of the plurality of primitives includes respective coordinate information of the primitive in a 3D coordinate system, and updating the respective primitive data includes information about the respective coordinates of the first primitive. determining new respective coordinate information for the first primitive based on the information and the predetermined coefficients.

In some implementations, the predetermined coefficients are determined such that the reconstruction of the first primitive does not overlap the reconstruction of the second primitive in 3D space.

In some implementations, scaling is such that the gap between the reconstruction of the first and second primitives in 3D space separates the first and second primitives and eliminates the effect of overlapping. It is executed in such a way that it is large enough to be minimal and small enough to make the reconstruction appear seamless.

In some implementations, the predetermined factor is based at least in part on the resolution of the display, or on the actual or assumed distance from the viewer to the display, or on the z-depth of the primitive in the 3D space of the display. determined based on.

In some implementations, the method further includes storing updated primitive data for the first primitive in a buffer.

In some implementations, scaling is performed during the object rendering process to obtain primitive data for each of the plurality of primitives.

In some implementations, the method further includes transmitting updated primitive data for the plurality of primitives to the controller, the controller transmitting the updated primitive data for the plurality of primitives to the plurality of primitives based on the updated primitive data for the plurality of primitives. is configured to determine a respective electromagnetic (EM) field contribution from each of the plurality of elements to each of the plurality of elements of the display.

In some implementations, the method further includes determining an EM field contribution from the first primitive to each of the plurality of elements of the display based on the updated primitive data of the first primitive.

In some implementations, the method further includes scaling the second primitive by a predetermined factor.

In some implementations, the first primitive and the second primitive share a common portion, and scaling the first primitive includes scaling the common portion of the first primitive.

In some implementations, scaling the first primitive includes scaling the first primitive in a predetermined direction.

In some implementations, scaling the first primitive includes scaling a first portion of the first primitive by a first predetermined factor and scaling the first portion of the first primitive by a second predetermined factor. , the first predetermined factor being different from the second predetermined factor.

Another aspect of the present disclosure provides a plurality of discrete cosine transform (DCT) weights of an image mapped onto a particular surface of a particular primitive of a plurality of primitives corresponding to an object in three-dimensional (3D) space. and determining a respective EM field contribution from a particular primitive to each of a plurality of elements of a display by taking into account the effects of a plurality of DCT weights of the image. do.

In some implementations, a method includes: determining a resolution for an image mapped on a specified surface of a particular primitive; and determining a plurality of DCT weights for the image based on the resolution. Including further.

In some implementations, the method further includes decoding the DCT weights of the image to obtain a respective DCT amplitude for each pixel of the image.

In some implementations, the method further includes storing a value associated with a DCT amplitude of each pixel of the image along with primitive data for the particular primitive. Determining the respective EM field contributions includes calculating the respective EM field contributions from the particular primitive to each of the plurality of elements using values associated with respective DCT amplitudes of pixels of the image. be able to.

In some implementations, the method further includes selecting particular DCT terms to be included in determining each EM field contribution, each of the particular DCT terms having a respective DCT weight higher than a predetermined threshold. has.

Another aspect of the present disclosure is to obtain information for a given primitive and an occluder for the given primitive, wherein the given primitive is a plurality of primitives corresponding to objects in three-dimensional (3D) space. and determining which one or more particular elements of the plurality of elements of the display do not contribute to the reconstruction of the given primitive as an effect of the occluder. do.

In some implementations, the method further includes storing information for particular elements along with information for given primitives and occluders.

In some implementations, the determining is performed during an object rendering process to obtain primitive data for a plurality of primitives.

In some implementations, the method calculates the electromagnetic (EM) contribution for the plurality of primitives to the plurality of elements of the display using the stored information of a particular element, along with the given primitive and occluder information. further comprising transmitting to a controller configured to:

In some implementations, the method determines one of the particular elements from the plurality of primitives by excluding, for each of the particular elements, the EM field contribution from the given primitive to one of the particular elements. further comprising generating a sum of electromagnetic (EM) field contributions to one of the EM fields.

In some implementations, the method further includes generating, for each of the plurality of elements other than the particular element, a respective sum of EM field contributions from the plurality of primitives to the element.

In some implementations, the method further includes masking the EM field contribution of the particular element to the given primitive.

In some implementations, determining one or more particular elements involves connecting a given primitive to an endpoint of an occluder, extending the connection to the display, and connecting the connection to the display at the intersection of the connection and the display. and determining that a particular range defined by the intersection is a particular element that does not contribute to the reconstruction of a given primitive due to the effect of the occluder.

Another aspect of the invention is to obtain information about a given primitive and an occluder for the given primitive, wherein the given primitive is a plurality of primitives corresponding to objects in three-dimensional (3D) space. and determining, for each of a plurality of elements of the display, a respective portion of a given primitive that does not make an electromagnetic (EM) field contribution to the element as an effect of the occluder. Features a method.

In some implementations, the method further includes storing information for each portion of the given primitive along with information for the given primitive and the occluder.

In some implementations, the determining is performed during an object rendering process to obtain primitive data for a plurality of primitives.

In some implementations, the method includes transmitting the stored information of each portion of the given information, along with the information of the given primitives and occluders, for the plurality of primitives to the plurality of elements of the display ( EM) transmitting the contribution to a controller configured to calculate the contribution.

In some implementations, the method further includes masking the EM field contribution of each of the plurality of elements to a respective portion of a given primitive.

In some implementations, the method calculates the sum of the EM field contributions from the plurality of primitives to the element by excluding, for each of the plurality of elements, the EM field contributions to the element from respective parts of a given primitive. further comprising generating. Generating the sum of the EM field contributions from multiple primitives to an element is the sum of the EM field contributions from multiple primitives to an element for each part of a given primitive, without the effect of occluders. may include subtracting the EM contribution of . Generating the sum of EM field contributions to an element from a plurality of primitives may include summing EM field contributions to the element from one or more other parts of a given primitive, each part, and One or more other parts form a given primitive.

In some implementations, determining the respective parts of a given primitive that do not contribute an EM field to the element as an effect of the occluder involves connecting the element to the endpoints of the occluder and connecting the and determining that the particular parts of the given primitive enclosed by the intersection are the respective parts of the given primitive that do not contribute an EM field to the element due to the effect of the occluder. Including.

Another aspect of the present disclosure includes obtaining respective primitive data for each of a plurality of primitives corresponding to an object in three-dimensional (3D) space; and obtaining respective geometric specular information for each of the plurality of primitives. and storing respective primitive data and respective geometric specular information for each of the plurality of primitives.

In some implementations, the respective geometric specular information for each of the plurality of primitives includes a reflectance of a surface of the primitive over a viewing angle.

In some implementations, the method determines a respective EM field contribution from each of the plurality of primitives to each of the plurality of elements of the display by considering respective geometric specular information about the primitives. further including.

Another aspect of the disclosure includes obtaining graphics data including respective primitive data for a plurality of primitives corresponding to an object in three-dimensional (3D) space, and for each of the plurality of primitives in a 3D coordinate system. , determining the electromagnetic (EM) field contribution to each of the plurality of elements of the display by calculating the EM field propagation from the plurality of primitives to the element; generating a sum of EM field contributions; and, for each of the plurality of elements, transmitting a respective control signal to the element, the control signal determining the sum of the EM field contributions of the element based on the sum of the EM field contributions to the element. transmitting, the timing control signal being for modulating at least one characteristic, such that the light is caused by the modulated elements of the display to form a corresponding volumetric light field on the object; transmitting light to a display device and activating an illuminator to project light onto the display.

Another aspect of the disclosure is modifying, for each of the plurality of elements of the display, a respective control signal with a predetermined calibration value, and applying the modified respective control signal to the plurality of elements of the display. measuring a light output incident on the display; and evaluating a predetermined calibration value based on the measurement of the light output.

In some implementations, the predetermined calibration value is the same for each of the plurality of elements.

In some implementations, the method further includes converting the respective control signals for the plurality of elements with a digital-to-analog converter (DAC), wherein changing the respective control signals for the plurality of elements is performed by converting the respective control signals for the plurality of elements. It includes changing the digital signal of the control signal with a predetermined calibration value.

In some implementations, the predetermined value includes multiple bits.

In some implementations, the method further includes adjusting the predetermined calibration value based on the results of the evaluation. Adjusting the predetermined calibration value may include modifying the value of one or more of the plurality of bits. Adjusting the predetermined calibration value may include determining a combination of values of the plurality of bits based on the predetermined calibration value and another calibration value determined from a previous evaluation. can.

In some implementations, the light output includes a phase change in the light or an intensity difference between the light output and the background.

In some implementations, a control signal for each of the elements is determined based on the sum of electromagnetic (EM) field contributions to the element from multiple primitives corresponding to the object in 3D space.

Another aspect of the present disclosure is to obtain, for each of the plurality of elements of the display, a respective sum of electromagnetic (EM) field contributions from a plurality of primitives in three-dimensional (3D) space, the plurality of The primitives correspond to objects in 3D space, and each transformed EM field contribution for the element is obtained by applying the respective mathematical transformation to the sum of the respective EM field contributions for the element. determining a respective control signal based on the sum of each transformed EM field contribution for the element; and determining a respective control signal for the element based on the determined respective control signal for the element. Modulating a characteristic.

In some implementations, a method includes introducing light incident on a plurality of elements of a display, measuring a first output of light, and based on a result of measuring the first output of light. , adjusting one or more coefficients of the respective mathematical transformations of the plurality of elements. The method includes: changing the depth of the holographic pattern corresponding to the object in view of the display; measuring a second output of light; based on the first output and the second output; adjusting one or more coefficients of each mathematical transformation. The method includes: changing a plurality of primitives corresponding to a first holographic pattern to a second plurality of primitives corresponding to a second holographic pattern; and measuring a second output of light. and adjusting one or more coefficients of the respective mathematical transformations based on the first output and the second output. The first holographic pattern and the second holographic pattern can correspond to an object. The second holographic pattern may correspond to a second object that is different from the object associated with the first holographic pattern. The first output of light may be measured by an imaging sensor (eg, a point sensor or a spatially integrated sensor, or a three-dimensional sensor such as a light field sensor). The imaging sensor can be configured to use machine vision algorithms to determine what is being displayed and calculate suitability parameters. Each of the first and second holographic patterns may include a grid of dots or other fiducial elements, and the compatibility parameter may include how close the dots or other fiducial elements are together; How close the element is to the color and intensity of the intended location, how well the dot or other reference element is centered relative to the intended location, and the dot or other reference element is distorted.

In some implementations, the mathematical transformation is derived from Zernike polynomials.

In some implementations, the mathematical transformation for multiple elements varies from element to element.

In some implementations, the method includes reproducing a sample set of known colors and intensities by illuminating a display and using a colorimetric device that can be calibrated to a CIE standard observer curve to reproduce the output. The method further includes measuring the light and defining the output light of the display within a color space, such as a CIE color space. The method involves determining the deviation of a defined value of output light from a known standard value and adapting the illumination to the display or the production of output color and intensity by the display to align them. , for example, reverting to conformance with a standard or desired value.

Another aspect of the present disclosure provides determining a cell gap of a liquid crystal (LC) display based on the pitch of display elements of the LC display, and determining a cell gap of a liquid crystal (LC) display based on the cell gap and a predetermined delay of the LC display. calculating a minimum value of refraction.

In some implementations, the method further includes improving the switching speed of the LC display by keeping the birefringence of the LC mixture above a minimum value. Improving the switching speed can include at least one of increasing the dielectric anisotropy of the LC mixture and decreasing the rotational viscosity of the LC mixture.

In some implementations, the LC display includes a liquid crystal on silicon (LCOS or LCoS) device with a silicon backplane.

In some implementations, the LC display comprises a liquid crystal layer, a transparent conductive layer on top of the liquid crystal layer as a common electrode, and a plurality of metal electrodes on or electrically close to the bottom of the liquid crystal layer. a backplane, each of the plurality of metal electrodes being isolated from one another, and the backplane configured to control the voltage of each of the plurality of metal electrodes.

Another aspect of the disclosure features a display that includes a backplane and a plurality of display elements on the backplane, at least two of the plurality of display elements having different sizes.

In some implementations, the larger of the at least two display elements includes a buffer and the smaller of the at least two display elements does not include a buffer. The larger display element can be connected to the first plurality of display elements by conductive lines, and the buffer is such that the voltage is applied only to the second plurality of display elements within the first plurality of display elements. so that some of the second plurality of display elements are smaller than some of the first plurality of display elements.

In some implementations, the buffer comprises analog circuitry in the form of transistors or digital circuitry in the form of logic gates.

In some implementations, the size distribution of the plurality of display elements is substantially the same as the size of the smaller of the at least two display elements.

In some implementations, the display is configured to be a liquid crystal on silicon device.

Another aspect of the disclosure features a display that includes a backplane and a plurality of display elements on the backplane, at least two of the plurality of display elements having different shapes.

In some implementations, the backplane includes a respective circuit for each of the display elements, and each circuit for the at least two display elements has a shape that corresponds to a different shape of the at least two display elements.

In some implementations, the size distribution of the plurality of display elements is substantially the same as the predetermined size.

In some implementations, the display is configured to be a liquid crystal on silicon device.

Another aspect of the disclosure includes obtaining graphics data including respective primitive data for a plurality of primitives corresponding to an object in three-dimensional (3D) space, and for each of the plurality of primitives in a 3D coordinate system. , determining the electromagnetic (EM) field contribution to each of the plurality of elements of the display by calculating the EM field propagation from the plurality of primitives to the element; generating a sum of EM field contributions; and, for each of the plurality of elements, transmitting a respective control signal to the element, the control signal determining the sum of the EM field contributions of the element based on the sum of the EM field contributions to the element. transmitting, the timing control signal being for modulating at least one characteristic, such that the light is caused by the modulated elements of the display to form a corresponding volumetric light field on the object; transmitting light to a display device and activating an illuminator to project light onto the display.

Other embodiments of the aspects include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method. A system of one or more computers being configured to perform a particular operation or action means that the system is configured by software, firmware, hardware, or a combination thereof that causes the system to perform the operation or action during operation. This means that you have installed the . One or more computer programs configured to perform a particular operation or action means that the one or more programs, when executed by a data processing device, cause the device to perform the operation or action. It means to include.

Another aspect of the present disclosure is to be in communication with one or more processors, and to be executable by one or more processors, and when such execution is executed by one or more processors. and a non-transitory computer-readable storage medium storing instructions that cause a processor to perform one or more of the methods disclosed herein.

Another aspect of the present disclosure is capable of being executed by one or more processors, and upon such execution, causing the one or more processors to perform a method according to one or more of the methods disclosed herein. characterized by a non-transitory computer-readable storage medium storing instructions for executing.

Another aspect of the disclosure features a display including a plurality of elements and a controller coupled to the display and configured to perform one or more of the methods disclosed herein. do. The controller may include a plurality of computing units, each computing unit performing an operation on one or more of the plurality of primitives corresponding to an object in three-dimensional (3D) space. It is configured as follows. In some implementations, the controller is coupled locally to the display, and each of the computing units is coupled to one or more respective elements of the display and transmits a respective control signal to one or more respective elements of the display. and configured to transmit to each of the respective elements. Computing units can be configured to operate in parallel.

The controller may be an application specific integrated circuit (ASIC), field programmable gate array (FPGA), programmable gate array (PGA), central processing unit (CPU), graphics processing unit (GPU), or standard or custom computing cell. at least one of them. The display may include a spatial light modulator (SLM), including a digital micromirror device (DMD) or a liquid crystal on silicon (LCOS or LCoS) device. The display can be configured to be phase modulated, amplitude modulated, or phase and amplitude modulated. The controller can be coupled to the display through a memory buffer.

In some implementations, the system includes an illuminator positioned adjacent to the display and configured to emit light onto the display. The illuminator can be coupled to a controller and configured to turn on/off based on control signals from the controller.

In some cases, the illuminator is coupled to a controller through a memory buffer configured to control the amplitude or brightness of one or more light emitting elements within the illuminator. The memory buffer for the illuminator may have a smaller size than the memory buffer for the display. Some light emitting elements in the illuminator can be smaller than some elements of the display. The controller may be configured to operate one or more light emitting elements of the illuminator simultaneously or sequentially.

The illuminator can be a coherent, semi-coherent, or incoherent light source. In some implementations, the illuminator is configured to emit white light and the display is configured to diffract the white light into light having different colors. In some implementations, the illuminator includes two or more light emitting elements, each configured to emit light having a different color. The controller is configured to sequentially modulate the display with information associated with the first color during a first time period and modulate the display with information associated with the second color during a second consecutive time period. The controller may control the illuminator to emit light having a first color during a first time period and a second color during a second time period. The second light emitting element can be configured to operate sequentially to emit light having a .

In some implementations, the illuminator is positioned in front of the surface of the display and configured to emit light onto the surface of the display at an angle of incidence within a range of 0 degrees to 90 degrees; The emitted light is diffracted from the display. In some cases, the emitted light from the illuminator includes collimated light. In some cases, the emitted light from the illuminator includes divergent light. In some cases, the emitted light from the illuminator includes focused light. In some cases, the emitted light from the illuminator includes semi-collimated light.

In some implementations, the illuminator is positioned behind the back of the display and configured to emit divergent collimated light, semi-collimated light, or convergent light onto the back of the display. The emitted light is transmitted through the display and diffracted from the display from the front side of the display.

In some implementations, the illuminator includes a light source configured to emit light and a waveguide coupled to the light source and positioned adjacent the display, the waveguide comprising: The light source is configured to receive emitted light from the light source and direct the emitted light to the display. In some cases, light from a light source is coupled into the waveguide from a side section of the waveguide through an optical coupler. In some cases, the light source and waveguide are integrated in planar form and positioned on the surface of the display. The waveguide can be configured to direct light to uniformly illuminate the display.

In some cases, the waveguide is positioned on or in optical proximity to the back of the display, and light is directed and transmitted into the display from the front of the display to the display. It is diffracted from A controller can be positioned on the back side of the waveguide. In some cases, the waveguide or light guide is positioned on or optically proximate the front surface of the display, and the light is directed to be incident on the front surface of the display; It is reflected back through the front surface and diffracted.

Another aspect of the disclosure is a display including an array of elements and an integrated circuit including an array of computing units, each computing unit coupled to one or more respective elements of the display. , calculating an electromagnetic (EM) field contribution from at least one of the plurality of primitives to each of the element array, and for each of the one or more elements;
An integrated circuit configured to generate respective sums of EM field contributions from a plurality of primitives to an element.

Each of the computing units calculates a calculated EM field contribution to each of the one or more respective elements from other computing units of the array of computing units and from other primitives of the plurality of primitives. and generating, for each of the one or more respective elements, a respective sum of EM field contributions by adding the received calculated EM field contributions to the element from other primitives. Can be configured.

Each of the computing units generates, for each of the one or more respective elements, a respective control signal for modulating at least one property of the element based on a respective sum of EM field contributions to the element. It can be configured as follows.

In some implementations, the integrated circuit includes respective accumulators configured to store cumulative results of calculated EM field contributions from the plurality of primitives to each of the elements of the display. The integrated circuit may be configured to clear the accumulator at the beginning of a calculation operation. In some examples, the integrated circuit includes a respective memory buffer for each of the elements, and the integrated circuit accumulates the calculated EM field contributions from the plurality of primitives to the element for final accumulation in the respective accumulators. It may be arranged to obtain the respective sums of the EM field contributions as a result and to transfer the final accumulation result from the respective accumulators to the respective memory buffers of the elements.

In some implementations, the system includes an illumination device positioned between the integrated circuit and the display and configured to receive a control signal from the integrated circuit and to project light onto the display based on the control signal. The integrated circuit, illuminator, and display can be integrated as a single unit.

Another aspect of the disclosure includes a computing device configured to generate data including primitive data for each of a plurality of primitives corresponding to an object in three-dimensional (3D) space; The system is characterized by a system that includes, and a system that includes. The system is configured to receive graphics data from a computing device and process the graphics data to present objects in 3D space. The computing device can include an application programming interface (API) configured to create primitives with respective primitive data by rendering a computer-generated (CG) model of the object.

Another aspect of the disclosure is:
An optical device is featured that includes a first optical diffractive component, a second optical diffractive component, and a color selective polarizer between the first optical diffractive component and the second optical diffractive component. When a first light beam containing light of a first color in a first polarization state is incident on the first optical diffractive component, the first optical diffraction component When a second light beam that diffracts the colored light and includes the second colored light in a second polarization state is incident on the color-selective polarizer, the color-selective polarizer diffracts the second light beam. converting into a third beam of light comprising light of a second color in a first polarization state, the second color being different from the first color and the second polarization state being different from the first polarization state; , when the third light beam is incident on the second optical diffractive component, the second optical diffractive component diffracts the second color of light in the first polarization state, and the second optical diffractive component diffracts the second color of light in the first polarization state The diffraction efficiency with which the element diffracts the second color of light in the second polarization state is substantially greater than the diffraction efficiency with which the first optical diffractive component diffracts the first color of light in the first polarization state. small.

Another aspect of the disclosure provides a first optical diffractive component, a second optical diffractive component, and a color selective polarizer between the first optical diffractive component and the second optical diffractive component. An optical device comprising: When the first color of light is incident on the first optical diffractive component at the first angle of incidence and in the first state of polarization, the first optical diffractive component receives the first color of light. is diffracted at a first diffraction angle with a first diffraction efficiency, and the light of a second color different from the light of the first color is diffracted in a second polarization state different from the first polarization state. The first optical diffractive component diffracts the light of the second color with a diffraction efficiency that is substantially less than the first diffraction efficiency when the light is incident on the first optical diffraction component at an angle of incidence of 2. , when the second color light in the second polarization state is incident on the color-selective polarizer, the color-selective polarizer changes the polarization state of the second color light from the second polarization state to the second polarization state. a second optical diffractive component when the second color of light is incident on the second optical diffractive component at a second angle of incidence and in the first polarization state; causes light of a second color to be diffracted at a second diffraction angle with a second diffraction efficiency.

Another aspect of the present disclosure includes: i) diffracting light of a first color in a first polarization state incident at a first angle of incidence with a first diffraction efficiency at a first diffraction angle; and ii) ) diffracting light of a second color in a second polarization state incident at a second angle of incidence with a diffraction efficiency substantially less than the first diffraction efficiency; an optical diffractive component configured to rotate the polarization state of the second color of light in the second polarization state incident on the color-selective polarizer from the second polarization state to the first polarization state. a color-selective polarizer configured to diffract light of a second color in a first polarization state incident at a second angle of incidence at a second diffraction angle and with a second diffraction efficiency; two optical diffractive components, and a color selective polarizer is between the first optical diffractive component and the second optical diffractive component.

In some implementations, the second optical diffractive component transmits light of the first color in the second polarization state at the first angle of incidence with a diffraction efficiency that is substantially less than the second diffraction efficiency. It is configured to diffract the light.

In some implementations, the first optical diffractive component, the color-selective polarizer, and the second optical diffractive component are arranged such that the first color of light and the second color of light are in a second optical diffraction state. The first optical diffractive component is sequentially stacked so as to be incident on the first optical diffractive component before the component.

In some implementations, the optical device includes a third optical diffractive component and a second color-selective polarizer between the second optical diffractive component and the third optical diffractive component. Including further. The second color selective polarizer changes the polarization state of the third color light to a second polarization state when the third color light is incident on the second color selective polarizer in a second polarization state. state to a first polarization state. The third optical diffractive component has a third diffraction efficiency and a third diffraction efficiency when light of a third color is incident on the third optical diffractive component at a third angle of incidence and in a first polarization state. The third color light is diffracted at a diffraction angle of .

In some implementations, the color-selective polarizer is configured to rotate the polarization state of the first color of light from the first polarization state to the second polarization state, and the color-selective polarizer is configured to rotate the polarization state of the light of the first color from the first polarization state to the second polarization state, The polarizer is configured to rotate the polarization state of the second color light from the first polarization state to the second polarization state without rotating the polarization state of the first color light. There is.

In some implementations, the polarization state of each of the first color light and the second color light is changed from the second polarization state to the second polarization state without rotating the polarization state of the third color light. further comprising a third color selective polarizer configured to rotate to one polarization state. A third optical diffractive component is between the second color selective polarizer and the third color selective polarizer.

In some implementations, the third optical diffractive component receives light of the first color and the second color, which is incident in the second polarization state, with a diffraction efficiency that is substantially less than the third diffraction efficiency. It is configured to diffract each color of light. the first optical diffractive component is configured to diffract the incident third color light in the second diffraction state with a diffraction efficiency that is substantially less than the first diffraction efficiency; The optical diffractive component is configured to diffract each of the first color light and the third color light incident thereon in the second polarization state with a diffraction efficiency that is substantially less than the second diffraction efficiency. It is composed of

In some implementations, the second color selective polarizer includes a pair of first and second sub-polarizers. The first sub-polarizer changes the polarization state of the second color light from the first polarization state to the second polarization state without rotating the polarization state of each of the first color light and the third light. The second sub-polarizer rotates the third color of light without rotating the polarization state of each of the first color of light and the second light. The polarization state of the polarization state is rotated from the second polarization state to the first polarization state.

In some implementations, the optical device changes the polarization state of the first color light to the second color light without rotating the polarization state of each of the second color light and the third color light. a fourth color-selective polarizer configured to rotate from a polarization state to a first polarization state, wherein the first optical diffractive component is in contact with the fourth color-selective polarizer and the color-selective polarizer; and a fourth color-selective polarizer between the polarizer and the color-selective polarizer.

In some implementations, each of the first optical diffractive component, the second optical diffractive component, and the third optical diffractive component includes a respective holographic grating formed in the recording medium. The recording medium can include a photosensitive polymer. The recording medium can be optically transparent. Each holographic grating can be fixed to a recording medium.

In some implementations, each of the first optical diffractive component, the second optical diffractive component, and the third optical diffractive component includes a carrier film attached to a side of the recording medium. Each of the first optical diffractive component, the second optical diffractive component, and the third optical diffractive component may include a diffractive substrate attached to another side of the recording medium opposite the carrier film. can.

In some cases, the carrier film of the first optical diffractive component is attached to the first side of the color-selective polarizer, and the diffractive substrate of the second optical diffractive component is attached to the first side of the color-selective polarizer. the carrier film of the second optically diffractive component is attached to the first side of the second color-selective polarizer, and the carrier film of the second optically diffractive component is attached to the first side of the second color selective polarizer; A component diffractive substrate is attached to a second opposite side of the second color selective polarizer.

In some implementations, the optical device further includes a substrate, and the first optical diffractive component is between the substrate and the color-selective polarizer. In some implementations, the optical device further includes an anti-reflective coating on the surface of the substrate. In some implementations, the optical device includes a front surface and a back surface, the first color of light and the second color of light are incident on the front surface, and the optical device further includes an anti-reflective coating on the back surface. .

In some implementations, the optical device includes a plurality of optical components, including a first optical diffractive component, a color selective polarizer, and a second optical diffractive component, wherein one of the plurality of components Two adjacent optical components of are attached together through an index-matching material.

In some implementations, each of the first optical diffractive component and the second optical diffractive component includes a respective Bragg grating formed in the recording medium, and each Bragg grating has a plurality of fringe planes. includes a plurality of fringe planes having a fringe tilt angle θ _t and a fringe spacing Λ perpendicular to the fringe planes within the volume of the recording medium.

In some cases, each Bragg grating has a respective diffraction angle θ _m when the angle of incidence on the recording medium is on the Bragg angle.
,
It is constructed so that it is satisfied by Bragg's equation as follows,
where λ represents the respective wavelength of a certain color of light in vacuum, n represents the refractive index within the recording medium, θ _m represents the m-th diffraction order Bragg angle within the recording medium, θ _t represents the fringe slope within the recording medium.

In some cases, each of the first angle of incidence and the second angle of incidence is substantially the same as the On Bragg angle, and each of the first angle of diffraction and the second angle of diffraction is substantially equal to the angle of incidence of the first It is substantially the same as the Bragg angle.

In some cases, the fringe tilt angle of each Bragg grating is substantially the same as 45 degrees.

In some cases, the thickness of the recording medium is more than an order of magnitude greater than the fringe spacing. The thickness of the recording medium can be approximately 30 times greater than the fringe spacing.

In some cases, the first diffraction angle and the second diffraction angle are substantially the same as each other.

In some cases, each of the first diffraction angle and the second diffraction angle is in the range of -10 degrees to 10 degrees. Each of the first and second diffraction angles may be substantially the same as 0 degrees. Each of the first and second diffraction angles can range from -7 degrees to 7 degrees. Each of the first and second diffraction angles may be substantially the same as 6 degrees.

In some cases, the first angle of incidence and the second angle of incidence each range from 70 degrees to 90 degrees. The first angle of incidence and the second angle of incidence may be substantially the same as each other.

In some cases, the first polarization state is s-polarization and the second polarization state is p-polarization.

In some implementations, the first optical diffractive component is configured to diffract incident second color light in a second polarization state with a diffraction efficiency that is at least one order of magnitude less than the first diffraction efficiency. It is configured.

In some implementations, the color selective polarizer is configured not to rotate the polarization state of the first color of light.

In some implementations, the optical device changes the polarization state of the first color light from the second polarization state to the first polarization state without rotating the polarization state of the second color light. a second color-selective polarizer configured to rotate, the first optical diffractive component being between the second color-selective polarizer and the second color-selective polarizer; further comprising a color selective polarizer.

In some implementations, the first optical diffractive component includes a first diffractive structure, the second optical diffractive component includes a second diffractive structure, and the optical device includes a first reflective layer. and a second reflective layer, the first reflective layer being between the first diffractive structure and the second diffractive structure;
The second diffractive structure is between the first reflective layer and the second reflective layer, and the first diffractive structure is
i) diffracting first-order and zero-order first-color light incident on a first diffractive structure at a first angle of incidence, wherein the first-order is diffracted at the first diffraction angle and the zero-order is diffracted; ii) transmitting light of a second color that is incident on the first diffractive structure at a second angle of incidence; and the first reflective layer is configured to: i) completely reflect light of a first color incident on the first reflective layer at a first angle of incidence; and ii) completely reflect light of a first color incident on the first reflective layer at a first angle of incidence; The second diffractive structure is configured to transmit light of a second color that is incident on the first reflective layer, and the second diffractive structure is configured to transmit light of a second color that is incident on the second diffractive structure at a second incident angle. configured to diffract first and zero orders of second color light, the first order being diffracted at a second diffraction angle, the zero order being transmitted at a second angle of incidence, and a second reflected light. The layer is configured to completely reflect light of a second color that is incident on the second reflective layer at a second angle of incidence.

Another aspect of the disclosure provides a first optical diffractive component that includes a first diffractive structure, a second optical diffractive component that includes a second diffractive structure, a first reflective layer, and a second optical diffractive component. A reflective layer. The first reflective layer is between the first diffractive structure and the second diffractive structure, the second diffractive structure is between the first reflective layer and the second reflective layer, and the second diffractive structure is between the first reflective layer and the second reflective layer. When light of color is incident on the first diffraction structure at a first angle of incidence, the first diffraction structure diffracts the first and zero orders of light of the first color, and the first order is incident at the first angle of incidence. When the zero order is diffracted at a first angle of incidence and the zeroth order is transmitted at a first angle of incidence, the first grating is When the first color light is incident on the first reflective layer at the first angle of incidence, the first reflective layer transmits the first color light. For complete reflection, when the light of the second color is incident on the first reflective layer at the second angle of incidence, the reflective layer transmits the light of the second color at the second angle of incidence, and the light of the second color is incident on the first reflective layer at the second angle of incidence. When light of color is incident on the second diffraction structure at a second angle of incidence, the second diffraction structure diffracts the first and zero orders of light of the second color, and the first order diffracts the second color light. When the light of the second color is incident on the second reflective layer at the second angle of incidence and the zeroth order is transmitted at a second angle of incidence, the second reflective layer completely reflects the color of light.

Another aspect of the present disclosure is a first diffractive structure, the first diffractive structure comprising: i) diffracting first-order and zero-order first color light that is incident on the first diffractive structure at a first angle of incidence; ii) the first order is diffracted at a first diffraction angle and the zero order is transmitted at a first angle of incidence; and ii) the first order is incident on the first diffractive structure at a second angle of incidence. a first optical diffractive component comprising a first diffractive structure configured to transmit light of a second color; and i) incident on the first reflective layer at a first angle of incidence. and ii) transmitting a second color of light incident on the first reflective layer at a second angle of incidence. a first reflective layer and a second diffractive structure, diffracting first-order and zero-order second color light that is incident on the second diffractive structure at a second angle of incidence; a second optical diffractive structure configured to diffract the first order at a second diffraction angle and the zero order to be transmitted at a second angle of incidence; a second reflective layer configured to completely reflect light of a second color incident on the second reflective layer at a second angle of incidence, the first reflective layer comprising: An optical device is featured between a first diffractive structure and a second diffractive structure, the second diffractive structure being between a first reflective layer and a second reflective layer.

Another aspect of the present disclosure provides a first optical diffractive component that includes a first diffractive structure configured to diffract light of a first color having a first angle of incidence at a first angle of diffraction. and a second optical diffractive component comprising a second diffractive structure configured to diffract light of a second color having a second angle of incidence at a second angle of diffraction; a first reflective layer configured to fully reflect light of a first color having an angle and transmit light of a second color having a second angle of incidence; a second reflective layer configured to completely reflect light of a second color having a second angle of incidence, the first reflective layer comprising a first diffractive structure and a second diffractive structure; and a second diffractive structure between the first reflective layer and the second reflective layer.

In some implementations, the optical device further includes a color selective polarizer between the first diffractive structure and the second diffractive structure. The first diffractive structure is configured to i) diffract light of a first color in a first polarization state incident at a first angle of incidence with a first diffraction efficiency; and ii) at a second angle of incidence. The incident light of the second color in the second polarization state is
diffraction with a diffraction efficiency substantially lower than the first diffraction efficiency. Color-selective polarizers are
the polarization state of the light of the second color in the second polarization state incident on the color selective polarizer;
It can be configured to rotate from the second polarization state to the first polarization state. The second diffractive structure can be configured to diffract light of a second color in a first polarization state incident at a second angle of incidence with a second diffraction efficiency.

In some implementations, the optical device further includes a side surface and a light absorber attached to the side surface and configured to absorb fully reflected light of the first color and the second color. .

In some implementations, the first reflective layer is configured to have a lower refractive index than the layer of the first optical diffractive component immediately adjacent to the first reflective layer, and thus: Light of a first color having a first angle of incidence is transmitted through the first reflective layer and the first optical diffractive component without completely reflecting light of a second color having a second angle of incidence. completely reflected by the interface between the layers.

In some implementations, the first optical diffractive component includes a first carrier film and a first diffractive substrate attached to opposite sides of the first diffractive structure, and the first carrier film is attached to opposite sides of the first diffractive structure. The first carrier film can include a first reflective layer closer to the second diffractive structure than the first diffractive substrate.

In some implementations, the second optical diffractive component includes a second carrier film and a second diffractive substrate attached to opposite sides of the second diffractive structure, and the second diffractive substrate is attached to opposite sides of the second diffractive structure. The second reflective layer is closer to the first diffractive structure than the second carrier film, and the second reflective layer is attached to the second carrier film.

In some implementations, the optical device is configured to diffract first-order and zero-order third color light that is incident on the third diffractive structure at a third angle of incidence. further comprising a third optical diffractive component comprising a structure, the first order is diffracted at a third diffraction angle, the zero order is transmitted at a third angle of incidence, and the second reflective layer is configured to between the structure and the third diffractive structure.

In some cases, each of the first reflective layer and the second reflective layer is configured to transmit light of a third color that is incident at a third angle of incidence.

In some implementations, the optical device further includes a third reflective layer configured to completely reflect light of a third color that is incident on the third reflective layer at a third angle of incidence. ,
A third diffractive structure is between the second reflective layer and the third reflective layer.

In some implementations, the second optical diffractive component includes a second diffractive substrate and a second carrier film disposed on opposite sides of the second diffractive structure, and the third optical diffractive component includes: , a third carrier film and a third diffractive substrate positioned on either side of the third diffractive structure, the second reflective layer being between the second carrier film and the third carrier film. .

In some implementations, the first diffractive structure and the second diffractive structure each include a respective holographic grating formed in the recording medium. The recording medium can include a photosensitive polymer. The recording medium can be optically transparent.

In some implementations, each of the first optical diffractive component and the second optical diffractive component includes a respective Bragg grating formed in the recording medium, and each Bragg grating covers a volume of the recording medium. a plurality of fringe planes having a fringe inclination angle θ _t and a fringe spacing Λ perpendicular to the fringe planes within.

In some implementations, each Bragg grating has a respective diffraction angle θ _m when the angle of incidence on the recording medium is on the Bragg angle.
,
It is constructed so that it is satisfied by Bragg's equation as follows,
where λ represents the respective wavelength of a certain color of light in vacuum, n represents the refractive index within the recording medium, θ _m represents the m-th diffraction order Bragg angle within the recording medium, θ _t represents the fringe slope within the recording medium.

Each of the first angle of incidence and the second angle of incidence may be substantially the same as a respective On Bragg angle, and each of the first angle of diffraction and the second angle of diffraction may be substantially the same as a respective primary Bragg angle. may be substantially the same.

In some implementations, the thickness of the recording medium is more than an order of magnitude greater than the fringe spacing. The thickness of the recording medium can be approximately 30 times greater than the fringe spacing.

In some cases, the first diffraction angle and the second diffraction angle are substantially the same as each other. In some examples, the first diffraction angle and the second diffraction angle are each in a range of -10 degrees to 10 degrees. In some examples, each of the first diffraction angle and the second diffraction angle is substantially the same as 0 degrees. In some examples, each of the first diffraction angle and the second diffraction angle is substantially the same as 6 degrees.

In some cases, the first angle of incidence is different than the second angle of incidence. In some cases, the first color of light has a smaller (or shorter) wavelength than the second color of light, and the first angle of incidence of the first color of light is smaller than the second color of light. greater than (or longer than) the second angle of incidence of the colored light. In some cases, the first angle of incidence and the second angle of incidence each range from 70 degrees to 90 degrees.

In some implementations, the optical device includes a plurality of components including a first optical diffractive component and a second optical diffractive component, and two adjacent components of the plurality of components include: They are attached together by an interlayer comprising at least one of a refractive index matching material, an OCA, a UV or heat cured optical adhesive, or an optical contact material.

In some implementations, the second reflective layer includes an intermediate layer.

In some implementations, the optical device further includes a substrate having a back surface attached to the front surface of the first optical diffractive component. The substrate can include a side surface that is angled relative to the back surface and configured to receive a plurality of different colors of light at the side surface. The angle between the side and back sides of the substrate can be 90 degrees or more. The substrate can be configured such that a plurality of different colors of light are incident on the sides at an angle of incidence that is substantially the same as 0 degrees. In some cases, the substrate is wedge-shaped and includes an angled front surface and the angle between the front surface and the side surface is less than 90 degrees.

Another aspect of the disclosure features a system that includes an illuminator configured to provide a plurality of different colors of light and any one of the optical devices described herein. The optical device is disposed adjacent to the illuminator and is configured to receive a plurality of different colors of light from the illuminator and diffract a plurality of different colors of light. There is.

In some implementations, the optical device is configured to diffract a plurality of different colors of light at respective diffraction angles that are substantially the same as each other.

In some examples, each of the respective diffraction angles ranges from -10 degrees to 10 degrees.

In some implementations, the system further includes a controller coupled to the illuminator and configured to control the illuminator to provide each of the plurality of different colors.

In some implementations, the system further includes a display that includes multiple display elements, and the optical device is configured to diffract multiple colors of light onto the display.

In some implementations, the controller is coupled to the display and configured to transmit a respective control signal to each of the plurality of display elements for modulation of at least one characteristic of the display element. .

In some implementations, the controller obtains graphics data including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space; and for each of the plurality of primitives, a plurality of displays of the display. determining an electromagnetic (EM) field contribution to each of the plurality of display elements; for each of the plurality of display elements, generating a sum of EM field contributions from the plurality of primitives to the display element; and for each of the plurality of display elements. and generating respective control signals based on the sum of the EM field contributions to the display element.

Another aspect of the disclosure is a system including a display including a plurality of display elements and any one of the optical devices described herein, the optical device directing a plurality of different colors of light to the display. The system is configured to diffract the image.

In some implementations, the optical device and display are arranged along a direction. The optical device includes a front surface and a back surface along the direction, and the display includes a front surface and a back surface along the direction, and the front surface of the display is spaced apart from the back surface of the optical device.

In some implementations, the front surface of the display is separated from the back surface of the optical device by a gap. At least one of the front side of the display or the back side of the optical device can be treated with an anti-reflection coating.

In some implementations, the system further includes a transparent protective layer on the back side of the optical device.

In some implementations, the front side of the display and the back side of the optical device are attached together by an interlayer. The interlayer has a refractive index of the layers of the optical device such that each of the multiple colors of light transmitted by the optical device at the zero order is completely reflected at the interface between the interlayer and the layers of the optical device. It can be configured to have a refractive index lower than that.

In some implementations, the system further includes a cover (eg, a cover glass) on the front surface of the display, and the optical device is formed within the cover glass.

In some implementations, the optical device is configured to receive multiple colors of light in front of the optical device.

In some implementations, the optical device includes a substrate in front of the optical device and is configured to receive multiple colors of light on a side of the substrate that is angled relative to a back surface of the substrate. .

In some implementations, the optical device includes at least one diffraction grating supported by the substrate and configured to diffract a plurality of different colors of light toward the display.

In some implementations, the substrate includes a container filled with a liquid that has a lower refractive index than the recording medium of the grating.

In some implementations, the substrate is wedge-shaped and includes a sloped front surface. The angle between the front surface and the side surface may be less than 90 degrees.

In some implementations, the optical device receives different portions of the plurality of different colors of light along different optical paths within the substrate and diffracts the different portions to illuminate different corresponding areas of the display. It is configured to do that and. The different areas may include two or more of a bottom area, a top area, a left area, and a right area of the display. Different portions of light of different colors can be provided by different corresponding illuminators. The optical device may be configured to receive different portions of light of a plurality of different colors from different corresponding sides of the substrate.

In some examples, the optical device receives a first portion of the plurality of different colors of light from a first side of the substrate to a back side of the optical device, and diffracts the first portion to generate a first portion of the display. receiving a second portion of the plurality of differently colored light from a second side of the substrate to a front surface of the optical device, the second portion being directed toward a back surface of the optical device; and is configured to reflect back and diffract a second portion to illuminate a second area of the display. The first side and the second side may be the same side. A second portion of the plurality of different colors of light may be reflected by total internal reflection or a reflective grating within the optical device. The substrate can also include a partially reflective surface configured to separate the input light into a first portion and a second portion.

In some implementations, the optical device includes at least one diffraction grating positioned on the back side of the optical device. A diffraction grating can include different sub-regions with different corresponding diffraction efficiencies. The diffraction grating diffracts a first portion of the plurality of different colors of light incident on the first sub-region of the diffraction grating to illuminate the first region of the display and further back against the back surface of the optical device. reflecting a second portion of the plurality of different colors of light that is reflected by the grating and incident on a second sub-region of the diffraction grating to a front surface of the optical device and diffracting the second portion; and irradiating a second different area of the area.

In some examples, the diffraction grating is configured such that the first diffracted portion and the second diffracted portion on the first and second regions of the display have substantially the same optical power. It is configured. The first region and the second region of the display have different reflectivities associated with a first different diffraction efficiency and a second different diffraction efficiency of the first sub-region and the second sub-region of the diffraction grating. can have.

In some implementations, the diffraction grating includes multiple subregions that are tiled together. Sub-regions can be tiled along the horizontal direction.

In some cases, the edges of different sub-regions are configured to abut each other in an optically seamless manner. The different sub-regions may be formed by including one or more edge-defining elements in the optical path of at least one of the recording beam or the object beam when recording each sub-region on the recording medium; The edge-defining elements described above may include square apertures, rectangular apertures, or planar tile apertures.

In some cases, two adjacent sub-regions of the grating abut a gap. The display can include a plurality of tiled display devices, with gaps between adjacent sub-regions of the diffraction grating aligned with gaps between adjacent tiled display devices of the display.

In some cases, two adjacent different sub-regions have an overlap.

In some implementations, the diffraction grating is mechanically formed by using embossed, nanoimprinted, or self-assembled structures.

In some implementations, the display has a width along a horizontal direction and a height along a vertical direction, where both the horizontal and vertical directions are perpendicular to the direction, and the aspect ratio between the width and the height. The ratio can be greater than 16:9.

In some implementations, the optical device is configured to diffract a plurality of different colors of light at respective diffraction angles that are substantially the same as each other. In some examples, each of the respective diffraction angles ranges from -10 degrees to 10 degrees.

In some implementations, the display is configured to diffract the diffracted colored light back through the optical device.

In some implementations, an area of the optical device covers an area of the display.

In some implementations, the system further includes an illuminator positioned adjacent to the optical device and configured to provide multiple colors of light to the optical device. The illuminator can include a plurality of light emitting elements, each configured to emit a respective color of light.

In some implementations, the centers of the beams from multiple light emitting elements may be offset with respect to each other. The illuminator can be configured to provide a light beam with an elliptical beam profile or a rectangular beam profile. The illuminator can be configured to provide a light beam with a particular polarization orientation. The illuminator may include one or more optical components configured to independently control the ellipticity and polarization orientation of each of the plurality of different colors of light.

In some implementations, the illuminator includes one or more optical components configured to control the uniformity of the plurality of different colors of light. The one or more optical components include an apodizing optical element or a profile converter.

In some implementations, the system includes one or more anamorphic optical elements or one or more cylindrical optical elements configured to increase the width of light of a plurality of different colors.

In some implementations, the system includes a prismatic element between the illuminator and the optical device, the prismatic element configured to receive light of a plurality of different colors from an input surface of the prismatic element; one or more expansion gratings adjacent an exit face of the element, each of the one or more expansion gratings configured to expand a beam profile of light of a different corresponding color by a factor in at least one dimension; and one or more expanded lattices.

In some implementations, the system can further include one or more reflectors downstream of the one or more expanded gratings, each of the one or more reflectors directing a respective color of light to the optical device. It is designed to reflect. The tilt angle of each of the one or more reflectors may be independently adjustable to cause uniformity of diffraction from the optical device to the display.

The system can further include at least one of a color sensor or a brightness sensor configured to detect one or more optical properties of the holographic light field formed by the system, and one or more reflectors. The tilt angle of is adjustable based on the detected optical properties of the holographic light field. The one or more optical properties may include brightness uniformity, color uniformity, or white point.

In some implementations, one or more reflectors are adjustable to compensate for changes in alignment of components of the system.

In some implementations, the optical distance between the one or more reflectors and the optical device is such that each of the plurality of different colors of light corresponds to each other without transmission through one or more other reflectors. It is configured to be reflected by a reflector.

In some implementations, the one or more reflectors are configured such that light emitted by each of the one or more reflectors comes from substantially different directions.

In some implementations, the angle between the prism element and the substrate of the optical device is adjustable to tilt the position of the holographic light field formed by the system.

In some implementations, the one or more expanding gratings are configured to at least partially collimate the plurality of different colors of light in one or two lateral directions.

In some implementations, the system further includes a controller coupled to the illuminator and configured to control the illuminator to provide each of the plurality of colors of light. A controller may be coupled to the display and configured to transmit a respective control signal to each of the plurality of display elements for modulation of at least one characteristic of the display element.

In some implementations, the controller obtains graphics data including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space; and for each of the plurality of primitives, a plurality of displays of the display. determining an electromagnetic (EM) field contribution to each of the plurality of display elements; for each of the plurality of display elements, generating a sum of EM field contributions from the plurality of primitives to the display element; and for each of the plurality of display elements. and generating respective control signals based on the sum of the EM field contributions to the display element.

In some implementations, the controller sequentially modulates the display with information associated with the plurality of colors of light for a series of time periods, and each of the plurality of colors of light is diffracted onto the display by an optical device. of a plurality of colors during each of a series of time periods, and reflected by the modulated display elements of the display to form a three-dimensional light field with each color corresponding to an object within each time period. and controlling the illuminator to sequentially emit each of the lights to the optical device.

In some implementations, the controller causes the three-dimensional light field of each color to be completely in front of the display, completely behind the display, or partially in front of the display, and partially behind the display. is configured to modulate the display so that it appears.

In some cases, the display includes a spatial light modulator (SLM), including a digital micromirror device (DMD) or a liquid crystal on silicon (LCOS) device.

In some implementations, the system further includes an optical polarizer disposed between the display and the optical device, the optical polarizer configured to change the polarization state of the plurality of different colors of light. There is.

In some implementations, the optical device is configured to diffract light that includes a plurality of different colors of light relative to a display that is configured to diffract a portion of the light that illuminates the display element. Contains an optical diffractive component.

In some implementations, the optical device transmits a portion of the light to form a holographic scene and redirects the display zero-order light away from the holographic scene in three-dimensional (3D) space. The display further includes an optical redirection component configured to perform the following steps, wherein the display zero order light includes reflected light from the display.

In some implementations, the optical redirecting component includes a plurality of redirecting holographic gratings for displaying zero-order light of a plurality of different colors of light, each of the plurality of redirecting holographic gratings displaying a plurality of different colors of light. The display of each color of light is configured to diffract the zero-order light at a respective diffraction angle toward a respective direction in 3D space.

In some implementations, the optical diffractive component emits light of a plurality of different colors such that the optical diffractive component redirects display zero-order light reflected from the display away from the holographic scene. It is configured to diffract and illuminate the display at an angle of about 0 ^° .

In some implementations, the amount of display zero-order light in the holographic scene with suppression of the optical diffraction component and the optical redirection component and the amount of display zero-order light in the holographic scene without suppression. The ratio is less than 2%.

In some implementations, the optical redirection component includes a one-dimensional suppression grating, the holographic scene includes a band corresponding to suppression of display zero-order light, and the system provides a system that includes a one-dimensional suppression grating in which the band is outside of the viewer's field of view. It can be configured as follows.

Another aspect of the disclosure provides a display including a plurality of display elements, an optical device disposed adjacent to the display and configured to diffract light with respect to the display, and an optical device coupled to the display and configured to diffract light with respect to the display. obtaining graphics data including respective primitive data for a plurality of primitives corresponding to objects in a source space; and for each of the plurality of primitives, electromagnetic (EM) data from the primitive to a display element in a three-dimensional coordinate system; determining the EM field contribution to each of the plurality of display elements of the display by calculating field propagation and generating, for each of the plurality of display elements, the sum of the EM field contributions from the plurality of primitives to the display element; and transmitting, for each of the plurality of display elements, a respective control signal based on the sum of the EM field contributions to the display element for modulation of at least one characteristic of the display element. and a controller configured to.

In some implementations, the optical device can include any one of the optical devices that include at least one color selective polarizer as described herein.

In some implementations, the optical device includes any one of the optical devices that include at least one reflective layer as described herein.

In some implementations, the optical device includes a holographic grating formed in a recording medium.

In some implementations, the optical device includes a plurality of holographic gratings formed on a recording medium, each of the plurality of holographic gratings having a respective angle of incidence with respect to the display. is configured to diffract light with a

In some implementations, an optical device is placed in front of the display, and the display is configured to diffract the diffracted light through the optical device to form a three-dimensional light field corresponding to the object. has been done.

In some implementations, the system further includes an illuminator positioned adjacent to the optical device and configured to provide light to the optical device.

In some implementations, the controller sequentially modulates the display with information associated with a plurality of colors corresponding to the plurality of colors of light for a series of time periods, and wherein each of the plurality of colors of light is connected to the optical device. during each of a series of time periods so as to be diffracted against the display by and reflected by the modulated display elements of the display to form a three-dimensional light field with a respective color corresponding to the object within each time period. and controlling the illuminator to sequentially emit each of the plurality of colors of light to the optical device.

Another aspect of the disclosure features a method that includes making any one of the optical devices described herein.

Another aspect of the disclosure includes forming a first optical diffractive component, forming a second optical diffractive component, and forming a first optical diffractive component and a second optical diffractive component. disposing a color-selective polarizer between the color-selective polarizer and the optical device.

In some implementations, forming the first optical diffractive component includes forming a first diffractive structure in the recording medium.

In some implementations, forming a first diffractive structure on the recording medium includes forming a first recording object beam on the recording medium at a first recording object angle and a first recording object beam at a first recording reference angle. recording a first holographic grating on a recording medium by irradiating a first recording reference beam, the first recording object beam and the first recording reference beam having the same wavelength and the same first recording reference beam; It has a polarization state of .

In some examples, the first color of light includes a wider or the same wavelength range as the first recording reference beam or the first recording object beam. In some examples, the first recording reference beam corresponds to a different color than the first color of the first color of light.

In some examples, the first angle of incidence of the first color light is substantially the same as the first recording reference angle, and the first diffraction angle is substantially the same as the first recording object angle. is the same as

In some examples, the first recording reference angle is in a range of 70 degrees to 90 degrees. In some examples, the first recording reference angle is in a range of 80 degrees to 90 degrees. In some examples, the angle of the first recording object ranges from -10 degrees to 10 degrees. In some examples, the angle of the first recording object is substantially equal to 6 degrees. In some examples, the angle of the first recording object is substantially the same as 0 degrees. In some examples, the sum of the first recording reference angle and the first recording object angle is substantially equal to 90 degrees.

In some implementations, the thickness of the recording medium is more than an order of magnitude greater than the wavelength of the first recording object beam. The thickness of the recording medium may be approximately 30 times greater than the wavelength of the first recording object beam.

In some implementations, forming the first diffractive structure on the recording medium includes securing the first diffractive structure to the recording medium.

In some implementations, the recording medium is between the carrier film and the diffractive substrate.

In some embodiments, the first diffraction angle and the second diffraction angle are substantially the same as each other. In some examples, the first angle of incidence and the second angle of incidence are substantially the same as each other.

In some implementations, disposing a color-selective polarizer between the first optical diffractive component and the second optical diffractive component may cause light of the first color and light of the second color to be polarized. is incident on the first optical diffractive component before the second optical diffractive component. including doing.

In some implementations, sequentially stacking the first optical diffractive component, the color selective polarizer, and the second optical diffractive component includes the first optical diffractive component, the color selective polarizer, and sequentially positioning a second optical diffraction component on the substrate in front of the first optical diffraction component.

In some implementations, sequentially stacking the first optical diffractive component, the color-selective polarizer, and the second optical diffractive component includes passing the color-selective polarizer through the first intermediate layer. , attaching the second optical diffractive component to the color-selective polarizer through the second interlayer, and attaching the second optical diffractive component to the color-selective polarizer through the second interlayer. Each of the two intermediate layers includes a respective refractive index matching material.

In some implementations, the method is configured to diffract light of a third color having a first polarization state and a third angle of incidence at a third diffraction angle with a third diffraction efficiency. forming a third optical diffractive component; and disposing a second color-selective polarizer between the second optical diffractive component and the third optical diffractive component; The two color-selective polarizers further include: configured and arranged to rotate the polarization state of the third color light from the second polarization state to the first polarization state.

In some implementations, the color-selective polarizer is configured to rotate the polarization state of the first color of light from the first polarization state to the second polarization state, and the color-selective polarizer is configured to rotate the polarization state of the light of the first color from the first polarization state to the second polarization state, The polarizer is configured to rotate the polarization state of the second color light from the first polarization state to the second polarization state without rotating the polarization state of the first color light. There is.

In some implementations, the method includes a third color-selective polarizer in series with a third optical diffractive component, a third color-selective polarizer in series with a third optical diffractive component, and a third color-selective polarizer in series with the third optical diffractive component. and a color-selective polarizer of the third color, the third color-selective polarizer being between the first color-selective polarizer and the third color-selective polarizer without rotation of the polarization state of the third color of light. The polarization state of each of the color light and the second color light is configured to be rotated from the second polarization state to the first polarization state.

In some implementations, the method includes a fourth color-selective polarizer in front of the first optical diffractive component, and a fourth color-selective polarizer in front of the first optical diffractive component. and a fourth color-selective polarizer that does not involve rotation of the polarization state of each of the second color light and the third color light. The polarization state of the first color light is rotated from the second polarization state to the first polarization state.

In some implementations, the first polarization state is s-polarization and the second polarization state is p-polarization.

Another aspect of the present disclosure is a method of making any one of an optical device that includes at least one reflective layer, the method comprising: forming a first optical diffractive component that includes a first diffractive structure; forming a second optical diffractive component including a second diffractive structure; and disposing a first reflective layer between the first diffractive structure and the second diffractive structure; arranging a diffractive structure that is continuous with the first diffractive structure along a certain direction; and arranging a second reflective layer that is continuous with the second diffractive structure along a certain direction. The method includes.

In some implementations, the method further includes forming a light absorber on a side of the optical device, the light absorber absorbing fully reflected light of the first color and the second color. is configured to do so.

In some implementations, the first reflective layer is configured to have a lower refractive index than the layer of the first optical diffractive component immediately adjacent to the first reflective layer, and thus: Light of a first color having a first angle of incidence is transmitted through the first reflective layer and the first optical diffractive component without completely reflecting light of a second color having a second angle of incidence. completely reflected by the interface between the layers.

In some implementations, the method includes forming a third optical diffractive component that includes a third diffractive structure configured to diffract light of a third color having a third angle of incidence. further comprising disposing a second reflective layer sequentially to the second diffractive structure along the direction, a second reflective layer is disposed between the second diffractive structure and the third diffractive structure along the direction. Including placing layers. Each of the first reflective layer and the second reflective layer can be configured to transmit a third color of light having a third angle of incidence.

In some implementations, the method further includes disposing a third reflective layer sequentially to the third diffractive structure along the direction, the third reflective layer having a third angle of incidence. It is configured to completely reflect the third color of light.

In some implementations, each of the first optical diffractive component, the second optical diffractive component, and the third optical diffractive component includes a respective carrier film and a respective diffractive substrate; The reflective layer includes a first carrier film of a first optical diffractive component. Positioning the first reflective layer between the first diffractive structure and the second diffractive structure allows the first interlayer to direct the second diffractive substrate of the second optical diffractive component to the first optical diffractive structure. Attaching the diffractive component to the first carrier film may include attaching the diffractive component to the first carrier film. arranging the second reflective layer between the second and third diffractive structures along the direction of disposing the second carrier film of the second optical diffractive component by the second intermediate layer; The method may include attaching a third optical diffractive component to a third carrier film. The second reflective layer can include a second intermediate layer. A third reflective layer can be attached to the third diffractive substrate of the third optical diffractive component.

In some implementations, the method includes positioning a first optical diffractive component on a substrate in front of the first optical diffractive component along the direction, the substrate including a front surface and a back surface. , further comprising locating.

In some implementations, placing the first optical diffractive component on the substrate includes attaching the front surface of the first optical diffractive component to the back surface of the substrate through an index matching material.

In some implementations, the substrate includes a side surface that is angled relative to a back surface of the substrate, and the substrate is configured to receive a plurality of different colors of light at the side surface. The substrate can be configured such that a plurality of different colors of light are incident on the sides at an angle of incidence that is substantially the same as 0 degrees.

In some implementations, forming a first optical diffractive component that includes a first diffractive structure includes forming a first diffractive structure in a recording medium.

In some implementations, forming a first diffractive structure in a recording medium includes forming a first recording object beam at a first recording object angle and a first recording reference beam at a first recording reference angle. recording a first holographic grating in the recording medium by injecting a first recording object beam and a first recording reference beam having the same wavelength and the same polarization state.

In some implementations, the first color of light includes a wavelength range that is wider than or the same as the first recording reference beam.

In some implementations, the first recording reference beam corresponds to a different color than the first color of the first color of light.

In some implementations, the first angle of incidence of the first color of light is substantially the same as the first recording reference angle, and the first diffraction angle is the angle of the first recording object. are substantially the same.

In some examples, the first recording reference angle is in a range of 70 degrees to 90 degrees. In some examples, the first recording reference angle is in a range of 70 degrees to 80 degrees. In some examples, the angle of the first recording object ranges from -10 degrees to 10 degrees.

In some implementations, the thickness of the recording medium is more than an order of magnitude greater than the wavelength of the first recording object beam. The thickness of the recording medium may be approximately 30 times greater than the wavelength of the first recording object beam.

In some implementations, forming the first diffractive structure on the recording medium includes securing the first diffractive structure to the recording medium.

In some implementations, the first angle of incidence is different than the second angle of incidence. In some examples, the first color of light has a smaller (or shorter) wavelength than the second color of light, and the first angle of incidence is larger (or longer) than the second angle of incidence. ).

Another aspect of the disclosure provides forming any one of the optical devices described herein by any one of the methods described above, and forming an optical device and a display including a plurality of display elements. arranging the device to be configured to diffract a plurality of different colors of light to the display.

In some implementations, positioning the optical device and the display includes spacing the back of the optical device from the front of the display by a gap.

In some implementations, the method further includes forming an anti-reflective coating on at least one of the front side of the display or the back side of the optical device.

In some implementations, placing the optical device and display includes attaching the back side of the optical device onto the front side of the display through an intermediate layer.

In some cases, the interlayer is optically transparent, such that each of the multiple different colors of light transmitted by the optical device at the zero order is completely reflected at the interface between the interlayer and the layer of the optical device. It is configured to have a refractive index that is lower than the refractive index of the layers of the device.

In some implementations, the optical device is configured to diffract a plurality of different colors of light at respective diffraction angles that are substantially the same as each other.

In some examples, each of the respective diffraction angles ranges from -10 degrees to 10 degrees.

In some implementations, the display is configured to diffract the diffracted colored light back through the optical device.

In some implementations, an area of the optical device covers an area of the display.

In some implementations, the optical device includes a substrate in front of the optical device and is configured to receive light of a plurality of different colors at a side of the substrate that is angled relative to a back surface of the substrate. There is.

Another aspect of the disclosure features a method that includes using an optical device to convert an incident beam that includes a plurality of different colors of light into individually diffracted colors of light. The optical device can be any one of the optical devices as described herein.

Another aspect of the present disclosure provides for at least one timed optical device to convert a plurality of different colors of light into individually diffracted colored light to illuminate a display including a plurality of display elements. transmitting a control signal to an illuminator to operate the illuminator to emit light of a plurality of different colors to an optical device, the optical device being any of the optical devices described herein; a display such that the individually diffracted colored light is reflected by the modulated display elements to form a multicolored three-dimensional light field corresponding to a respective control signal. transmitting at least one respective control signal for each of the plurality of display elements to modulate the display element.

In some implementations, a method includes obtaining graphics data including respective primitive data for a plurality of primitives corresponding to an object in three-dimensional space, and for each of the plurality of primitives in a three-dimensional coordinate system. , determining the EM field contribution to each of the plurality of display elements of the display by calculating the electromagnetic (EM) field propagation from the plurality of display elements from the plurality of display elements for each of the plurality of display elements; generating a sum of EM field contributions to the display element and, for each of the plurality of display elements, for modulating at least one characteristic of the display element, respectively based on the sum of the EM field contributions to the display element; and generating a control signal for the multicolor three-dimensional light field corresponding to the object.

In some implementations, the method includes sequentially modulating a display with information associated with a plurality of different colors for a series of time periods, each of the plurality of different colors of light being diffracted onto the display by an optical device. of a plurality of colors within each of a series of time periods, and reflected by the modulated display elements of the display to form a three-dimensional light field with each color corresponding to an object within each time period. controlling the illuminator to sequentially emit each of the lights to the optical device.

In some implementations, the plurality of different colors of light are diffracted by the optical device at substantially the same diffraction angle with respect to the display. In some examples, the diffraction angle is in the range of -10 degrees to 10 degrees.

In some implementations, the illuminator and optical device are configured such that a plurality of different colors of light are incident on the first optical diffractive component of the optical device at respective angles of incidence. In some examples, each angle of incidence is different from each other. In some examples, each angle of incidence is substantially the same as each other. In some examples, each of the respective angles of incidence range from 70 degrees to 90 degrees.

Another aspect of the disclosure features an optical device that includes at least two optical diffractive components and at least one color-selective polarizer, wherein when light of different colors is incident on the optical device. , an optical device is configured to separate individual colors of light of different colors while suppressing crosstalk between the different colors.

In some implementations, the optical device is configured such that each of the optical diffractive components diffracts a respective color of light when the different colors of light are incident on the optical device.

In some implementations, the optical device is configured such that in an output light beam diffracted by the optical device, the power of light of a particular one of the different colors is greater than the power of light of one or more other colors of the different colors. The power is at least an order of magnitude higher than that of

In some implementations, the at least one color-selective polarizer is configured such that light of a particular color of the different colors is incident on a respective one of the optical diffractive components in a first polarization state; of the different colors such that light of one or more other colors of the different colors is incident on a respective one of the optical diffractive components in a second state of polarization that is different from the first state of polarization. is configured to rotate the polarization state of at least one color of light.

Another aspect of the disclosure features an optical device that includes at least two optical diffractive components and at least one reflective layer, wherein when light of different colors is incident on the optical device, the optical device is configured to separate the individual colored lights of the different colors while suppressing crosstalk between the different colors, and the at least one reflective layer is configured to separate the individual colored lights of the different colors while suppressing crosstalk between the different colors. Configured for internal reflection.

In some implementations, the optical device is configured such that the output light beam diffracted by the optical device has a specific color after the different colors without crosstalk from one or more of the other colors. It is configured to contain only the light of

In some implementations, the at least one reflective layer completely reflects zero-order light of a particular color of the different colors transmitted by each one of the optical diffractive components, while is configured to transmit one or more other colors.

In some implementations, the optical device is configured such that each of the optical diffractive components diffracts a respective color of light when the different colors of light are incident on the optical device.

Another aspect of the disclosure features a display and any one of the optical devices described herein, the optical device configured to diffract a plurality of different colors of light with respect to the display. There is.

Another aspect of the disclosure features an illuminator configured to provide light of a plurality of different colors and any one of the optical devices described herein, the optical device configured to provide light of a plurality of different colors. The illuminator is configured to diffract colored light from the illuminator.

Another aspect of the disclosure features a system that includes a display and an optical device that includes one or more transmissive diffractive structures to diffract light to the display.

In some implementations, the display is a reflective display configured to diffract light through an optical device. In some implementations, the system further includes an illuminator configured to provide light to the optical device, the illuminator disposed in front of the transmission diffractive structure of the optical device.

In some implementations, the display is a transmissive display configured to diffract light forward through an optical device. In some implementations, the system further includes an illuminator configured to provide light to the optical device, the illuminator positioned behind the transmission diffractive structure of the optical device.

In some implementations, each of the one or more transmissive diffractive structures is configured to diffract a respective one of a plurality of different colors.

In some implementations, the optical device further includes one or more reflective diffractive structures, each of the one or more transmissive diffractive structures and the one or more reflective diffractive structures displaying a respective color of a plurality of different colors. It is configured to cause diffraction.

Another aspect of the disclosure features a system that includes a display and an optical device that includes one or more reflective diffractive structures to diffract light to the display.

In some implementations, the display is a reflective display configured to diffract light through an optical device. In some implementations, the system further includes an illuminator configured to provide light to the optical device, the illuminator positioned behind the reflective diffractive structure of the optical device.

In some implementations, the display is a transmissive display configured to diffract light forward through an optical device. In some implementations, the system further includes an illuminator configured to provide light to the optical device, the illuminator disposed in front of the reflective diffractive structure of the optical device.

In some implementations, each of the one or more reflective diffractive structures is configured to diffract a respective one of a plurality of different colors.

In some implementations, the optical device further includes one or more transmissive diffractive structures, each of the one or more transmissive diffractive structures and the one or more reflective diffractive structures displaying a respective color of a plurality of different colors. It is configured to cause diffraction.

Another aspect of the disclosure features an optical device that includes a plurality of optical diffractive components including at least one transmissive diffractive structure and at least one reflective diffractive structure, the optical device comprising When doing so, the optical device is configured to separate the individual colors of light of the different colors while suppressing crosstalk between the different colors.

In some implementations, each of the transmissive and reflective diffractive structures is configured to diffract a respective color of light of a different color.

In some implementations, the optical device further includes at least one reflective layer configured for total internal reflection of at least one of the different colors of light.

In some implementations, the optical device is configured such that light of a particular one of the different colors is incident on a respective one of the optical diffractive components in a first polarization state; of at least one of the different colors such that the light of at least one of the different colors is incident on a respective one of the optical diffractive components in a second polarization state different from the first polarization state. Further including at least one color selective polarizer configured to rotate the polarization state of the light.

Another aspect of the disclosure features a system that includes a display and an optical device according to any one of the optical devices described herein, the optical device diffracting a plurality of different colors of light onto the display. It is configured to allow

Another aspect of the disclosure features a system that includes an illuminator configured to provide a plurality of different colors of light, and an optical device according to any one of the optical devices described herein, the optical The device is configured to diffract light of a plurality of different colors from the illuminator.

In this disclosure herein, the term "primitive" refers to a basic indivisible element for input or output within a computing system. Elements can be geometric or graphical elements. The term "hologram" refers to a pattern displayed by (or uploaded to) a display that includes amplitude or phase information, or some combination thereof, about an object. The term "holographic reconstruction" refers to a volumetric light field (eg, a holographic light field) from a display when illuminated.

The details of one or more implementations of the subject matter herein are set forth in the accompanying drawings and the related description. Other features, aspects, and advantages of the subject matter will be apparent from the specification, drawings, and claims.

It should be understood that various aspects of the implementations can be combined in different ways. As one example, features from a particular method, device, or system may be combined with features from other methods, devices, or systems.

1 illustrates a schematic diagram of an example system including a holographic display. 1 illustrates a schematic diagram of an example holographic display. 1 illustrates an example system for 3D display. 1 illustrates an example configuration for electromagnetic (EM) propagation calculations. 2 illustrates an example EM propagation of point primitives to elements of a display. 2 illustrates an example EM propagation of line primitives to elements of a display. 2 illustrates an example EM propagation of a triangle primitive to an element of a display. 1 illustrates an example implementation of Maxwellian holographic occlusion for point primitives with line primitives as occluders. 2 illustrates an example implementation of Maxwellian holographic occlusion for a line primitive with another line primitive as an occluder. 2 illustrates an example implementation of Maxwellian holographic occlusion for triangle primitives with line primitives as occluders. 2 illustrates an example implementation of Maxwell holographic stitching. 1 is a flowchart of an example process for displaying objects in 3D. 1 illustrates an example system for a 3D display including a reflective display with front illumination. 1 illustrates another example system for a 3D display that includes a reflective display with full-surface illumination. 1 illustrates another example system for a 3D display including a transmissive display with back illumination. 1 illustrates another example system for 3D displays including a transmissive display with waveguide illumination. 1 illustrates another example system for 3D displays including a transmissive display with waveguide illumination. 1 illustrates another example system for a 3D display including a reflective display with waveguide illumination. 1 illustrates another example system for a 3D display including a reflective display with waveguide illumination. 1 illustrates another example system for a 3D display, including a reflective display with optical diffractive illumination using a transmission field grating-based structure. 1 illustrates another example system for 3D displays, including a reflective display with optical diffractive illumination using a reflective field grating-based structure. 1 illustrates another example system for 3D displays, including a transmissive display with optically diffractive illumination using a reflective field grating-based structure. 1 illustrates another example system for 3D displays, including a transmissive display with optical diffraction illumination using a transmission field grating-based structure. 1 illustrates an example display with display elements having non-uniform shapes. 1 illustrates an example display with display elements having different sizes. An example of recording a grid on a recording medium will be illustrated. An example of diffracting a reproduction reference beam by the grating of FIG. 7A is illustrated. An example of recording different colored gratings on a recording medium using different colored lights will be illustrated. An example of recording gratings of different colors on a recording medium using light of the same color will be illustrated. An example is illustrated in which different colored reproduction reference beams are diffracted by different colored gratings. An example of crosstalk between diffracted beams of different colors is illustrated.

An example of recording a diffraction grating having a large reference angle on a recording medium will be illustrated. 1 illustrates an example optical device that includes a two-color diffraction grating and a corresponding color-selective polarizer for individually diffracting two colors of light. 9A illustrates an example of diffracting two colors of light by the optical device of FIG. 9A. 1 illustrates an exemplary optical device that includes a three-color diffraction grating and a corresponding color-selective polarizer for individually diffracting three colors of light. An example of diffracting three colors of light by the optical device of FIG. 10A is illustrated. 1 illustrates an exemplary optical device that includes a two-color diffraction grating and a corresponding reflective layer for individually diffracting two colors of light. 1 illustrates an exemplary optical device that includes a three-color diffraction grating and a corresponding reflective layer for individually diffracting three colors of light. 1 illustrates another exemplary optical device that includes a three-color diffraction grating and a corresponding reflective layer with a wedge-shaped substrate. 2 illustrates a further exemplary optical device including a three-color diffraction grating and a corresponding reflective layer having a wedge-shaped input surface. The relationship between diffracted beam power and reflected beam power with different incident angles for blue light (FIG. 13A), green light (FIG. 13B), and red light (FIG. 13C) is illustrated. The relationship between diffracted beam power and reflected beam power with different incident angles for blue light (FIG. 13A), green light (FIG. 13B), and red light (FIG. 13C) is illustrated. The relationship between diffracted beam power and reflected beam power with different incident angles for blue light (FIG. 13A), green light (FIG. 13B), and red light (FIG. 13C) is illustrated. 1 is a flowchart of an exemplary process for manufacturing an optical device that includes a holographic grating and a corresponding color-selective polarizer. 1 is a flowchart of an exemplary process for manufacturing an optical device that includes a holographic grating and a corresponding reflective layer. 1 illustrates an exemplary optical device that includes a combination of a transmission grating and a reflection grating. 1 illustrates an example of incident light being diffracted by display elements of a display and reflected at gaps between display elements on the display. An example of displaying zero-order light in a holographic scene displayed on a projection screen is illustrated. Figure 2 illustrates an example of displaying zero order light in a holographic scene as displayed to a viewer's eye. An example of suppressing display zero-order light in a holographic scene displayed on a projection screen by diverging display zero-order light is illustrated. Figure 2 illustrates an example of display zero order light in a holographic scene when the display is illuminated with light at normal incidence. An example of suppressing display zero-order light in a holographic scene displayed on a projection screen by directing the display zero-order light away from the holographic scene when the display is illuminated by light at a certain angle of incidence. Illustrate. An example of suppressing display zero-order light in a holographic scene displayed to the viewer's eyes by directing the display zero-order light away from the holographic scene when the display is illuminated with light at a certain angle of incidence. Illustrate. 1 illustrates an example of a construction cone and a reconstruction cone corresponding to a holographic scene for a display in a 3D coordinate system. 20A illustrates an example of adjusting the configuration cone of FIG. 20A to configure a hologram that corresponds to a holographic scene in a 3D coordinate system. An example of coupling light through a coupling prism to an optical diffraction device to illuminate a display at an angle of incidence to suppress display zero-order light in a holographic scene is illustrated. An example of coupling light through a wedge-shaped substrate to an optical diffraction device to illuminate a display at an angle of incidence to suppress display zero-order light in a holographic scene is illustrated. An example of suppressing display zero-order light in a holographic scene displayed on a projection screen by absorbing the display zero-order light reflected from the display with a metamaterial layer is illustrated. One example of suppressing display zero-order light in a holographic scene displayed to a viewer's eye by blocking (or absorbing) the display zero-order light reflected from the display with a metamaterial layer is illustrated. A system for suppressing display zero-order light in a holographic scene by redirecting the display zero-order light away from the holographic scene via an optical redirection structure is illustrated. Figure 2 illustrates an example of redirecting display zero order light to different directions in space via an optical redirection structure. Figure 2 illustrates an example of redirecting display zero order light to different directions in space via an optical redirection structure. Figure 2 illustrates an example of redirecting display zero order light to different directions in space via an optical redirection structure. Figure 2 illustrates an example of redirecting display zero-order light when the light is input at different angles of incidence and in different directions in space through an optical redirection structure. Figure 2 illustrates an example of redirecting display zero-order light when the light is input at different angles of incidence and in different directions in space through an optical redirection structure. Figure 2 illustrates an example of redirecting display zero-order light when the light is input at different angles of incidence and in different directions in space through an optical redirection structure. Figure 2 illustrates an example of redirecting display zero-order light when the light is input at different angles of incidence and in different directions in space through an optical redirection structure. Figure 2 illustrates an example of redirecting display zero-order light when the light is input at different angles of incidence and in different directions in space through an optical redirection structure. An example of redirecting display zero-order light with p-polarization to be transmitted at Brewster's angle is illustrated. We illustrate an example of using an optical retarder to redirect display zero-order light with s-polarization for transmission at the Brewster angle. We illustrate an example of using an optical retarder to redirect display zero-order light with s-polarization for transmission at the Brewster angle. An example of redirecting display zero order light to an anisotropic transmitter to absorb display zero order light is illustrated. An example of redirecting display zero order light to fully reflect the display zero order light is illustrated. We illustrate an example of redirecting two different colors of display zero order light in different directions away from the holographic scene. We illustrate an example of redirecting two different colors of display zero order light in different directions away from the holographic scene. We illustrate an example of redirecting three different colors of display zero order light in different directions away from the holographic scene in the same plane. We illustrate an example of redirecting three different colors of display zero order light in different directions away from the holographic scene in the same plane. We illustrate an example of redirecting three different colors of display zero order light in space to different directions away from the holographic scene. We illustrate an example of redirecting display zero order light of three different colors in different directions away from a holographic scene using a switchable grating for one of the colors. 2 is a flowchart of an example process for suppressing display zero-order light in a holographic scene. 1 illustrates an example system for displaying reconstructed 3D objects. 1 illustrates an example system for displaying reconstructed 3D objects. 1 illustrates an example system for displaying reconstructed 3D objects. 36A-36C illustrate the same views of the system of FIGS. 35A-35C, respectively, with three colors of light propagating within the system. 36A-36C illustrate the same views of the system of FIGS. 35A-35C, respectively, with three colors of light propagating within the system. 36A-36C illustrate the same views of the system of FIGS. 35A-35C, respectively, with three colors of light propagating within the system.

Like reference numbers and designations in the various drawings illustrate like elements.

Implementations of the present disclosure feature techniques for enabling 3D display of complex computer-generated scenes as real holograms. The technique provides a novel and deterministic solution to real-time dynamically computed holography based on Maxwell's equations of electromagnetic fields, which can be expressed as Maxwell holography. A calculation (or calculation) in Maxwell holography can be expressed as a Maxwell holographic calculation (or Maxwell holographic calculation). In embodiments, the present disclosure utilizes tools including field theory, topology, analytic connections, and/or symmetry groups to approach holograms as a Dirichlet or Cauchy boundary condition problem for general electric fields, and this allows solving for holograms in real time without the limitations of traditional holographic systems. In embodiments, this technique can be used to create phase-only, amplitude-only, or phase and amplitude holograms utilizing a spatial light modulator (SLM) or any other holographic device.

Implementations of the present disclosure provide 1) a mechanism for approximating holograms as electromagnetic boundary conditions using field theory and contact geometry instead of classical optics, and 2) a computational approach to electromagnetic boundary conditions to computational holography. 3) derivation and implementation into code and application programming interfaces (APIs), i.e. implementation of hologram calculations as 2D analytical functions on the plane of the hologram and subsequent discretization into parallel algorithms; and/or 3) standard existing An implementation of a complete 3D holographic version of standard computer graphics primitives (e.g., points, lines, triangles, and textured triangles) that can enable full compatibility with other computer graphics tools and techniques. can be provided. These technologies allow devices to display common existing content that has not been created specifically for holography, and at the same time existing content creators do not need to learn special techniques or Allows to create holographic works without the need to use tools.

In particular, the techniques disclosed herein use electromagnetic (EM) instead of the mathematical formulation of classical optics commonly used in computational holography, e.g., the Gerchberg-Saxton (GS) algorithm. ) may involve the use of a mathematical formulation (or representation) of light as a phenomenon. The mathematical formulation disclosed herein is derived from Maxwell's equations. In embodiments, the techniques disclosed herein include treating the displayed image as an electromagnetic field and treating the hologram as a boundary value condition (e.g., a Dirichlet problem) that generates the electromagnetic field. In addition, the desired image can be constructed using primitive paradigms ubiquitous in computer graphics, e.g., any 3D image, rather than as a projected image on a 2D screen, as a holographic reconstruction, e.g. , enabling the technology used to display as a holographic light field. Compared to depth point cloud techniques that suffer from bandwidth limitations, the technique avoids these limitations and uses any suitable type of primitive, e.g. point primitives, line primitives, or polygon primitives such as triangle primitives. can do. Additionally, primitives can be rendered with color, texture, and/or shading information. This can help achieve recording and compression schemes for CG holographic content, including holographic videos.

In embodiments, the techniques disclosed herein calculate the generated hologram as a boundary condition problem to model the electromagnetic field using Maxwell's equations, which is a fast Fourier transform (FFT) and its inherent limitations, removes dependence on collimated light sources such as lasers or light emitting diodes (LEDs), and/or removes limitations of previous approaches to computed holography and non-deterministic solutions. can do.

In embodiments, the techniques disclosed herein employ a mathematical optimization process that constrains independent input to the surface of the hologram depending on the parameters of computer-generated (CG) primitives needed to construct the scene. can be optimized for simplicity and speed of calculation. This allows work to be performed in a highly parallel and highly optimal manner in computing architectures, such as application specific integrated circuits (ASICs) and multi-core architectures. The process of computing a hologram can be thought of as a single instruction executed on input data in the form of a computer-generated imagery (CGI) scene, and theoretically can be performed in a single clock cycle for each CGI primitive. can be completed.

In embodiments, the techniques disclosed herein are functionally compatible with standard primitives of conventional 3D graphics used, for example, in video games, movies, television, computer displays, or any other display technology. We treat a holographic scene as an assembly of fully 3D holographic primitive apertures with a unique nature. These techniques can enable efficient implementation of these aperture primitives in hardware and software without the limitations inherent in standard implementations of computational holography. Primitive amplitudes and colors can be automatically calculated. The computational complexity can increase linearly with the number of phase elements n, compared to n^2 or n*log(n) for standard computational holography. The image created is fully 3D, not a collection of flat images, and the technique does not require iterative amplitude correction with an unknown number of steps. Furthermore, the holograms produced do not have "conjugated" images occupying space on the holographic device.

Because holographic primitives are part of a special collection of mathematical objects, they can be relatively simple and relatively fast to compute, making them uniquely suited to parallel and distributed computing approaches. . The computational possibilities and parallelism of large holograms make it possible to design large-area holographic devices of theoretically unlimited size that can function as holographic computer displays, phone displays, home theaters, and even holographic rooms. Interactive calculations can be made possible. Additionally, holograms can fill large areas with light, e.g. large shaded areas in 3D, without the limitations associated with traditional holographic calculation methods where elements can appear in outline instead of solid. render. Moreover, the relatively simple and relatively fast computation allows display of real-time holograms at interactive speeds unconstrained by n^2 computation burden and iterative amplitude correction.

In embodiments, the technology can realize natural computational possibilities on modern ASIC and multi-core architectures, modern graphics hardware, modern graphics software, and/or modern graphics tools and tool chains. Full compatibility can be achieved with For example, these technologies implement a clear and easy holographic API, through which traditional 3D content creation tools such as 3ds Max®, SOLIDWORKS®, Maya® , or can enable high-performance rendering of arbitrary CG models using Unity. The API may allow a developer or user to interact with a holographic device, such as a light modulator or holographic system. The holographic API allows computer graphics primitives to be created as separate holographic scene primitives, enabling rich holographic content generation utilizing general purpose and specially designed holographic computation hardware. The creation of mathematical and computational architectures can enable holograms to be rendered using tools and techniques used to create traditional 3D content and software applications. Optimization of the mathematical and computational architectures can enable high-performance embodiments of traditional graphics and rendering to be displayed as holographic reconstructions.

The algorithms in the techniques disclosed herein are relatively easy to implement in hardware. This not only allows the computation speed required for the high-quality rendering that users expect, but also allows the algorithm to be implemented in relatively simple circuitry, e.g., an ASIC gate structure, as part of a holographic device. It also becomes possible. Therefore, the bandwidth issues that can plague high-density displays do not have to be computed remotely and then written to each display element (or display pixel) of the display for each frame of content, and the scene computations , can be spread across the computing architecture embedded in the display device (e.g., embedded computation) and can become irrelevant. It also means that the number of display elements, and therefore the size of the holographic display, can be relatively unconstrained by constraints that severely limit other technologies.

The technology disclosed herein supports multiple interactive technologies that use structured light, such as solid-state light detection and ranging (LIDAR) devices, 3D printing and machining, smart illuminators, smart microdisplays, It can be relatively simple and relatively inexpensive to implement in different applications, including optical switching, optical tweezers, or any other application requiring structured light. The techniques disclosed herein can also be used in optical simulations, such as lattice simulations.

FIG. 1A illustrates a schematic diagram of an example system 100 for 3D display. System 100 includes a computing device 102 and a holographic display device (or Maxwell holographic display device) 110. Computing device 102 prepares data for a list of primitives corresponding to an object, e.g., a 3D object, and sends the data to the hologram via a wired or wireless connection, e.g., a USB-C connection or any other high-speed serial connection. The graphics display device 110 is configured to transmit data to the graphics display device 110. The holographic display device 110 calculates electromagnetic (EM) field contributions from a list of primitives to display elements of a display (e.g., a modulator) within the holographic display device 110 and the calculated field contributions on the display. modulating the display element with a pattern, e.g. a hologram, based on the EM field contribution; and displaying a light field, e.g. a holographic reconstruction, corresponding to the object in 3D upon illumination. It is configured. As used herein, hologram refers to a pattern displayed on a display that includes amplitude or phase information, or some combination thereof, about an object. Holographic reconstruction refers to a volumetric light field (eg, a holographic light field) from a display when illuminated.

Computing device 102 may be any suitable type of device, such as a desktop computer, personal computer, notebook, tablet computing device, personal digital assistant (PDA), network appliance, smart cell phone, smart watch, high speed general purpose packet wireless service (EGPRS) mobile phone, media player, navigation device, email device, game console, or any suitable combination of any two or more of these or other computing devices .

Computing device 102 includes an operating system (OS) 104 that may include a number of applications 106 as a graphics engine. Application 106 creates a scene, e.g., any arbitrary CG model, using standard 3D content creation tools, e.g., 3ds Max®, SOLIDWORKS®, Maya®, or Unity. , processed or rendered. A scene may correspond to one or more real or imagined 3D objects, or representations of objects. Applications 106 may operate in parallel to render a scene and obtain an OS graphics abstraction 101 that may be provided to a graphics processing unit (GPU) 108 for further processing. . In some implementations, OS graphics abstraction 101 is provided to holographic display device 110 for further processing.

GPU 108 may include specialized electronic circuitry designed for rapid operation of computer graphics and image processing. The GPU 108 may process the graphics abstraction 101 of the scene to obtain processed scene data 103, which can be used, for example, to obtain a list 105 of indexed primitives in a particular order. be able to. The primitives may include at least one of point primitives, line primitives, or polygon primitives. In some implementations, GPU 108 includes a video driver configured to generate processed scene data 103 and list of primitives 105.

In some implementations, GPU 108 includes a conventional renderer 120 such that list of primitives 105 is rendered onto a conventional monitor 124, e.g., a 2D display screen, by conventional rendering techniques, e.g., culling and clipping. Can be rendered into a list of items to draw. The list of items can be sent to a conventional monitor 124 via a screen buffer 122 .

In some implementations, GPU 108 includes a holographic renderer 130 for rendering list of primitives 105 into graphics data displayed by holographic display device 110. The graphics data may include a list of primitives and corresponding primitive data. For example, the graphics data may include a hexadecimal code for each primitive.

In some implementations, GPU 108 includes both a conventional renderer 120 and a holographic renderer 130. In some implementations, GPU 108 includes a conventional renderer 120 and holographic display device 110 includes a holographic renderer 130.

Corresponding primitive data for a primitive may also include color information (eg, texture color, gradient color, or both), texture information, and/or shading information. Shading information may be obtained by any conventional CGI surface shading method, including modulating the color or brightness of the surface of the primitive.

The primitive data of the primitive can include coordinate information of the primitive in a 3D coordinate system, such as a Cartesian coordinate system XYZ, a polar coordinate system, a cylindrical coordinate system, and a spherical coordinate system. As discussed in more detail below, display elements within holographic display device 110 may also have corresponding coordinate information in a 3D coordinate system. A coordinate location primitive may represent a 3D object adjacent to a display element, eg, in front of a display element, behind a display element, or spanning a display element.

As an example, a primitive is a shaded line, such as a straight line that changes smoothly from one color to another over its span. The primitive requires four elements of data to be rendered: two endpoints and color information (eg, RGB color values) at each endpoint. The hex code of the line is a0, and the line moves from the first end point (0.1, 0.1, 0.1) to the second end point (0.2, 0.2, 0.2) in the 3D coordinate system. ), the color is 1/2 blue, at the first endpoint, RGB=(0,0,128), the color is full red, at the second endpoint, RGB=(255,0 ,0). The holographic renderer determines the amount and type of data expected for each primitive. For lines, the shaded line primitive data in the primitive stream can be a set of instructions such as:
0xa0 //Hex code of shaded line 0x3dccccd //1st vertex (0.1, 0.1, 0.1) float (single)
0x3dccccccd
0x3dccccccd
0x000080 //First vertex color is (0,0,128) 0x3e4ccccd //Second vertex (0.2,0.2,0.2) float (single)
0x3e4ccccd
0x3e4ccccd
0xff0000 //The color of the second vertex is (255,0,0)

There are a total of 31 hexadecimal words in the primitive data for the shaded line primitive.
It can be a very efficient way to transmit complex scenes, and primitive data can be further compressed. No terminator is needed because each primitive is a deterministic Turing step. Unlike traditional models where this line primitive is simply drawn on a 2D display screen, the line primitive data can be used to calculate a hologram and display the corresponding holographic reconstruction presenting the line floating in space. holographic display device 110.

In some implementations, computing device 102 transmits non-primitive-based data, eg, recorded light field video, to holographic display device 110. Holographic display device 110 can compute a sequence of holograms to display the video as a sequence of holographic reconstructions in space. In some implementations, computing device 102 transmits CG holographic content to holographic display device 110 simultaneously with live holographic content. Holographic display device 110 can also compute corresponding holograms and display content as corresponding holographic reconstructions.

As illustrated in FIG. 1A, holographic display device 110 includes a controller 112 and a display 114. Controller 112 may include a number of computing or processing units. In some implementations, controller 112 includes an ASIC, a field programmable gate array (FPGA), or a GPU unit, or any combination thereof. In some implementations, controller 112 includes a holographic renderer 130 for rendering list of primitives 105 into graphics data that is computed by a computing unit. In some implementations, controller 112 receives OS graphics abstraction 101 from computing device 102 for further processing. Display 114 may include a number of display elements. In some implementations, display 114 includes a spatial light modulator (SLM). The SLM may be a phase SLM, an amplitude SLM, or a phase and amplitude SLM. In some examples, display 114 is a digital micromirror device (DMD) or a liquid crystal on silicon (LCOS) device. In some implementations, holographic display device 110 includes an illuminator 116 adjacent to display 114 and configured to emit light toward display 114. The illuminator 116 may include one or more coherent light sources, such as a laser, one or more semi-coherent light sources, such as an LED (light emitting diode) or a superluminescent diode (SLED), one or more non-coherent light sources, or the like. can include a combination of light sources.

Unlike traditional 3D graphics systems that take a 3D scene and render it to a 2D display device, the holographic display device 110 uses a 3D image such as a holographic reconstruction 117 in the form of a light field, e.g. a 3D volume of light. Configured to produce output. In a hologram, each display element can contribute to any part of the holographic reconstruction of the scene. Thus, for holographic display device 110, each display element can potentially be modulated for every part of the scene, e.g., for each primitive in the list of primitives generated by GPU 108, for a complete holographic reproduction of the scene. It is necessary to In some implementations, modulation of certain elements may be omitted or simplified, for example, based on an acceptable level of accuracy within the reproduced scene or within some regions of the scene.

In some implementations, the controller 112 calculates the EM field contribution from each primitive to each display element, e.g., phase, amplitude, or both, and for each display element, calculates the EM field contribution from the list of primitives to the display element. The system is configured to generate a sum of EM field contributions. This can be done by running all primitives and increasing their contribution to a given display element, or by running each display element for each primitive, or by a hybrid blend of these two techniques. I can do it.

Controller 112 may calculate the EM field contribution from each primitive to each display element based on a predetermined formula for the primitive. Different primitives can have corresponding expressions. In some cases, the predetermined equation is an analytic equation, as discussed in more detail below in connection with FIGS. 3A-3C. In some cases, the predetermined equations are determined by solving Maxwell's equations using the boundary conditions defined in display 114. The boundary conditions can include Dirichlet boundary conditions or Cauchy boundary conditions. The display element can then be modulated based on the sum of the EM field contributions, for example, by modulating at least one of the refractive index, amplitude index, birefringence, or retardation of the display element.

If the EM field at each point on the surface bounding the field, e.g. the value of the solution to Maxwell's equations, is known, then determining the exact and unique configuration of the EM field within the volume bounded by the bounding surface I can do it. The list of primitives (or the holographic reconstruction of the corresponding hologram) and the display 114 define a 3D space, and the surface of the display 114 forms part of the boundary of the 3D space. Determining boundary conditions of the EM field by setting an EM field state (e.g., a phase state or an amplitude state or a phase and amplitude state) on the surface of the display 114, e.g., by shining light onto the display surface. I can do it. Due to the time symmetry of Maxwell's equations, the display element is modulated based on the EM field contribution from the primitive corresponding to the hologram, so that a volumetric light field corresponding to the hologram can be obtained as a hologram reconstruction.

For example, a line primitive of illumination in a particular color can be set in front of the display 114. As discussed in more detail below with respect to FIG. 3B, the analytical expression for a linear aperture can be written as a function in space. The EM field contribution from line primitives on the interface containing display 114 can then be determined. When the EM field value corresponding to the calculated EM field contribution is set on the display 114, due to the time symmetry of Maxwell's equations, the same linear aperture used in the calculation will be used at the corresponding location, e.g. It can appear at the coordinate position of a linear primitive in the system and in a particular color.

In some examples, assume that there is a line of light between two points A and B in 3D space, as discussed in more detail below with respect to FIG. 3B. The light is evenly illuminated and has an intensity I per linear distance l. For every infinitesimal dl along the line from A to B, an amount of light proportional to I*dl is emitted. The infinitesimal dl acts as a delta (point) source and the EM field contribution from the infinitesimal dl to any point on the boundary surface around the scene corresponding to the list of primitives can be determined. Thus, for any display element of display 114, an analytical expression representing the EM field contribution at the display element from an infinitesimal segment of a line can be determined. A special addition/integration that progresses along the line and increases the EM field contribution of the entire line to the EM field at the display element of the display can be determined as a formula. A value corresponding to the expression can be set at the display element, for example by modulating the display element and illuminating the display element. Time reversal and correction constants can then create a line at the same location defined by point A and point B in 3D space.

In some implementations, controller 112 is coupled to display 114 through a memory buffer. The controller can generate respective control signals based on the sum of the EM field contributions to each of the display elements. The control signal is for modulating the display element based on the sum of the EM field contributions. Each control signal is transmitted to a corresponding display element via a memory buffer.

In some implementations, controller 112 is integrated with and locally coupled to display 114. As discussed in further detail in connection with FIG. 1B, controller 112 may include a number of computing units, each coupled to one or more respective display elements, and The display element is configured to transmit a respective control signal to each of the one or more respective display elements. Each computing unit may be configured to perform computations on one or more primitives of the list of primitives. Computing units can operate in parallel.

In some implementations, illuminator 116 is coupled to controller 112 and configured to turn on and off based on control signals from controller 112. For example, controller 112 may activate illuminator 116 to turn on in response to controller 112 completing a calculation, e.g., obtaining a total of all EM field contributions for a display element. can. As mentioned above, when the illuminator 116 emits light onto the display 114, the modulated elements of the display propagate the light in different directions to create a volumetric light field corresponding to the list of primitives corresponding to the 3D object. form. The resulting volumetric light field corresponds to a solution of Maxwell's equations with boundary conditions defined by the modulated elements of display 114.

In some implementations, controller 112 is coupled to illuminator 116 through a memory buffer. The memory buffer may be configured to control the amplitude or brightness of the light emitting elements within the illuminator. The memory buffer for illuminator 116 may have a smaller size than the memory buffer for display 114. Some of the light emitting elements in illuminator 116 may be smaller than some display elements of display 114 so long as light from the light emitting elements can illuminate substantially the entire surface of display 114. For example, an illuminator with 64x64 OLEDs (organic light emitting diodes) can be used for a display with 1024x1024 elements. Controller 112 may be configured to operate several illumination elements of illuminator 116 simultaneously.

In some implementations, illuminator 116 is a monochromatic light source configured to emit substantially monochromatic light, eg, red light, green light, yellow light, or blue light. In some implementations, illuminator 116 includes two or more light emitting elements, such as lasers or light emitting diodes (LEDs), each configured to emit light having a different color. For example, illuminator 116 can include red, green, and blue illumination elements. To display a full-color 3D object, three or more separate holograms for colors including at least red, green, and blue can be calculated. That is, at least three EM field contributions from the corresponding primitives to the display element can be obtained. The display elements can be modulated sequentially based on at least three EM field contributions, and the illuminator 116 can be controlled to turn on at least the red, green, and blue illumination elements sequentially. For example, controller 112 may transmit a first timing signal to turn on a blue illumination element and transmit a first control signal corresponding to a blue hologram to display elements of display 114. After the blue hologram on the display 114 is illuminated with blue light for a first time period, the controller 112 transmits a second timing signal to turn on the green illumination element and turn on a second timing signal corresponding to the green hologram. Control signals may be transmitted to display elements of display 114. After the green hologram on the display 114 is illuminated with green light for a second period, the controller 112 transmits a third timing signal to turn on the red illumination element and turn on the third timing signal corresponding to the red hologram. Control signals may be transmitted to display elements of display 114. After the red hologram on display 114 is illuminated with red light for a third period, controller 112 may repeat the above steps. Depending on the temporal coherence of the visual effects in the viewer's eyes, the three colors can be combined in the eye to give a full color appearance. In some cases, the illuminator 116 is turned off during a state change of the display image (or holographic reconstruction) and turned on when a valid image (or holographic reconstruction) is presented for a period of time. Ru. This can also rely on the temporal coherence of vision to make the image (or holographic reconstruction) appear stable.

In some implementations, display 114 has a resolution small enough to diffract visible light at orders of 0.5 μm or less, for example. Illuminator 116 can include a single white light source, and the emitted white light can be diffracted into different colors by display 114 for holographic reconstruction.

Different configurations for system 100 may exist, as discussed in more detail below with respect to FIGS. 5A-5K. Display 114 may be reflective or transmissive. Display 114 can have a variety of sizes ranging from small (eg, 1-10 cm on a side) to large (eg, 100-1000 cm on a side). Illumination from illuminator 116 may be from in front of display 114 (eg, in the case of a reflective or transflective display) or from behind the display 114 (eg, in the case of a transmissive display). Holographic display device 110 can provide uniform illumination across display 114. In some implementations, optical waveguides can be used to uniformly illuminate the surface of display 114, as illustrated in FIGS. 5D-5G. In some examples, controller 112, illuminator 116, and display 114 may be integrated together as a single unit. An integrated single unit may include, for example, a holographic renderer 130 within the controller 112.

In some implementations, an optical diffraction device, e.g., a field grating device or light guide device as illustrated in FIGS. 5H-5K, is configured to diffract light from the illuminator 116 to the display 114. The display 114 can then diffract the light to the viewer's eyes. In some examples, light from the illuminator 116 can enter the optical diffractive device from the side at a large angle of incidence so that the illuminator 116 does not block the viewer's view of the display 114. In some examples, the diffracted light from the optical diffraction device is such that the light can illuminate the display relatively uniformly and be diffracted to the viewer's eye with reduced (e.g., minimal) loss. can be diffracted at nearly normal incidence to the display.

FIG. 1B illustrates a schematic diagram of an example holographic display device 150. Holographic display device 150 may be similar to holographic display device 110 of FIG. 1A. Holographic display device 150 includes a computing architecture 152 and a display 156. Computing architecture 152 may be similar to controller 112 of FIG. 1A. Computing architecture 152 may include an array of parallel computing cores 154. A computing core may be connected to an adjacent computing core via a communication connection 159, such as a USB-C connection or any other high speed serial (or parallel) connection. Connections 159 can be included in a data distribution network in which scene data 151 (eg, scene primitives) can be distributed among computing cores 154.

Display 156 may be similar to display 114 of FIG. 1A and may include an array of display elements 160 positioned on backplane 158. Display element 160 may be located on the front side of backplane 158 and computing core 154 may be located on the back side of backplane 158. Backplane 158 may be a substrate, such as a wafer. Computing core 154 may be either on the same substrate as display 156 or bonded to the back side of display 156.

Each computing core 154 may be connected to a respective tile (or array) of display elements 160. Each computing core 154 may be configured to perform computations on each of a number of primitives in scene data 151 in parallel with one or more other computing cores. In some examples, the computing core 154 calculates the EM field contribution from each of the respective primitives to each of the display elements 160 and the EM field contribution from the number of primitives to each of the respective tiles of the display elements 160. configured to generate a sum of field contributions. Computing core 154 receives the calculated EM field contribution from other of the number of primitives to each tile of display element 160 from other computing cores of array of computing cores 154; and a total EM field contribution can be generated based on the received calculated EM field contribution. Computing core 154 generates control signals for each of the respective tiles of display element to determine at least one characteristic of each of the respective tiles of display element 160 based on the sum of the EM field contributions to the display element. Can be modulated.

As discussed above, computing architecture 152 also provides control to illuminator 162, e.g., in response to determining that the calculation of the total EM field contribution from a number of primitives to each of the display elements is complete. A signal can be generated. The illuminator 162 emits input light 153 to illuminate the modulated display element 160, and the input light 153 is diffracted by the modulated display element 160 to form a volumetric light field corresponding to the scene data 151, e.g. , forming a holographic light field 155.

As illustrated in FIG. 1B, tiles of display elements 160 can be interconnected into a larger display. Correspondingly, computing cores 154 may be interconnected for data communication and distribution. Note that the parameter that varies in the holographic calculation between two given display elements is their physical location. Therefore, the task of computing a hologram can be shared equally between corresponding computing cores 154, and the entire display 150 can operate at the same speed as a single tile, regardless of the number of tiles. .

FIG. 1C illustrates an example system 170 for displaying objects in 3D space. System 170 can include a computing device, eg, computing device 102 of FIG. 1A, and a holographic display device 172, eg, holographic display 110 of FIG. 1A or 150 of FIG. 1B. A user may operate system 170 using input devices, such as keyboard 174 and/or mouse 176. For example, a user can create CG models of 2D object 178 and 3D object 180 through a computing device. Computing device or holographic display device 172 includes a holographic renderer, such as holographic renderer 130 of FIG. 1A, for rendering the CG model and generating corresponding graphics data for 2D object 178 and 3D object 180. can include. The graphics data may include primitive data for each of the lists of primitives corresponding to objects 178 and 180.

Holographic display device 172 may include a controller, eg, controller 112 of FIG. 1A or 152 of FIG. 1B, and a display 173, eg, display 114 of FIG. 1A or 156 of FIG. 1B. The controller may calculate respective sums of EM field contributions from the primitives to each display element of display 173 and generate control signals for modulating each display element based on the respective sums of EM field contributions. can. Holographic display device 172 may further include an illuminator, such as illuminator 116 of FIG. 1A or illuminator 162 of FIG. 1B. A controller can generate timing control signals to operate the illuminator. When light from the illuminator illuminates the surface of display 173, the modulated display elements cause the light to propagate in 3D space to produce a holographic reconstruction of the 2D view of object 178 and a holographic reconstruction of the 3D object 180. A volumetric light field corresponding to the graphical reconstruction can be formed. Thus, the 2D view of object 178 and the 3D holographic reconstruction of object 180 are displayed as respective holographic reconstructions floating in 3D space in front of display 173, behind display 173, or across the displays.

In some implementations, the computing device transmits non-primitive-based data, such as recorded light field video, to the holographic display device 172. The holographic display device 172 may calculate and generate corresponding holograms, eg, a series of consecutive holograms, and display them as corresponding holographic reconstructions in 3D space. In some implementations, the computing device transmits the CG holographic content to the holographic display device 172 simultaneously with the live holographic content. Holographic display device 172 may also compute and generate corresponding holograms to display the content as a corresponding holographic reconstruction in 3D space.

FIG. 2 illustrates an example configuration 200 for electromagnetic (EM) field calculations. A display 202, eg, an LCOS device that includes an array of elements 204 and a list of primitives, including point primitives 206, is in 3D space 208. 3D space 208 includes a boundary surface 210. In the 3D coordinate system XYZ, the point primitive 206 has coordinate information (x, y, z). Each display element 204 lies in a flat plane with respect to other display elements 204 and has a 2D position (u,v). Display element 204 also has a location in 3D space. By mathematical point transformation, the 2D position (u,v) can be transferred to six coordinates 250 in the 3D coordinate system. That is, the surface of display 202 forms part of interface 210. Therefore, the EM field contribution from the list of primitives to the display element calculated by defining boundary conditions at the surface of display 202 represents a portion of the total EM field contribution from the primitives to the display element. The sum of the EM field contributions for each of the display elements can be multiplied by a scale factor, e.g., 6, to obtain a scaled sum of the field contributions, and the display elements are It can be modulated based on

Exemplary EM Field Contributions for Primitives Primitives can be used for computer graphics rendering. Each type of primitive in computer graphics, in the formulation of the techniques disclosed herein, corresponds to a discrete mathematical function that defines a single holographic primitive of graphical elements added to the hologram. Each type of primitive can correspond to a formula for calculating the EM field contribution to the display element. Primitives may be point primitives, line primitives, or polygonal (eg, triangle) primitives. As illustrated below, analytical expressions can be derived by calculating the EM field propagation from the corresponding primitives to the display elements of the display.

FIG. 3A illustrates example EM propagation from point primitive 304 to element 302 of display 300. In the 3D coordinate system XYZ, assume that the z-coordinate is 0 across the display 300, meaning that negative z-values are behind the display 300 and positive z-values are in front of the display 300. Point primitive 304 has coordinates (x,y,z) and display element 302 has coordinates (u,v,0). The distance d _uv between point primitive 304 and display element 302 can be determined based on their coordinates.

Point primitive 304 can be thought of as a point charge with a time-varying amplitude. According to electromagnetic theory, the electric field E generated by such a point charge is
It can be expressed as,
In the formula, λ represents the wavelength of the EM wave, and d represents the distance from the point charge.

Therefore, the electric field E _u, v in the display element (u,v) is
It can be expressed as,
where I represents the relative strength of the holographic primitive electric field in the display element contributed from point primitive 304.

As discussed above with respect to FIG. 2, the surface of display 300 forms only a portion of the EM field interface. A scale factor S can be applied to the electric field E _u,v to obtain a scaled electric field E _φ (u,v) in the display element adjusting the sub-boundary as follows.

FIG. 3B illustrates an example of EM propagation from line primitive 306 to display element 302 of display 300 in the 3D coordinate system XYZ. As mentioned above, display element 302 can have coordinates (u,v,0), where z=0. Line primitive 306 has two endpoints P ₀ with coordinates (x ₀ , y ₀ , z ₀ ) and P ₁ with coordinates (x ₁ , y ₁ , z ₁ ). The distance d ₀ between the end point P ₀ and the display element can be determined based on their coordinates. Similarly, the distance d ₁ between the endpoint P ₁ and the display element can be determined based on their coordinates. The distance d ₀₁ between the two end points P ₀ and P ₁ can also be determined, for example d ₀₁ =d ₁ -d ₀ .

As discussed above, a line primitive can be treated as a superposition or a linear deformation, and the corresponding analytical expression of a line primitive as a linear aperture can be obtained as a distributed delta function in space. This analytical formula can be a closed formula for continuous 3D line segments as a hologram.

FIG. 3C illustrates example EM propagation from triangle primitive 308 to display element 302 of display 300 in a 3D coordinate system XYZ. As mentioned above, display element 302 can have coordinates (u,v,0), where z=0. Triangle primitive 308 has three endpoints, P ₀ (x ₀ , y ₀ , z ₀ ), P ₁ (x ₁ ,y ₁ ,z ₁ ), and P ₂ (x ₂ ,y ₂ ,z ₂ ). . The distances d ₀ , d ₁ , and d ₂ between the display element and the endpoints P ₀ , P ₁ , and P ₂ , respectively, can be determined based on their coordinates.

Similar to the line primitive of FIG. 3B, the triangle primitive can be treated as a continuous aperture in space, and an analytical expression for the EM field contribution of the triangle primitive to the display element can be obtained by integration. This can be simplified to obtain a formula for efficient calculation.

Exemplary Calculations for Primitives As discussed above, a controller, e.g., controller 112 of FIG. Contribution can be calculated. As an example, calculate the EM field contribution for a line primitive as follows.

Each display element within the display has a physical location in space, and each display element is located in a flat plane with respect to other display elements. Assuming that the display elements and their controllers are conventionally laid out in the display and memory devices, a simple mathematical point transformation can be used to locate the display elements based on their logical memory addresses within the processor. The logical location of a given display element can be translated into an actual physical location of the display element in space. Thus, when the logical memory address of a display element is looped over within the processor's logical memory space, the corresponding actual physical location in space across the surface of the display can be identified.

As an example, if a display has a 5 μm pitch in both x and y, each logical address increment can move 5 μm in the x direction, and once the x resolution limit of the display is reached, the next increment is Move back to the target location and increment the y-physical location by 5 μm. The third spatial coordinate z can be assumed to be zero across the display surface, meaning that negative z values are behind the display and positive z values are in front of the display.

To begin the line calculation, the types of scaled physical distances between the current display element and each of the two points of the line primitive can be determined to be d ₀ and d ₁ . In fact, d ₀ and d ₁ can be calculated once per primitive, since every subsequent calculation of the distance across the display element is a small perturbation of the initial value. In this way, this calculation is performed in one dimension.

An example computation process for each primitive is the computation code below,
DD=f(d1,d0),
iscale=SS*COLOR*Alpha1,
C1=-2*iscale*sin(DD/2)*sin(Alpha2)*cos(Alpha3),
C2=-2*iscale*sin(DD/2)*sin(Alpha2)*sin(Alpha4),
where SS, Alpha1, Alpha2, Alpha3, and Alpha4 are precomputed constants, COLOR is an RGB color value passed in a primitive, and all values are scalar single-precision floats. Both sine and cosine functions can be looked up in tables stored in the controller to improve calculation efficiency.

The results in C1 and C2 may then be accumulated for each primitive in each display element, for example in an accumulator for the display element, and normalized once at the end of the calculation for the display element. At this point, the controller transmits a first control signal to the display element to modulate the display element based on the calculated result, and a second control signal to the illuminator, as described above. can be turned on to emit light. Therefore, the holographic reconstruction (or holographic light field) is visible to the viewer. When illuminated, the modulated display element can cause the light to produce sharp, continuous lines of color in three-dimensional space.

In some implementations, the calculation code includes a hexadecimal code to clear the previous accumulation in the accumulator, eg, at the beginning of the code. The calculation code may also include, for example at the end of the code, a hexadecimal code for storing the accumulator result in a respective memory buffer for each display element. In some implementations, a computing device, e.g., computing device 102 of FIG. 2. Transmit the target primitive hex code to the controller. The computing device then sends one or more combinations of hex codes, potentially along with other foreground or dynamic primitives, to a controller that can form corresponding control signals for modulating display elements of the display. , can be transmitted at much higher rates.

The calculation process can be orders of magnitude simpler and faster than most efficient line drawing routines in conventional 2D display technology. Furthermore, this calculation algorithm scales linearly with some display elements. Therefore, scaling the controller's computing unit as a 2D network processing system can keep up with the increasing surface area computing needs of the display.

Exemplary Calculation Implementation The Maxwell holographic controller, e.g., controller 112 of FIG. 1A, calculates the EM field contribution from the primitives to the display element based on analytical expressions that can be determined as shown above. Can be done. The controller may be implemented in, for example, an ASIC, FPGA or GPU, or any combination thereof.

In modern GPU pipelines, the GPU takes a description of a geometric figure and vertex and fragment shader programs and produces color and depth pixel output on one or more output image surfaces (referred to as rendering targets). The process involves an information explosion fanout where the geometry is expanded into shaded fragments, followed by a visibility test to select whether or not work should be done on each of these fragments. be done. A fragment is a record containing all the information involved in shading that sample point, eg, triangle centroid coordinates, interpolated values like color or texture coordinates, surface derivatives, etc. The process of creating these records and then rejecting records that do not contribute to the final image is visibility testing. Fragments that pass visibility tests can be packed into work groups called wavefronts or warps, which are executed in parallel by the shader engine. These are written to memory as pixel values, producing output values ready for display or use as input textures for later rendering passes.

Maxwell holography can greatly simplify the rendering process. In Maxwell's holographic computation, any primitive can contribute to any display element. There is no need to scale the geometry to pixels, and there is no need to apply visibility tests before packing the wavefront. This also eliminates the need for decision-making or communication between Maxwellian holographic pipelines and can allow calculations to be a problem in parallel with several possible solutions, each of which Solutions are tailored for speed, cost, size, or energy optimization. Graphics pipelines are significantly shorter, with fewer intermediate steps, no data copying or movement, and fewer decisions to make for lower latency between starting drawing and having the result ready for display. This can allow Maxwell holographic rendering to create very low delay displays. As discussed below, this means that Maxwellian holographic calculations can increase precision, e.g. by using fixed point in the Maxwellian holographic pipeline, and by optimizing mathematical functions, e.g. It is possible to optimize the calculation speed.

Using Fixed Point When calculating the EM contribution from each primitive at each display element (or "phasel"), intermediate calculations involve generating very large numbers. These large numbers require special handling because you also need to preserve the fractional part during calculations.

Floating point values have the disadvantage of being closest in precision to the origin (zero on the number line) and losing one bit of precision for every power of two away from the origin. For numbers close to the range [-1, 1], the precision of floating-point numbers is exquisite, but when you reach numbers in the tens of millions, for example, single-precision 32-bit IEEE-754 floating-point values have no decimal places left. When a point is reached where no value is reached, the entire mantissa (also known as mantissa) is used to represent the integer part of the value. However, it is the fractional parts of large numbers that Maxwell's holography is particularly interested in preserving.

In some cases, fixed point is used for Maxwellian holographic calculations. A fixed-point representation is a number where the decimal point does not change from case to case. By choosing the correct number of bits in the integer and fractional parts of a number, it is possible to obtain the same number of fractional bits regardless of the size of the number. Fixed-point numbers are represented as integers with an implicit scale factor; for example, 14.375 may be represented as the number 3680 (0000111001100000 binary) in a 16-bit fixed-point value with 8 fractional bits. This can also be expressed as "unsigned 16.8" fixed point, or u16.8 for short. Negative numbers can have one additional sign bit and are stored in a "compliment of two" format. In this way, the accuracy of calculations can be significantly improved.

Optimization to Mathematical Functions As indicated above, Maxwellian holographic computations include the use of transcendental mathematical functions, such as sine, cosine, arc-tangent functions, and the like. On the CPU, these functions are implemented as floating point library functions that can use special CPU instructions, or on the GPU, as floating point units in the GPU. These functions are written to accept arguments as floating point numbers, and the results are returned in the same floating point representation. These functions are exact if the float is exact, round correctly, and handle all edge cases of floating point representation (infinity, NaN, signed zero, and denormalized floats). , is built for common cases.

In Maxwellian holographic computations, floating point representations do not require the use of denormalized floats for gradual underflow, nor do they require handling NaN results from operations such as division by zero to change the floating point rounding mode. There is no need and no need to raise a floating point exception to the operating system. All of these allow, for example, to simplify (and/or optimize) transcendental mathematical functions, as discussed below.

In some cases, optimizations can be made to take arguments in one fixed point format and return values to different precision levels, eg, input s28.12 and output s15.14. This may be particularly desirable when computing the sine of tens of millions of large values, where the input argument can be large, but the output is only the arctangent, which accepts the value range [-1, 1], or any value. , but may return values within the range [-π/2, π/2].

In some cases, depending on the input range involved, the transcendental function can be expressed as a fully enumerated lookup table, as an interpolated table, as a half-table-based polynomial function, or as a half-table-based fully minimal As a polynomial, it can be freely implemented and optimized. It also allows general-purpose GPU pipeline calculations to apply specialized range reduction methods to deal with large inputs that can be skipped for speed.

In some cases, another optimization is to convert trigonometric calculations from the range [-π, π] to signed 2 in the range [-1, 1], which has the advantage of not requiring expensive 2π division operations. can be converted into a complimentary expression.

Exemplary Implementation for Occlusion Occlusion is often considered a difficult and important topic in computer graphics, and even more so in computational holography. This is because, at least in some cases, occlusion problems in projection CGI are static, whereas what is hidden and what is visible in holographic systems depends on the location, orientation, and direction of the viewer. . The wave approach of GS holography, or its derivatives, was developed to address holographic occlusion. However, masking or blocking contributions from parts of the scene that are behind other parts of the scene can be very complex and computationally expensive in GS methodologies.

In Maxwellian holography, the occlusion problem can be handled relatively easily because it is completely deterministic and self-evident which display element (e.g., phasel) corresponds to which primitive. For example, whether a given display element contributes to the reconstruction of a given primitive can be determined when computations for the given primitive are performed. When calculating the sum of EM contributions to one of several display elements after determining that some display elements do not contribute to a given primitive due to occlusion, the EM contribution from a given primitive is omitted from the calculation of the total EM contribution to one of several display elements.

For purposes of illustration only, FIGS. 3D-3F show the determination of display elements that do not contribute to a given primitive (a point in FIG. 3D, a line in FIG. 3E, and a triangle in FIG. 3F) using line primitives as occluders. . A line primitive has a starting point O1 and an ending point O2.

As illustrated in FIG. 3D, point primitive P0 is behind the occluder and close to the display. By extending the line connecting O1-P0 and the line connecting O2-P0, the range of display elements D1-D2 in the display that does not contribute to the reconstruction of point primitive P0 is determined.

In some examples, the O1, O2, and P0 coordinate information stored in the "Z" buffer, computed by a GPU (e.g., GPU 108 in FIG. , is known before being transmitted to the controller 112 of FIG. 1A). For example, in the XZ plane with y=0, the coordinate information can be O1 (Ox1, Oz1), O2 (Ox2, Oz2), and P0 (Px, Pz), with Oz1=Oz2=Oz. Based on the coordinate information, the coordinate information of D1 and D2 is
It can be determined that Dx1=Px+ρ(Px-Ox2), Dx2=Dx1+ρ(Ox2-Ox1) (4),
In the formula, ρ=Pz/(Oz−Pz) and Dz1=Dz2=0.

The information in D1 and D2 can be stored as additional information in the "S" buffer of the Maxwell holographic controller in addition to the information in the Z buffer of point primitive P0. In this way, the additional information can be used to trivially mask the contribution of a particular display element (within the range D1-D2) to a particular primitive P0 in the indexed primitive list.

FIG. 3E illustrates determining how a particular display element contributes to a line primitive that has an occluder in front of (or in front of) the line primitive. By connecting a particular display element D0 to the starting point O ₁ and ending point O ₂ of the occluder, two point primitives P1 and P2 on the line primitive are determined as an intersection point. Therefore, the particular display element D0 does not contribute to the reconstruction of the part of the line primitive from P1 to P2 on the line primitive. Therefore, when calculating the total EM contribution to a particular display element D0, the EM contribution from the portions P1-P2 of the line primitive is not calculated.

This can be implemented in two ways. In the first method, the EM contribution from the portions P0-P1 and P2-Pn to a particular display element D0 is calculated by calculating the EM contribution of a line primitive to a particular display element D0 by considering the occlusion from the occluder. It is totaled as In the second method, the EM contribution from the whole line primitives P0-Pn is calculated together with the EM contribution from the parts P1-P2, and the difference between the two calculated EM contributions is calculated by considering the occlusion from the occluder. It can be considered as the EM contribution of a line primitive to a particular display element D0. The coordinate information of P1 and P2 or portion P1-P2 is stored in the Maxwell holographic controller, along with the occluder information and other information in the GPU's "Z" buffer, as part of the line primitives that do not contribute to a particular display element D0. can be stored in the "S" buffer of

FIG. 3F illustrates determining how a particular display element contributes to a triangle primitive with an occluder in front of the triangle primitive. By connecting a particular display element D0 to the starting point O1 and ending point O2 of the occluder, four point primitives P1, P2, P3, and P4 on the sides of the triangle primitive are determined as intersection points. Therefore, the particular display element D0 does not contribute to the reconstruction of the part of the triangle primitive bounded by the points P1, P2, P3, P4, _PC . Therefore, when computing the sum of the EM contributions to a particular display element D0, the EM contributions from the portions P1-P2-P3-P4- _PC of the triangle primitive are not computed. That is, by considering the occlusion of the occluder, only the EM contribution from the first triangle formed by points P _A , P1, and P2 and the second triangle formed by points P _B , P3, and P4 are summed as the EM contributions of the triangle primitives P _A - P _B - P _C. The coordinate information of P1, P2, P3, and P4 or triangle primitives P _A - P1 - P2 and P _B - P3 - P4, along with occluder information and other information in the GPU's "Z" buffer, is It can be stored in the "S" buffer of the Maxwell holographic controller as part of the triangle primitives P _A - P _B - P _C contributing to element D0.

The implementation of occlusion in Maxwell holography allows converting a "Z" buffer in the GPU to an "S" buffer in the Maxwell holographic controller, allowing you to convert specific primitives (or The contribution of certain parts of primitives to certain display elements can be masked. This not only provides accurate and physically correct occlusion, but also allows calculations to take longer because primitives that do not contribute to a given display element can be ignored and the calculation can be moved to the calculation of the next display element. Save money too. The "S" buffer may contain additional information related to the diffraction efficiency of the display.

The "S" buffer may also include rendering features such as holographic specular highlights where the reflectance of the surface depends on the viewing angle. In traditional CGI, specular highlights depend only on the orientation of the rendered object, but in a Maxwellian holographic context, the direction in which the object is displayed also plays a role. Therefore, geometric specular information can be encoded in the "S" buffer as an additive (specular) rather than a subtractive (occlusion) contribution. In Maxwellian holography, the mathematics of holographic specular highlights can be virtually the same as holographic occlusion.

Exemplary Implementation for Stitching When light illuminates a display that is modulated with EM contributions from a list of primitives of a 3D object, the modulated display propagates the light in different directions to form a volumetric light field corresponding to . The volumetric light field is a Maxwellian holographic reconstruction. Two adjacent primitives in a 3D object, eg, two triangle primitives, have a common side (eg, an edge or surface). During reconstruction, stitching problems may occur, and reconstruction of two adjacent primitives can double the light intensity on a common edge. This can affect the appearance of the reconstructed 3D object.

To address the stitching problem in Maxwellian holography, adjacent primitives are shrunk by a predetermined factor so that gaps can be formed between adjacent primitives, as illustrated in Figure 3G. be able to. In some cases, instead of shrinking two adjacent primitives, only one primitive or a portion of a primitive is reduced. For example, a line of a triangle primitive can be reduced to separate it from another triangle primitive. In some cases, scaling may include scaling different portions of the primitive with different predetermined factors. Scaling is designed so that gaps are large enough to separate adjacent primitives and minimize stitching problems, and small enough so that the reconstructed 3D object appears seamless. be able to. The predetermined coefficients are based on display and viewer information, e.g. the maximum spatial resolution of the holographic light field and, if that part of the primitive appears completely or partially behind the display, the minimum distance from the viewer to that part of the primitive. It can be determined based on distance.

In some cases, the scaling operation can be applied to primitive data of a primitive obtained from a holographic renderer, e.g., holographic renderer 130 of FIG. 1A, and the scaled primitive data of the primitive is A graphics controller, such as controller 112 of FIG. 1A. In some cases, the controller may perform a scaling operation on the primitive data obtained from the holographic renderer before calculating the EM contribution of the primitive to the display element of the display.

Exemplary Implementation for Texture Mapping Texture mapping is a technique developed in computer graphics. The basic idea is to take a source image and apply it as a decal to the surface of a CGI system, allowing details to be rendered into the scene without the need for adding complex geometry. Texture mapping can include techniques for creating realistic illumination and surface effects within CGI systems, and can universally refer to the application of surface data to triangular meshes.

Maxwell holography uses analytical relationships between arbitrary triangles in space and topological diagrams on the holographic device to render flat shaded and also interpolated meshes of triangles in true 3D. can do. However, to be compatible with modern rendering engines, the ability to map information on the surfaces of these triangles is desirable. This can present a practical problem in that the speed of the method is derived from the existence of analytical mappings that do not allow data-driven amplitude changes.

Discrete cosine transform (DCT) is an image compression technique and can be thought of as a real-valued version of FFT (Fast Fourier Transform). DCT relies on an encoding-decoding process that assigns weights to cosine harmonics within a given image. The result of encoding is a set of weights equal to the number of pixels in the original image, and no information is lost when reconstructing the image using any weights. However, for many images, acceptable reconstruction can be done from a small subset of weights, allowing large compression ratios.

The DCT decoding (rendering) process in two dimensions involves a weighted double sum over every DCT weight and every destination pixel. This can be applied to Maxwellian holography for texture mapping. In Maxwellian holography, triangle rendering involves "spiked" double integration in phase space to determine the phase contribution of individual phasers to the triangle in question. The integrals are folded into double sums that mirror those in the DCT reconstruction, and then the analytic triangulation equations can be derived again in terms of the DCT weights. This implementation of DCT techniques in Maxwellian holographic computations draws complete texture mapping triangles, applies image compression to the rendered texture triangle data, and automatically converts texture and image data using DCT, such as JPEG. It allows you to leverage existing toolsets that compress data automatically.

In some implementations, to draw Maxwellian holographic textured triangles, the desired spatial resolution for mapping on a specified surface is first calculated. The texture with resolution is then provided and compressed with angle and origin information to obtain a DCT correctly oriented on the triangle. The list of triangle angles and DCT weights is then included in the indexed primitive list and sent to the Maxwell holographic controller. DCT weights may be included in the triangle primitive's EM contribution to each display element. Textured triangles can be n times slower than flat triangles, where n is the number of (non-zero) DCT weights sent with the primitive. Modern techniques for "fragment shading" can be implemented in Maxwellian holographic systems, where the DCT encoding step replaces the filter step for traditional projection rendering.

As an example, the expression
M and N are the corners of the rectangular image and (p, q) are the DCT terms.

By decoding, the amplitude value A _mn is

When calculating the EM contribution of a textured triangle primitive to a display element (e.g. a phasel), the DCT term with the corresponding DCT weight A* _mn is
can be included in the calculation like,
where X, Y are the corners of the triangle in the coordinate system, T corresponds to the EM contribution of the triangle primitive to the display element, and φ _pq is the partial contribution of the nonzero term B _pq in the DCT . The number of (p,q) DCT terms can be selected by considering both information loss in reconstruction and information compression.

Exemplary Process FIG. 4 is a flowchart of an exemplary process 400 for displaying objects in 3D. Process 400 may be performed by a controller for the display. The controller may be controller 112 of FIG. 1A or 152 of FIG. 1B. The display may be display 114 in FIG. 1A or 156 in FIG. 1B.

Data is obtained including respective primitive data for primitives corresponding to objects in 3D space (402). Data may be obtained from a computing device, such as computing device 102 of FIG. 1A. A computing device can process the scene to generate primitives that correspond to objects. The computing device can include a renderer for generating primitive data for the primitives. In some implementations, the controller generates the data itself, for example, by rendering a scene.

The primitives may include at least one of point primitives, line primitives, or polygon primitives. The list of primitives is, for example, indexed in a particular order that allows objects to be reconstructed. The primitive data may include color information having at least one of a texture color, a gradient color, or a constant color. For example, a line primitive can have at least one of a gradient or texture color, or a constant color. Polygon primitives may also have at least one of a gradient color, a texture color, or a constant color. Primitive data may also include texture information for the primitive and/or shading information on one or more surfaces of the primitive (eg, a triangle). The shading information may include modulation of at least one of color or brightness on one or more surfaces of the primitive. Primitive data may also include coordinate information for each of the primitives in a 3D coordinate system.

The display may include a number of display elements and the controller may include a number of computing units. Respective coordinate information for each of the display elements in the 3D coordinate system may be determined based on coordinate information for each of the list of primitives in the 3D coordinate system. For example, the distance between the display and the object corresponding to the primitive can be determined in advance. Based on the predetermined distance and the coordinate information of the primitive, coordinate information of the display element can be determined. Respective coordinate information for each of the display elements may correspond to a logical memory address of the element stored in memory. In that way, when the controller loops through the logical memory addresses of display elements within the controller's logical memory space, it can identify the corresponding actual physical location of the display element within the space.

The EM field contribution from each of the primitives to each of the display elements is determined (404) by calculating the propagation of the EM field from the primitives to the elements in a 3D coordinate system. The EM field contribution can include at least one of a phase contribution or an amplitude contribution.

As illustrated above with respect to FIGS. 3A-3C, at least one distance between the primitive and the display element may be determined based on coordinate information of each of the display elements and coordinate information of each of the primitives. can. In some cases, for each primitive, at least one distance is or may be calculated only once. For example, the controller may determine the distance between a first of the primitives and a first of the display elements based on the coordinate information of each of the first primitives and the coordinate information of each of the first elements. determining a first distance between the first primitive and a second of the elements based on the first distance and the distance between the first and second elements; 2 distances can be determined. The distance between the first element and the second element can be predetermined based on the pitch of the plurality of elements of the display.

The controller can determine an EM field contribution from the primitive to the display element based on a predetermined expression of the primitive and the at least one distance. In some cases, the predetermined expression can be determined by analytically calculating the EM field propagation from the primitive to the element, as illustrated above with respect to FIGS. 3A-3C. In some cases, the predetermined equations are determined by solving Maxwell's equations. In particular, Maxwell's equations can be solved by providing boundary conditions defined at the surface of the display. The boundary conditions can include Dirichlet boundary conditions or Cauchy boundary conditions. The primitives and display elements are in 3D space, and the surface of the display forms part of the boundary of the 3D space. The predetermined expression can include at least one of a function including a sine function, a cosine function, and an exponential function. During the calculation, the controller can identify the value of at least one of the functions in the table stored in memory, which can increase the speed of the calculation. The controller determines a first EM field contribution from the first primitive to the display element in parallel with determining a second EM field contribution from the second primitive to the display element. The EM field contribution to each of the display elements for each can be determined.

For each display element, a total EM field contribution from the list of primitives to the display element is generated (406).

In some implementations, the controller determines a first EM field contribution from the primitive to the first display element, sums the first EM field contribution for the first element, and sums the first EM field contribution from the primitive to the second display element. A second EM field contribution to the display element is determined and the second EM field contribution for the second display element is summed. The controller may include a number of computing units. The controller determines an EM field contribution from the first primitive to the first element by the first computing unit in parallel with determining an EM field contribution from the second primitive to the first element by the second computing unit. The EM field contribution of can be determined.

In some implementations, the controller determines a first respective EM field contribution from the first primitive to each of the display elements and a second respective EM field contribution from the second primitive to each of the display elements. Determine field contribution. The controller then accumulates the EM field contribution for the display element by adding the second respective EM field contribution to the first respective EM field contribution for the display element. In particular, the controller is configured to perform a first computing step in parallel with determining a second respective EM field contribution from the second primitive to each of the display elements by using the second computing unit. By using the unit, a first respective EM field contribution from the first primitive to each of the display elements can be determined.

A first control signal is transmitted to the display, the first control signal being for modulating at least one characteristic of each display element based on the sum of the field distributions to the display element (408). . The at least one property of the element includes at least one of refractive index, amplitude index, birefringence, or retardation.

The controller may generate a respective control signal for each of the display elements based on the sum of the EM field contributions from the primitives to the element. Each control signal is for modulating at least one property of the element based on the sum of the EM field contributions from the primitive to the element. That is, the first control signal includes respective control signals for the display elements.

In some examples, the display is controlled by electrical signals. Each control signal may then be an electrical signal. For example, LCOS displays include an array of microelectrodes whose voltages are individually controlled as element intensities. LCOS displays can be filled with a birefringent liquid crystal (LC) compound that changes its refractive index as the applied voltage changes. Accordingly, respective control signals from the controller can control the relative refractive index across the display elements, and thus the relative phase of light passing through or reflected by the display.

As discussed above, the display surface forms part of the interface. The controller multiplies the sum of field contributions of each of the elements by a scale factor to obtain a scaled sum of field contributions, and generates respective control signals based on the scaled sum of field contributions for the elements. be able to. In some cases, the controller normalizes the sum of the field contributions for each of the elements, e.g., among all the elements, and adjusts each control signal based on the normalized sum of the field contributions for the elements. can be generated.

The second control signal is transmitted to the illuminator as a control signal to turn on the illuminator to illuminate the modulated display (410). The controller can generate and transmit a second control signal in response to determining completion of obtaining a total field contribution for each of the display elements. Due to time symmetry (or conservation of energy), the modulated elements of the display can propagate light in different directions to form a volumetric light field that corresponds to an object in 3D space. The volume light field may correspond to a solution of Maxwell's equations with boundary conditions defined by the modulated elements of the display.

In some implementations, the illuminator is coupled to the controller through a memory buffer configured to control the amplitude or brightness of one or more light emitting elements within the illuminator. The memory buffer for the illuminator may have a smaller size than the memory buffer for the display. Some light emitting elements in the illuminator can be smaller than some elements of the display. The controller may be configured to simultaneously activate one or more light emitting elements of the illuminator.

In some examples, the illuminator includes two or more light emitting elements, each configured to emit light having a different color. the controller sequentially modulates the display with information associated with the first color during a first time period and modulates the display with information associated with the second color during a second consecutive time period; and a first light emitting element to emit light having a first color during a first time period, and a second light emitting element to emit light having a second color during a second time period. , can be configured to control the illuminator to turn on continuously. In this way, multicolored objects can be displayed in 3D space.

In some examples, the display has a resolution small enough to diffract light. The illuminator can emit white light that can cause the display to diffract the white light into light having different colors, thereby displaying multicolored objects.

Exemplary System FIGS. 5A-5K illustrate an exemplary system implementation for 3D display. Any one of the systems may correspond to system 100 of FIG. 1A, for example. 5A and 5B illustrate an exemplary system having a reflective display with front illumination. FIG. 5C shows an example system with a transmissive display with backlighting. 5D and 5E illustrate an example system having a transmissive display with waveguide illumination. 5F and 5G illustrate an exemplary system having a reflective display with waveguide illumination. 5H and 5I illustrate an exemplary system having a reflective display with optically diffractive illumination using a transmission grating structure (FIG. 5H) and a reflective grating structure (FIG. 5I). 5J and 5K illustrate an exemplary system having a transmissive display with optically diffractive illumination using a reflective grating structure (FIG. 5J) and a transmission grating structure (FIG. 5K).

FIG. 5A illustrates a system 500 with a reflective display with front illumination. System 500 includes a computer 502, a controller 510 (eg, an ASIC), a display 512 (eg, an LCOS device), and an illuminator 514. Computer 502 may be computing device 102 of FIG. 1A, controller 510 may be controller 112 of FIG. 1A, display 512 may be display 114 of FIG. 1A, and illuminator 514 may be computing device 102 of FIG. 1A. 116.

As illustrated in FIG. 5A, computer 502 includes an application 504 having a renderer 503 for rendering a scene of objects. Rendered scene data is processed by video driver 505 and then by GPU 506. GPU 506 may be GPU 108 of FIG. 1A and may be configured to generate a list of primitives corresponding to the scene and respective primitive data. For example, video driver 505 may be configured to process rendered scene data and generate a list of primitives. As mentioned above, GPU 506 may include a conventional 2D renderer, such as conventional 2D renderer 120 of FIG. 1A, for rendering primitives into a list of items to be drawn on 2D display 508. GPU 506 or controller 510 may include a holographic renderer, such as holographic renderer 130 of FIG. 1A, for rendering the list of primitives into graphics data displayed by display 512.

Controller 510 is configured to receive graphics data from computer 502, calculate the EM field contribution to each of the elements of display 512 from the list of primitives, and generate respective sums of EM field contributions from the primitives to each of the elements. It is composed of Controller 510 can generate a respective control signal to each of the display elements to modulate at least one characteristic of the display element. The controller may transmit respective control signals to display elements of display 512 through memory buffer 511 for display 512 .

Controller 510 can also generate and transmit control signals, such as illumination timing signals, to operate illuminator 514. For example, controller 510 may generate and transmit a control signal in response to determining that the calculation of the total EM field contribution from the primitive to the display element is complete. As discussed above, controller 510 may transmit control signals to illuminator 514 via a memory buffer. The memory buffer can be configured to control the amplitude or brightness of the light emitting elements within the illuminator 514 and to activate the light emitting elements simultaneously or sequentially.

As illustrated in FIG. 5A, the illuminator 514 can emit a collimated light beam 516 that is incident on the front surface of the display 512 at an angle of incidence ranging from 0 degrees to approximately ±90 degrees. The emitted light beam is diffracted from display 512 to form a holographic light field 518 corresponding to the object, which can be viewed by a viewer.

FIG. 5B illustrates another system 520 with another reflective display 524 with front illumination. Compared to system 500 of FIG. 5A, system 520 has a larger reflective display 524. To accommodate this, or for other packaging or aesthetic reasons, display controller 522 is included in a housing, which may be a support or enclosure for illuminator 526. Controller 522 is similar to controller 510 of FIG. 5A and receives graphics data from computer 521, calculates the EM field contribution from the primitives to each of the display elements of display 524, and calculates the EM field contribution from the primitives to each of the display elements. The respective sums of the field contributions may be configured to be generated. Controller 522 then generates and transmits a respective control signal to each of the display elements through memory buffer 523 for display 524 to modulate at least one characteristic of the display element. Transmit respective control signals.

Controller 522 also transmits control signals to illuminator 526 to operate illuminator 526. Illuminator 526 emits a diverging or semi-collimated light beam 527 to cover the entire surface of display 527. Light beam 524 is diffracted by modulated display 524 to form holographic light field 528.

FIG. 5C illustrates a system 530 with a transmissive display 534 with backlighting. Transmissive display 534 may be, for example, a large display. System 530 includes a controller 532 that may be similar to controller 510 of FIG. 5A. Controller 532 is configured to receive graphics data from computer 531, calculate EM field contributions from the primitives to each of the display elements of display 534, and generate respective sums of EM field contributions from the primitives to each of the display elements. It can be configured as follows. Controller 532 then generates a respective control signal to each of the display elements through memory buffer 533 for display 534 to modulate at least one characteristic of the display element. Transmit respective control signals.

Controller 532 also transmits control signals to illuminator 536 to operate illuminator 536. Unlike system 500 of FIG. 5A and system 520 of FIG. 5B, illuminator 536 in system 530 is positioned behind the back of display 534. To cover a large surface of display 534, illuminator 536 emits a diverging or semi-collimated light beam 535 at the back of display 534. Light beam 535 is transmitted through modulated display 534 and diffracted to form holographic light field 538.

FIG. 5D illustrates another system 540 with a transmissive display 544 with waveguide illumination. System 540 also includes a controller 542 and an illuminator 546. Controller 542 may be similar to controller 510 of FIG. 5A and receives graphics data from computer 541, performs calculations on the graphics data, generates control signals for modulation, and transmits to display 544. and can be configured to generate and transmit a timing signal to activate the illuminator 546.

Illuminator 546 can include a light source 545 and can include a waveguide 547 or be optically mounted. Light emitted from light source 545 can be coupled into waveguide 547, for example from a side section of the waveguide. Waveguide 547 is configured to direct light to uniformly illuminate the surface of display 544. Light guided by waveguide 547 is incident on the back side of display 544, transmitted through display 544, and diffracted by display 544 to form holographic light field 548.

Unlike system 500 of FIG. 5A, 520 of FIG. 5B, and 530 of FIG. 5C, in system 540, controller 542, display 544, and waveguide 547 are integrated together into a single unit 550. In some cases, waveguide 547 and light source 545 can be integrated as a planar form of active waveguide illuminator, which can further increase the degree of integration of single unit 550. can. As discussed above, a single unit 550 can be connected or tiled with other similar units 550 to form a larger holographic display device.

FIG. 5E illustrates another system 560 with another transmissive display 564 with waveguide illumination. Compared to system 540, transmissive display 564 can potentially implement a larger display than transmissive display 544. For example, transmissive display 564 can have a larger area than controller 562, and controller 562 can be positioned farther from display 564 to accommodate this. System 560 includes an illuminator 566 having a light source 565 and a waveguide 567. Waveguide 567 is integrated with display 564, eg, optically attached to the back of display 564. In some implementations, display 564 may be fabricated on the front side of the substrate and waveguide 567 may be fabricated on the back side of the substrate.

Controller 562 may be similar to controller 510 of FIG. and is configured to transmit to display 564 and generate and transmit a timing signal to activate light source 565 . Light emitted from light source 565 is directed in waveguide 567 to illuminate the backside of display 564 , is transmitted through display 564 , and is diffracted to form holographic light field 568 .

FIG. 5F illustrates another system 570 with a reflective display 574 with waveguide illumination. Reflective display 574 may be, for example, a large display. A waveguide 577 of illuminator 576 is positioned on the front surface of reflective display 574. A controller 572, similar to controller 510 of FIG. 5A, receives graphics data from computer 571, performs calculations on the graphics data, and generates control signals for modulation to display 574 through memory buffer 573. , and may be configured to generate and transmit a timing signal to activate the light source 575 of the illuminator 576. Light coupled from waveguide 577 of illuminator 576 is directed to be incident on the front surface of display 574 and is diffracted by display 574 to form holographic light field 578 .

FIG. 5G illustrates another system 580 with a reflective display 584 having another type of waveguide illumination using a waveguide device 588. A controller 582, similar to controller 510 of FIG. 5A, generates and transmits control signals corresponding to holographic data (images and/or video) for modulation of a display 584 and transmits timing signals for illumination. 586. Illuminator 586 can provide one or more colors of light that can be collimated. Waveguide device 588 is positioned in front of illuminator 586 and display 584. Waveguide device 588 may include an input coupler 588-1, a waveguide 588-2, and an output coupler 588-3. Input coupler 588-1 is configured to couple collimated light from illuminator 586 into waveguide 588-2. The light then travels within waveguide 588-2 via total internal reflection and enters output coupler 588-3 at the end of waveguide 588-2. Output coupler 588-3 is configured to couple and output light to display 584. The light then illuminates a display element of display 584 that is modulated with a corresponding control signal, is diffracted by reflective display 584, and passes through waveguide device 588 (e.g., output coupler 588-3) (e.g., (by the rearview mirror of display 584) to form a holographic light field corresponding to holographic data in front of the viewer.

In some examples, light is coupled by output coupler 588-3 to the front surface of waveguide device 588 and/or reflective display 584 at a normal angle. In some examples, each of input coupler 588-1 and output coupler 588-2 can include a grating structure, eg, a Bragg grating. Input coupler 588-1 and output coupler 588-2 can include similar gratings with different fringe tilt angles. In some examples, illuminator 586 provides monochromatic light and input coupler 588-1 and output coupler 588-2 include colored gratings. In some examples, illuminator 586 provides light beams of multiple colors, e.g., red, green, and blue, and input coupler 588-1 and output coupler 588-2 provide light beams of different colors. may include a multilayer stack of three corresponding gratings (or a single layer with three corresponding gratings) each having a coupled input or a coupled output.

FIG. 5H illustrates another system 590 with a reflective display 594 having optical diffractive illumination using an optical diffractive device 598. Optical diffraction device 598 can be considered a light guide device for guiding light. Optical diffraction device 598 can be a transmission field grating-based structure that can include one or more transmission holographic gratings. Reflective display 594 may be a reflective LCOS device. A controller 592, similar to controller 510 of FIG. 5A, receives graphics data corresponding to one or more objects from computer 591, performs calculations on the graphics data, generates control signals for modulation, and memory The signal may be configured to be transmitted through a buffer 593 to a display 594 . Controller 592 is also coupled to illuminator 596 and can be configured to provide timing signals to operate illuminator 596 to provide light. The light is then diffracted by optical diffraction device 598 and incident on display 594, which in turn is diffracted by display 594 to form a holographic light field 599 corresponding to one or more objects. Display 594 can include a rearview mirror at the rear of display 594 to reflect light toward the viewer. Optical diffraction device 598 can be optically transparent. The illuminator 596 can be positioned below the display 594, allowing the illuminator 596 to be mounted or housed with other components of the system 590 and below the viewer's line of sight. do.

As discussed in more detail below, Bragg selectivity allows off-axis illumination light to be diffracted from optical diffraction device 598 towards display 594, while off-axis illumination light is diffracted back from display 594. The light can be close to the axis and thus be off-Bragg with respect to the grating of optical diffraction device 598 and thus pass through optical diffraction device 598 without being diffracted again by the grating of optical diffraction device 598. You can pass it almost completely and move on to the viewer. In some implementations, the light from the illuminator 596 can be incident on the optical diffractive device 598 at a large angle of incidence from the side of the display 594, so that the illuminator 596 does not obstruct the viewer's view and It does not invade the graphic light field 599. The angle of incidence can be a positive or negative angle relative to the normal to display 594. For illustration purposes, the angle of incidence is presented as a positive angle. For example, the angle of incidence may be in the range of 70 degrees to 90 degrees, such as in the range of 80 degrees to 90 degrees. In a particular example, the angle of incidence is 84 degrees. The diffracted light from the optical diffractive device 598 allows the light to uniformly illuminate the display 594, minimizing power loss due to undesired reflection, diffraction, and/or scattering in or at the surface of the optical diffractive device 598. It can be diffracted at near normal incidence to the display 594 such that it can be diffracted at near normal incidence to the display 594 so that it can be diffracted back through the optical diffraction device 598 almost perpendicularly to the viewer's eye. In some examples, the diffraction angle from optical diffraction device 598 to reflective display 594 is between -10° (or 10 degrees) and 10° (or 10 degrees), such as between -7° and 7°, or 5°. It can be in the range of ~7°. In a particular example, the diffraction angle is 6°. In another example, the diffraction angle is 0°.

In some implementations, as illustrated in FIG. 5H, the optical diffraction device 598 is positioned in front of the reflective display 594, eg, along the Z direction toward the viewer. Optical diffraction device 598 can include a field grating structure 598-1 positioned on substrate 598-2. The back side of field grid structure 598-1 faces the front side of reflective display 594, and the front side of field grid structure 598-1 is attached to substrate 598-2. Light from illuminator 596 can be incident, for example, from the side of substrate 598-2, through substrate 598-2, and onto the front surface of field grating structure 598-1. For example, the substrate 598-2 can have wedge-shaped sides, such as illustrated in further detail in FIG. 12C, so that light at large angles of incidence has less reflection loss. Can be done.

As discussed in more detail below, if the diffraction efficiency of a diffractive structure, e.g. a holographic grating, is less than 100%, then light incident at a certain angle of incidence can be diffracted by the diffractive structure to the zero and first orders. can. The first order light (or primary light) is diffracted again by the diffractive structure at the angle at which it was diffracted towards the display, reconstructing the holographic light field 599. The first order may also be referred to as the first diffraction order. The zeroth order light (or zeroth order light, or undiffracted light, or undiffracted order) is undiffracted (or unpolarized) by the diffractive structure and transmitted by the diffractive structure at an angle corresponding to the angle of incidence. Zero order light can cause undesirable effects such as ghost images, for example, when the zero order light is incident on reflective display 594 directly or following reflection from a surface within optical diffraction device 598.

Field grating structure 598-1 can be spaced apart from display 594 to eliminate undesirable effects. In some implementations, the back side of field grid structure 598-1 is separated from the front side of display 594 by a gap. The gap can have any suitable distance, for example 1 mm. The gap can be filled with air or any low index material to satisfy total internal reflection (TIR) on the interface. For example, air has a refractive index of the back layer of field grating structure 598-1 (e.g.,
) is much smaller than the refractive index (e.g.
), and therefore any afterglow at an angle of incidence (e.g. >70°) will have an angle of incidence of critical angle (e.g.
in the case of,
), it can be completely internally reflected by the back surface of field grating structure 598-1. That is, incident angle afterglow cannot reach the reflective display 594, causing undesirable effects. In some examples, at least one of the front side of reflective display 594 or the back side of field grating structure 598-1 is treated with an anti-reflective coating, which prevents holographic light reflected from reflective display 594. A portion of the field can be significantly reduced backwards from behind the field grating structure 598-1 toward the reflective display 594, which could otherwise cause further ghost images. In some examples, the back side of field grid structure 598-1 can be protected by an additional layer, eg, a glass layer.

In some implementations, instead of being separated by a gap, the back side of field grating structure 598-1 can be attached to the front side of reflective display 594 using an interlayer. The intermediate layer may be an optically clear adhesive (OCA) layer having a refractive index substantially lower than that of the back layer of field grating structure 598-1 such that total internal reflection (TIR) may occur. , the remaining zero-order light can be completely reflected back into the optical diffraction structure 598 at the interface between the intermediate layer and the back layer of the field grating structure 598-1.

In some implementations, field grating structure 598-1 and display 594 can be separated by a gap so that any afterglow cannot reach display 594. The gap can be filled with any suitable transparent material, index matching fluid, or OCA. In some implementations, field grating structure 598-1 can be formed within a cover layer (eg, a cover glass) of display 594.

In some cases, the active area of field grating structure 598-1 is configured to illuminate the entire surface of reflective display 594 by light diffracted from the active area of field grating structure 598-1. It does not have to be smaller than the area of the entire surface. In some implementations, field grating structure 598-1 and reflective display 594 have a rectangular shape with a height along the X direction and a width along the Y direction. The active area of field grating structure 598-1 can have a height not less than the height of reflective display 594 and a width not less than the width of reflective display 594. If there is a substantial gap between the field grating structure 598-1 and the reflective display 594, the field grating structure 598-1 and the substrate 598-2 will provide an expanded cone (or truncated cone) of light from the reflective display 594. ), for example, the holographic light field 599 can be further expanded so that it can be seen through the front surface of the optical diffraction device 598 (around the +Z axis) over the entire vertical and horizontal field of view of the holographic light field 599. Substrate 598-2 can be slightly wider and taller than field grating structure 598-1.

Because the light is incident on the field grating structure 598-1 at a substantially off-axis angle in a certain dimension, eg, the Z direction, the light may become narrower by the cosine of the angle of incidence in that dimension. Light from illuminator 596 can have a narrow rectangular shape incident on field grating structure 598-1, which can then expand the light into a larger rectangular shape incident on reflective display 594. One or more optical components, such as mirrors, prisms, optical slabs, and/or optical fillers, may be used to further expand the light and filter its bandwidth, including the illuminator 596, optical diffractive structure 598, and It can be placed between and within reflective displays 594. In some examples, the expanded light is larger than the active area of the reflective display 594 such that the edges and surrounding areas of the illuminated area of the reflective display 594 are less noticeable in reflections or scattering toward the viewer. Can have a slightly smaller beam area. In some examples, the expanded light may overlap the edges of the illuminated area of the reflective display 594 even though the edges of the expanded light may not be uniform, e.g. due to diffraction from masking edges. The beam area can be slightly larger than the active area of the reflective display 594 so that the entire area is completely illuminated.

In some implementations, the controller 592 obtains graphics data including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space and displays a reflective display 594 for each of the plurality of primitives. determining, for each of the plurality of display elements, a sum of EM field contributions from the plurality of primitives to the display element; For each of the display elements, a respective control signal may be generated based on the sum of the EM field contributions to the display element.

In some implementations, the illuminator 596 includes one or more colored light emitting elements configured to emit light of a corresponding color, e.g., red, blue, or green lasers (or LEDs). be able to. Optical diffraction device 598 can be configured to diffract a plurality of different colors of light at respective diffraction angles that are substantially the same as each other. Each of the respective diffraction angles ranges from 0° to ±10°, for example 0°, + or -1°, + or -2°, + or -3°, + or -4°, + or -5°. °, + or -6°, + or -7°, + or -8°, + or -9°, or + or -10°.

In some implementations, controller 592 is configured to sequentially modulate display 594 with information associated with multiple colors of light within a series of time periods. For example, the information may include a series of color holograms or images. The controller 592 can control the illuminator 596 to sequentially emit each of the plurality of colors of light to the optical diffraction device 598 during each of the series of time periods, thus emitting the plurality of colors of light. are diffracted by an optical diffraction device 598 onto a reflective display 594 and by a modulated display element of the reflective display 594 to form a respective color three-dimensional holographic image corresponding to the object during each period. A light field 599 is formed. Depending on the temporal coherence of the visual effects in the viewer's eyes, multiple colors can be combined in the eye to give a full color appearance. In some cases, the illuminator 596 is used during black insertion subframes between color subframes, during video source blanking or retrace periods, or during LC rise, fall, or DC balancing inversion transitions, or during system warm-up. , or if the intended holographic light field is completely black, or during a change of state of the display image (or holographic reconstruction), such as during a calibration procedure, the different light emitting elements are switched off and activated. Once the image (or holographic reconstruction) has been presented for a certain period of time, it is turned on. It can also rely on persistence of vision to ensure that the image (or holographic reconstruction) appears stable and flicker-free.

If a portion of holographic light field 599 appears in front of display 594, as illustrated by light field 599-1 in FIG. It is the actual part of a holographic reconstruction (also called real image or real holographic reconstruction). When the viewer looks at a light spot in front of display 594, there is actually light being reflected from display 594 to that point. If a portion of light field 599 appears to be behind (or within) display 594, as illustrated by light field 599-2 in FIG. 5H, that portion of holographic light field 599 is The virtual part of the constructed image or holographic reconstruction (also called virtual image or virtual holographic reconstruction). When a viewer looks at a light spot that appears to be behind or within display 594, there is actually no light being diffracted from display 594 to that virtual spot, but rather a fraction of the light diffracted from display 594. appears to occur at that virtual point.

Computer 591 and/or controller 592 coordinates the calculation (e.g., by equations) of information (e.g., a two-dimensional hologram, image, or pattern) to be modulated in display 594 to generate a reconstructed holographic light field 599 can be configured to move back and forth along a direction perpendicular to display 594 (eg, the Z direction). The calculation can be based on a holographic rendering process, for example, as illustrated in FIGS. 2 and 3A-3G. In some cases, holographic light field 599 may be completely in front of display 594. In some cases, holographic light field 599 may appear to be entirely behind display 594. In some cases, as illustrated in FIG. 5H, the holographic light field includes a portion in front of the display 594, such as the actual portion 599-1, and another portion that appears to be behind the display. , for example, may have a virtual portion 599-2. That is, the light field 599 can appear to span the surface of the display 594, which can be referred to as image planning.

Optical diffraction device 598 can be implemented in different configurations. In some implementations, the optical diffraction device 598 includes a holographic grating, e.g., a Bragg grating, for a particular color, e.g., as illustrated in FIGS. 7A, 7B, and 8, and the holographic light field 599 can correspond to a specific color. In some implementations, optical diffraction device 598 includes multiple holographic gratings for different colors in a single recording layer, as illustrated in FIGS. 7C, 7D, and 7E, for example.

In some implementations, optical diffraction device 598 includes multiple holographic gratings for different colors in different recording layers, as illustrated in FIGS. 9A-12C, for example. As illustrated in Figure 7F, a grating of a certain color can diffract not only light of a certain color but also light of other colors, which causes crosstalk between different colors. there is a possibility. In some examples, as described in further detail below with respect to FIGS. 9A-10B, the optical diffractive device 598 includes one or more optical diffractive devices for suppressing (e.g., eliminating or minimizing) color crosstalk. A plurality of holographic gratings having color selective polarizers as described above may be included. In some examples, as described in more detail below with respect to FIGS. 11-12C, the optical diffraction device 598 includes a filter for different colors incident at respective angles of incidence to suppress color crosstalk and zero-order light. A plurality of holographic gratings having one or more reflective layers for light can be included. In some examples, optical diffraction device 598 includes one or more color-selective polarizers, such as illustrated in FIGS. 9A-10B, to suppress color crosstalk and zero-order diffraction, and As illustrated in FIGS. 11-12C, multiple holographic gratings with one or more reflective layers can be included. Each of the color selective polarizers can be configured for a single color or multiple colors. Each of the reflective layers can be configured for a single color or multiple colors.

FIG. 5I illustrates another system 590A with a reflective display 594A having optical diffractive illumination using an optical diffractive device 598A. Reflective display 594A may be the same as reflective display 594 of FIG. 5H. Unlike optical diffraction device 598 of system 590 of FIG. 5H, optical diffraction device 598A of system 590A has a reflection field grating-based structure that can include a reflection field grating structure 598-1A and a substrate 598-2A. Substrate 598-2A may be a glass substrate. Reflection field grating structure 598-1A may include one or more reflection holographic gratings for one or more different colors. Reflection field grating structure 598-1A is disposed on the front surface of substrate 598-2A, for example along the Z direction. Illuminator 596 is positioned behind reflected field grating structure 598-1A and is configured to illuminate reflected field grating structure 598-1A at a large angle of incidence. The light is diffracted backwards (along the Z direction) against reflective display 594A, which further diffracts the light backwards through optical diffraction device 598A to form holographic light field 599.

FIG. 5J illustrates another system 590B with a transmissive display 594B having optical diffractive illumination using an optical diffractive device 598B. Transmissive display 594B may be the same as transmissive display 534 of FIG. 5C, 544 of FIG. 5D, or 564 of FIG. 5E. Similar to optical diffractive structure 598A of FIG. 5I, optical diffractive structure 598B can be a reflective field grating-based structure that can include a reflective field grating structure 598-1B and a substrate 598-2B. Substrate 598-2B may be a glass substrate. Reflection field grating structure 598-1B can include one or more reflection holographic gratings for one or more different colors. Unlike optical diffractive structure 598A of FIG. 5I, reflected field grating structure 598-1B within optical diffractive structure 598B is located on the back side of substrate 598-2B. Illuminator 596 is positioned in front of reflected field grating structure 598-1B and is configured to illuminate reflected field grating structure 598-1B at a large angle of incidence. The light is diffracted backwards (along the Z direction) to the transmissive display 594B, which further diffracts the light to form a holographic light field 599.

FIG. 5K illustrates another system 590C with a transmissive display 594C having optical diffractive illumination using an optical diffractive device 598C. Transmissive display 594C may be the same as transmissive display 594C of FIG. 5J. Similar to optical diffractive structure 598 of FIG. 5H, optical diffractive structure 598C can be a transmission field grating-based structure that can include transmission field grating structure 598-1C and substrate 598-2C. Substrate 598-2C may be a glass substrate. Transmission field grating structure 598-1C can include one or more transmission holographic gratings for one or more different colors. Unlike the optical diffractive structure 598 of FIG. 5H, the transmission field grating structure 598-1C within the optical diffractive structure 598C is located on the front surface of the substrate 598-2C. Illuminator 596 is positioned behind transmission field grating structure 598-1C and is configured to illuminate transmission field grating structure 598-1C at a large angle of incidence. The light is diffracted forward (along the +Z direction) to the transmissive display 594C, which further diffracts the light to form a holographic light field 599.

As discussed above, FIGS. 5H-5K illustrate different combinations of reflective/transmissive displays and field gratings based on reflective/transmissive optical diffraction devices. In some cases, placing the optical diffraction device on the back side of the display is a better choice for photopolymers, if they are not already protected by their inherent structure or by an additional glass layer. can provide protection. In some cases, the transmission grating may be mechanically and optically close to the display, and light from the transmission grating to the display can travel a shorter distance than from the reflection grating, which may be due to alignment , coverage, dispersion, and/or scattering problems can be reduced. In some cases, transmission gratings can have larger wavelength tolerances and smaller angular tolerances than reflection gratings. In some cases, the transmission grating may be less likely to mirror ambient illumination toward the viewer, such as ceiling lights and illuminated keyboards. In some cases, a transmissive display allows a viewer to be close to the display, and a holographic light field can be projected close to the display. In some cases, for transmissive displays, the transmissive display glass substrate has proven manufacturing capabilities up to >100 inches diagonally with near-seamless tiling for movie theater and architectural sizes. Can be done. In some cases, reflective and transflective displays may embed a controller, e.g. a Maxwell holography circuit, behind the display element, and transmissive displays may embed a controller, e.g. a Maxwell holography circuit, behind the display element; A controller or circuit can be integrated at the rear. In some cases, reflective and transflective displays may allow light to make a double pass through the display element (e.g., liquid crystal material), whereas transmissive displays use a single pass through the liquid crystal material; It is possible to have twice the rate change. A transflective display can refer to a display that has an optical layer that reflects transmitted light.

Exemplary Display Implementations As mentioned above, the display in Maxwellian holography can be a phase modulation device. A phase element (or display element) of a display can be represented as a phasel. For purposes of example only, a liquid crystal on silicon (LCOS) device will be discussed below to function as a phase modulation device. LCOS devices are displays that use a liquid crystal (LC) layer on top of a silicon backplane. LCOS devices can be optimized to achieve the smallest possible phasel pitch, the smallest crosstalk between phasers, and/or the largest available phase modulation or delay (eg, at least 2π).

A list of parameters can be controlled to control the birefringence of the LC mixture (Δn), the cell gap (d), the dielectric anisotropy of the LC mixture (Δε), the rotational viscosity of the LC mixture (η), and the silicon backplane and LC layers. The performance of the LCOS device can be optimized, including the maximum applied voltage (V) between the electrode and the common electrode.

There may be fundamental trade-offs that exist between the parameters of liquid crystal materials and structures. For example, a fundamental boundary parameter is the available phase modulation or delay (Re), which is
Re=4π・Δn・d/λ(8)
It can be expressed as,
where λ is the wavelength of the input light. For red light with a wavelength of about 0.633 μm, if the delay Re needs to be at least 2π,
Δn ・d ≧ 0.317 μm (9).
The above equation means that for any given wavelength (λ), there is a direct trade-off between the cell gap (d) and birefringence (Δn) of the LC mixture.

Another boundary parameter is the switching speed, or switching time (T), taken by the LC molecules in the liquid crystal (LC) layer to reach the desired orientation after a voltage is applied. For example, for real-time video (approximately 60 Hz) using a three-color field continuous color system, a minimum 180 Hz modulation of the LC layer is involved, which places an upper limit on the LC switching speed of 5.6 milliseconds (ms). Switching time (T) is related to several parameters including liquid crystal mixture, cell gap, operating temperature, and applied voltage. First, T is proportional to ^d2 . As the cell gap d decreases, the switching time decreases according to the square. Second, the switching time is also related to the dielectric anisotropy (Δε) of the liquid crystal (LC) mixture, with higher dielectric anisotropy leading to shorter switching times and lower viscosity (temperature-dependent ) also results in shorter switching times.

The third boundary parameter may be a fringing field. Due to the high electron mobility of crystalline silicon, LCOS devices can be fabricated with very small phasel sizes (eg, less than 10 μm) and submicron interphasel gaps. When adjacent phasels are operated at different voltages, the LC director near the phasel edge is distorted by the lateral components of the fringing field, which significantly degrades the electro-optical performance of the device. Additionally, when the fasel gap becomes comparable to the wavelength of the incident light, diffraction effects can cause severe optical losses. To maintain phase noise within acceptable levels, the phasel gap may need to be kept below the phasel pitch.

In some examples, the LCOS device is designed to have a 2 μm fazel pitch and a cell gap of about 2 μm when fringe field boundary conditions are observed. According to the above formula Δn·d≧0.317 μm, Δn needs to be greater than or equal to 0.1585, which is achievable using current liquid crystal technology. Once the minimum birefringence for a given phasel pitch is determined, the LC is optimized for switching speed, e.g. by increasing dielectric anisotropy and/or decreasing rotational viscosity. be able to.

Non-Uniform Phasel Implementation for Displays In LCOS devices, a circuit chip, such as a complementary metal oxide semiconductor (CMOS) chip or equivalent, controls the voltage of a reflective metal electrode embedded beneath the chip surface. , each controlling one phasel. The common electrode of all phasers is provided by a transparent conductive layer made of indium tin oxide on the LCOS cover glass. The feathers can have the same size and the same shape (eg, square). For example, a chip can have 1024x768 (or 4096x2160) phasels, each with independently addressable voltages. As mentioned above, when the interphasel gap becomes comparable to the wavelength of the incident light, a diffraction effect may appear due to the periodic structure of the LCOS device, which results in a large optical loss and a high intensity of the diffracted light. This can give rise to periodic structures.

In Maxwellian holographic computation, each phasel receives the sum of the EM contributions from each primitive and is relatively independent of each other. Therefore, the phasers of LCOS devices in Maxwell holography can be designed differently from each other. For example, as illustrated in FIG. 6A, an LCOS device 600 can be fabricated with several non-uniform (or irregular) phasels 602. At least two phasers 602 have different shapes. The non-uniform shape of the phasel 602 can significantly reduce or eliminate diffraction anomalies (eg, due to the periodic structure of the diffracted light), among other effects, thus improving image quality. Although the phasel can have a non-uniform shape, the phasel can be designed to have a size distribution with an average (eg, about 3 μm) that meets the desired spatial resolution. The silicon backplane can be configured to provide respective circuitry (eg, including metal electrodes) for each of the phasers according to the shape of the phaseles.

In a series of phasers in an LCOS device, to select a particular phasel, a first voltage is applied to a word line connecting a row of phasels that includes the particular phasel, and a first voltage is applied to a word line that connects the series of phasels that includes the particular phasel. A second voltage is applied to the bit line. Since each phasel has resistance and/or capacitance, the operating speed of the LCOS device can be limited by the switching (or rise and fall times) of these voltages.

As mentioned above, in Maxwellian holography, the phasels can have different sizes. As illustrated in FIG. 6B, LCOS device 650 is designed with one or more phasels 654 having a larger size than other phaseles 652. All of the phasels can still have a size distribution that meets the desired resolution. For example, 99% of the phasels have a size of 3 μm and only 1% of the phasels have a size of 6 μm. The larger size of phasel 654 allows at least one buffer 660 to be placed within phasel 654 in addition to other circuitry similar to phasel 652. Buffer 660 is configured to buffer the applied voltage so that the voltage is only applied to a smaller number of phasels within a row or column of phasels. The buffer 660 may be an analog circuit, for example made of transistors, or a digital circuit, for example made of several logic gates, or any combination thereof.

For example, as illustrated in FIG. 6B, one voltage is applied to word line 651 and another voltage is applied to bit line 653 to select a particular phasel 652*. Phasel 652* is in the same row as larger phasel 654, which includes buffer 660. Voltage is primarily applied to the first number of phasels in the column and before the larger phasel 654 and is interrupted by a buffer 660 within the larger phasel 654 . In such a manner, the operating speed of LCOS device 650 can be increased. With larger size phasels 654, other circuitry may also be placed within the LCOS device 650 to further improve the performance of the LCOS device 650. The feathers 654 and 652 of FIG. 6B have a square shape, and the feathers also have one or more feathers 654 having a larger size than other feathers 652, as illustrated in FIG. 6A. However, they can also have different shapes.

Exemplary Calibration The unique properties of Maxwell holography in this disclosure allow for the preservation of calibration techniques that can create a significant competitive advantage in the actual production of high quality displays. Several calibration techniques can be implemented in combination with Maxwellian holographic calculation techniques, including:
(i) using an image sensor or optical field sensor in conjunction with a Dirichlet boundary condition modulator and/or in conjunction with mechanical and software diffractive and non-diffractive calibration techniques;
(ii) software alignment and calibration, including individual color calibration and alignment with the Dirichlet boundary condition modulator; and (iii) incorporating light detection (including power and color) and/or temperature measurements directly into the modulator. Embedding silicon features into boundary condition modulators that, when combined with Maxwell holography, creates a powerful and unique approach to simplifying the manufacturing calibration process.

In the following, for purposes of example only, three types of calibration are implemented for phase-based displays, e.g. LCOS displays. Each phase element can be represented as a phasel.

Phase Calibration The amount of phase added to the light impinging on the LCOS phase element (or phasel) can be directly determined by the voltage applied to the LCOS phasel. This is because a birefringent liquid crystal (LC) rotates in the presence of an electric field, thus changing its index of refraction, slowing down the light and changing its phase. The changed phase can depend on the electrical properties of the liquid crystal (LC) and the silicon device in which the LC resides. The digital signals sent to the LCOS need to be converted to the correct analog voltages to achieve high quality holographic images. Phase calibration involves the LCOS device ensuring that digital signals are properly converted to analog signals applied to the LC to produce the maximum amount of phase range. This transformation is expected to result in linear behavior. That is, if the voltage changes in fixed increments, the phase will also change in fixed increments, regardless of the starting voltage value.

In some cases, LCOS devices allow users to modify a digital-to-analog converter (DAC) to control the amount of analog voltage output given a digital input signal. . A digital potentiometer can be applied to each input bit. For example, if there are eight input bits, there may be eight digital potentiometers corresponding to each input bit. The same digital input from the digital potentiometer can be applied to all phasers of the LCOS device. A bit set to ``1'' activates the voltage and a bit set to ``0'' does not activate the voltage. All voltages from such "1" bits are summed to obtain the final voltage sent to each phasel. There may also be a DC voltage applied in all cases such that all '0' bits result in a baseline non-zero voltage. Therefore, phase calibration of an LCOS device can be implemented by setting the value of a digital potentiometer of the LCOS device. For example, as described above, the controller calculates the EM field contribution to each of the display's phasels from the list of primitives, generates respective sums of the EM field contributions from the primitives to each of the phasels, and determines the phase of the phasels. A respective control signal to each of the phasers can be generated for modulation. The same digital input from the digital potentiometer can be applied to adjust respective control signals to all of the phasels of the LCOS device, which is different from phase calibration on a per-phasel basis. The digital input can be set once during the operation of the LCOS device, for example to display a hologram.

To determine the optimal set of phase calibration values for a digital input, a genetic algorithm can be applied, where there are many input values that lead to one output value, such as phase range or holographic image contrast. can. This output value can be reduced to a single number called fitness. Genetic algorithms can be configured to explore different combinations of input values until achieving the most compatible output. In some cases, an algorithm takes two or more of the most fitting inputs and combines a number of their constituent values together to have the characteristics of the captured input, but You can create new inputs that are different from each of the . In some cases, the algorithm may change one of these configuration values to something other than from any of the adapted inputs taken, this is denoted as a "transformation", and the available You can add various things to the matching input. In some cases, one or more optimal values are determined by making use of knowledge gained from previous measurements with good results, while trying new values so that the optimal value is not limited to local maxima. be able to.

There may be multiple ways to calculate the suitability output value. One method is to calculate the phase change of the light assuming a set of digital inputs applied to all phasels on the LCOS. With this method, incident light can be polarized. Upon impinging on the LCOS, the polarization of the incident light can change depending on the rotation of the LC. The incident light can be diffracted back through another polarizer set either to the same polarization or 90 degrees different from the original polarization and then incident on the photodetector. Therefore, as the LC rotation changes, the intensity seen by the photodetector can change. Therefore, phase changes in light can be perceived indirectly through intensity fluctuations. Another method to calculate the phase change is to measure the intensity difference of the Maxwellian holographic reconstruction from the background. This is most effective with projection displays. Measuring the intensity in such an example may require using a computer vision algorithm to identify the Maxwellian holographic reconstruction and measure its intensity. Another method for determining phase changes is to measure or image microscopically in an interferometric optical geometry.

Alignment Calibration Light sources and other optical elements may not be properly aligned within the holographic device and may need to be aligned. Different liquid crystals (LC) and optical diffractive or diffractive optical elements can also behave differently towards different wavelengths of the light source. Additionally, LCs, diffractive agents, and light sources, among others, degrade the device mechanically over time (aging and burn-in), as well as due to changes in the operating environment, such as operating temperature, and thermal or mechanical stress. As a result of the induced deformation, it can change, giving the same input hologram different properties, e.g. object scaling, when shown with different base colors or at different times or in different environments. Furthermore, certain hardware features may apply different optical effects, such as lens effects, to the output light, which may also require correction under these circumstances.

In some implementations, the above issues may be addressed by applying mechanical translations, deformations, and rotations to one or more optical elements. In some implementations, the above problem may be addressed by applying a mathematical transformation to the phase calculated for the display's phasel. The phase is the sum of each EM field contribution to the phasel from the list of primitives. Mathematical transformations can be derived from mathematical equations, such as Zernike polynomials, and can be varied by changing polynomial coefficients or other varying input values. The mathematical transformation can vary not only by color but also by phase. For example, there are Zernike polynomial coefficients that correspond to the amount of tilt applied to the light after it is diffracted from the display.

To determine these coefficients/input values, a 2D camera, photometer, light field camera, and/or other luminosity or colorimeter is used, illuminated by the LCOS in the case of a projection display, or illuminated by the LCOS in the case of a direct view display. Hardware and software setups can be created for reflective or diffusely transmitting surfaces, in some cases for LCOS. One or more holographic test patterns and objects can be transmitted to a display and measured by one meter or multiple meters. A 2D or 3D (light field) camera or camera array can use machine vision algorithms to determine what is being displayed and then calculate its suitability. For example, if a grid of dots is a test pattern, conformance is determined by how close they are, how centered they are in their intended location, how much distortion they have (e.g. scale or This can be determined by a statistical measure such as whether it shows a pincushion. There may be different suitability values for different performance characteristics. Depending on these values, corrections are applied, e.g. in the form of coefficient changes to the Zernike polynomials, until the fitness reaches a predetermined satisfaction level or passes a visual or task-oriented A/B test. can do. These test patterns can be rendered at different distances to ensure that the alignment is consistent, especially for one 3D point or plane, but also for objects at different distances. Such depth-based calibration can involve an iterative process involving changing the depth of the holographic test pattern or elements therein and the position of reflective or diffusely transmitting surfaces, can be iterated until convergence to a solution that works at multiple depths. Finally, a white dot can be displayed to indicate the validity of the calibration.

Color Calibration For displays, holographic, or otherwise, if any two units are rendering the same image, the colors will match between displays, and furthermore, the Rec. It is important that the colors match those defined by television (TV) and computer display standards, such as the G.709 standard or the sRGB color space of computer monitors. Hardware components of different batches, such as LEDs and laser diodes, can exhibit different behavior for the same input and can output different colors when perceived by the human eye. Therefore, it is important to have a color standard to which all display units can be calibrated.

In some implementations, the objective measurement of color specified by intensity and chromaticity measurements can be obtained by measuring color intensity against a Commission internationale de l'eclairage (CIE) standard observer curve. . Selected CIE The color output of a device within a color space can be objectively defined. Any deviation of the measured value from a known good value can be used to adapt the output color on the display back into alignment or fit, using an iterative measure-adapt-measure feedback loop. It can be implemented using Once the Maxwell holographic device produces an accurate output for a given set of inputs, the final adaptation is to create a lookup table for the illuminator that maps the input values to output intensities, and outputs the input color. It can be encoded as a color matrix transformation that converts to color space values. These calibration tables can be embedded in the device itself to produce reliable and objective output colors. Multiple such tables may be provided for each of multiple operating temperature ranges. Multiple such tables may be provided for each of a number of different regions of the active surface of the LCOS. Calibration values can be interpolated between tables of adjacent temperature ranges and/or adjacent surface areas.

In addition, tristimulus illumination (e.g., a linear mixture of red, green, and blue) may not be required, assuming an LCOS device with sufficiently fine features to control diffraction with subwavelength precision; LCOS devices are tristimulus, quadristimulus, or quadristimulus, which can be illuminated with a single broad-spectrum light source and combined with a spatial dithering pattern to reproduce a more complete spectral output of color rather than the common tristimulus approximation. Furthermore, the phase output can be selectively adjusted to produce N stimulus output colors. Assuming a sufficiently broad-spectrum illuminator, this means that Maxwell holography can be used for any signal that lies inside the spectral focus of the human visual system, or outside the spectral focus of infrared (IR) or ultraviolet (UV) structured light. Allows to generate reflected colors.

Exemplary holographic gratings of FIGS. 7A-7F may be included in an optical diffraction device (or light guide device), such as optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 5K. 1 illustrates an exemplary holographic grating implementation that can be used. 7A and 7B illustrate recording and reproducing a holographic grating in a recording medium in a single color. FIGS. 7C and 7D illustrate recording three different colors of holographic gratings in a recording medium with three different colors of light (FIG. 7C) and reproducing them with a single color of light (FIG. 7D) Illustrate. 7E and 7F illustrate reproducing three different colored holographic gratings in a recording medium with three different colored lights, and FIG. 7F illustrates color crosstalk between different colored diffracted lights. Illustrate. Any one of the recording reference light beam, the recording object light beam, the reproduction reference light beam, and the diffracted light beam is a polarized beam that can be s-polarized or p-polarized.

FIG. 7A illustrates an example of recording a holographic grating on a recording medium. The recording medium may be a photosensitive material, such as a photopolymer or photopolymer, silver halide, or any other suitable material. The recording medium can be arranged on a substrate, for example a glass substrate. The substrate may or may not be transparent during recording. In some implementations, the photosensitive material can be adhered to a carrier film, such as a TAC (triacetate cellulose) film. A photosensitive material with a carrier film can be laminated onto the substrate with the photosensitive material between the carrier film and the substrate.

In transmission holography, a recording reference beam and a recording object beam are incident on the same region of the recording medium from the same side, with a recording reference angle θ _r and a recording object angle θ _o , respectively. Each of the reference and object beams may start in air, pass through the photosensitive material, then pass into and through the substrate, and exit into air. The recording reference beam and the recording object beam have the same color, eg green, and the same polarization state, eg s-polarized. Both of the beams can be generated from a laser source with high spatial and temporal coherence such that the beams interfere strongly to form an upright pattern of overlapping beams. Within the recording medium, the pattern is the expression,
θ _t =(θ _o +θ _r )/2(10)
With a fringe inclination angle θ _t satisfying
where θ _t represents the fringe inclination angle of the recording medium during recording, θ _o represents the object angle of the recording medium during recording, and θ _r represents the reference angle of the recording medium during recording.

The fringe spacing (or fringe period) d on the surface of the recording medium is
d=λ _record /(n sinθ _record ) (11)
It can be expressed as,
where λ _record represents the recording wavelength (in vacuum), n represents the refractive index of the medium surrounding the grating (e.g. air with n = 1.0), and θ _record is the inter-beam angle during recording. is the same as |θ _o −θ _r |, where θ _o represents the object incidence angle at the surface of the recording medium during recording, and θ _r represents the reference incidence angle at the surface of the recording medium during recording. . In some cases, the fringe spacing d has a size similar to the wavelength of the recording light, eg, 0.5 μm. Therefore, the fringe pattern may have a frequency f=1/d, for example about 2,000 fringes/mm. The thickness D of the recording medium can be more than an order of magnitude larger than the wavelength of the recording light. In some examples, the thickness D of the recording medium is about 30 times the wavelength, eg, about 16.0+/-2.0 μm. The carrier film may have a greater thickness than the recording medium, for example 60 μm. The substrate can have a thickness several orders of magnitude greater than the recording medium, for example about 1.0 mm.

After the fringe pattern or grating is recorded on the recording medium, the fringe pattern is exposed to, for example, deep blue light or ultraviolet (UV) light, which can freeze the fringe in place and also enhance the refractive index difference of the fringe. ) Can be fixed to a recording medium by exposure to light, as an example of a photopolymer. The recording medium can be reduced during fixation. The recording medium can be selected to have a low shrinkage rate during fixation, for example less than 2%, or can compensate for such shrinkage.

As each beam passes through an interface between materials of different refractive index, some portion of the beam is reflected according to Fresnel's law, yielding a fraction of the power reflected at each transition. Reflection is polarization dependent. For light with a smaller angle of incidence, for example 30°, the Fresnel reflection can be weaker. For light with a larger angle of incidence (eg, 80°) and with s-polarization, the Fresnel reflection can be stronger. When the angle of incidence reaches or exceeds the critical angle, total internal reflection (TIR) occurs, ie, the reflectance is 100%. For example, from the transition from glass (n=1.5) to air (n=1.0), the critical angle is about 41.8°. Since the refractive index is polarization-dependent and weakly wavelength-dependent, the reflected power at large angles of incidence can be weakly wavelength-dependent and strongly polarization-dependent.

FIG. 7B illustrates an example of diffracting a reproduction reference beam by the grating of FIG. 7A. In the case of transmission holography, the substrate is transparent during reproduction. The substrate can also be an optically clear plastic such as TAC or some other low birefringence plastic. If the recorded grating in the recording medium is thin compared to the wavelength of the reproduction reference beam, e.g. if the thickness of the recording medium is less than an order of magnitude greater than the reproduction wavelength, the diffraction angle of the grating will be
m λ _replay = n d (sin θ _in - sin θ _out ) (12)
It can be described by a lattice equation as
where m represents the diffraction order (integer), n represents the refractive index of the medium surrounding the grating, d represents the fringe spacing on the surface of the recording medium, and θ _in represents the distance from the surrounding medium to the grating. θ _out represents the output angle of the mth order from the grating to the surrounding medium, and λ _replay represents the replay wavelength in vacuum.

If the recorded grating is relatively thick, for example if the thickness of the recording medium is more than an order of magnitude (eg, 30 times) larger than the reproduction wavelength, the grating can be referred to as a volume grating or a Bragg grating. For volume gratings, Bragg selectivity can strongly enhance the diffraction efficiency at the Bragg angle. The Bragg angle can be determined based on numerical methods, such as exact coupled wave solutions, and/or experimentation and iteration. Off-Bragg angles can substantially reduce diffraction efficiency.

The Bragg condition can be satisfied if the angle of incidence on the fringe plane is equal to the angle of diffraction from the fringe plane in the medium containing the fringe plane. Then, the lattice equation (12) is the Bragg equation,
m λ _replay =2 n _replay Λ _replay sin(θ _m −θ _t ) (13)
It can be,
where m represents the diffraction order (or Bragg order), n _replay represents the refractive index in the medium, Λ _replay represents the fringe spacing in the recording medium, and θ _m represents the m represents the Bragg angle, θ _t represents the fringe slope in the recording medium, and Λ _replay can be the same as d cos θ _t .

The Bragg condition can be automatically satisfied for volume gratings that are recorded and reproduced at the same angle and wavelength (assuming no shrinkage during processing). For example, as illustrated in FIG. 7B, a volume grating is recorded and played back at the same wavelength (e.g., green) and reference angle (e.g., θ _r ), and the grating is of first order at the angle of the recording object beam. The reproduction beam can be diffracted. A small portion of the incident light beam may pass through the grating as an unpolarized or undiffracted zero-order light beam. When the zero order light beam reaches a display such as a reflective LCOS device, the light beam can cause undesirable effects, such as ghost images.

When the reproduction reference angle is not changed but the reproduction reference wavelength is changed, the diffraction efficiency η of the Bragg grating in the recording medium is
η∝2D _replay sinθ _Bragg ² δλ cosθ _{tilt. replay} /(λ _Bragg ² cosθ _Bragg ) (14)
It can be expressed as,
where η represents the diffraction efficiency, D _replay represents the thickness (after shrinkage) of the recording medium during playback, and θ _Bragg is the playback reference angle (after shrinkage) at Bragg of the intended playback wavelength λ _Bragg . ), δλ represents the error in the reproduction wavelength, that is, δλ=|λreplay−λBragg|, and θ _{tilt. replay} represents the fringe slope (after shrinkage) of the recording medium during playback. All λ's are values in vacuum.

FIG. 7C illustrates an example of recording different colored gratings on a recording medium using different colored lights. As illustrated, three fringe patterns (or gratings) can be recorded on a single recording medium, eg, sequentially or simultaneously. The fringe pattern corresponds to the reproduction color (eg red, green, or blue) and can be recorded at different wavelengths. The recording reference beam and the recording object beam have the same polarization state. Each beam can be s-polarized. The recording reference beam of each color can be incident on a single recording medium at the same reference beam angle θ _r (eg, +30°). The recording object beams of each color may be incident on a single recording medium at the same object beam angle θ _o (eg -20°).

Since θ _t is independent of wavelength, the fringe plane slope θ _t of each grating during recording may be the same, for example θ _t =(θ _o +θ _r )/2. The fringe spacing d perpendicular to the fringe plane during recording can be different for each grating since d depends on the wavelength. In some examples, as illustrated in FIG. 7C, the fringe spacing corresponds to exemplary wavelengths of 640nm:520nm:460nm.
This is the percentage of

FIG. 7D illustrates an example of recording gratings of different colors on a recording medium using light of the same color. Similar to FIG. 7C, three fringe patterns are recorded on a single photopolymer, one fringe pattern for each reproduced color. Unlike FIG. 7C, the three fringe patterns in FIG. 7D can be recorded using the same wavelength, eg, green light. To achieve this, the recording object beam for each reproduction color can be incident on a single recording medium at different object beam angles, and the recording reference beam for each reproduction color can be incident on a single recording medium at different reference beam angles. can be incident on the recording photopolymer. The fringe slope and fringe spacing of FIG. 7D for a reproduced color can be matched with the fringe slope and fringe spacing of the same reproduced color in FIG. 7C.

FIG. 7E illustrates an example of diffracting different colored reproduction reference beams by different colored gratings. The grid can be recorded as illustrated in FIG. 7C or 7D. Similar to Figure 7B, for the reproduction color, if the recording wavelength is the same as the reproduction wavelength and the reproduction reference angle is the first Bragg angle of the grating of the reproduction color, then the grating has a diffraction angle that is the same as the recording object angle. The first-order reproduction reference beam is diffracted at the reproduction reference angle, and the zero-order reproduction reference beam is transmitted at the reproduction reference angle. Due to Bragg selectivity, the power of the first order reproduction reference beam can be substantially greater than the power of the zero order reproduction reference beam. The three reproduction reference beams may have the same angle of incidence, for example 30°, and the first order diffracted beams may have the same angle of diffraction, for example 20°.

The reproduction reference angles of each color are neither equal to each other nor can they be equal to the angle of the color used during recording. For example, for green, the grating is recorded at 532 nm using a high power, high coherence green laser, such as a frequency-doubled diode-pumped YaG laser, and then regenerated at 520 ± 10 nm using a green laser diode. be able to. In some cases, a green laser with a wavelength of 532 nm can also be used to record the fringe pattern required for playback using an inexpensive red laser diode of 640±10 nm. For blue, a HeCd laser can be used to record the grating at 442 nm and a 460±2 nm blue laser diode can be used for reproduction.

FIG. 7F illustrates an example of crosstalk between diffracted beams of different colors. Despite Bragg selectivity, each color can also slightly diffract the gratings recorded for each other, which can cause crosstalk between these colors. Compared to FIG. 7E, which provides only the first order diffraction for the corresponding color, FIG. 7F provides the first order diffraction for each color from each grating.

For example, as illustrated in FIG. 7F, a red grid, a green grid, and a blue grid are recorded for red, green, and blue, respectively. When red light is incident on the red grating at the same reference angle of 30°, the diffraction angle of the first-order red light is 20°, but when red light is incident on the green grating at the same reference angle of 30°, the diffraction angle of the first-order red light is 20°. The diffraction angle of the red light is 32°, and when the red light is incident on the blue grating at the same reference angle of 30°, the diffraction angle of the first-order red light is 42°. Therefore, the diffracted light can exist at unintended angles, causing color crosstalk. Similarly, if green light is incident on a green grating at a reference angle of 30°, the diffraction angle of the first order green light is 20°, but if green light is incident on a red grating at the same reference angle of 30°. , the diffraction angle of the first-order green light is 11°, and when the green light is incident on the blue grating at a reference angle of 30°, the diffraction angle of the first-order green light is 27°. Therefore, the diffracted light can exist at unintended angles, causing color crosstalk. Similarly, when blue light is incident on a blue grating at a reference angle of 30°, the diffraction angle of the first-order blue light is 20°, but when blue light is incident on a red grating at the same reference angle of 30°. , the diffraction angle of the first-order blue light is 6°, and when the blue light is incident on the green grating at the same reference angle of 30°, the diffraction angle of the first-order blue light is 14°. Therefore, the diffracted light can exist at unintended angles, causing color crosstalk. Therefore, when a single color light, for example green light, is incident on the three gratings of the recording medium, the three gratings will diffract the single color light into a first diffraction with a diffraction angle of 20°. a second diffracted green light with a diffraction angle of 27°, and a third diffracted green light with a diffraction angle of 11°. The two unintended angles of each color of light being diffracted can produce undesirable effects.

In some cases, rather than recording three different gratings of three different colors on a single recording layer, three different gratings are instead recorded on three separate recording layers that are stacked together. Can be memorized. Similar to FIG. 7F, if three colors of light are incident on any one of the gratings at the same angle of incidence, color crosstalk may occur. Implementations of the present disclosure provide methods and devices for suppressing color crosstalk within multiple grating stacks, as illustrated in further detail in FIGS. 9A-12C.

FIG. 8 illustrates an example of recording a holographic grating with a large reference angle on a recording medium. Using a large playback reference beam angle can enable thin playback systems. Also, the reproduction output beam, ie, the diffraction angle of the first order, may be perpendicular to the display. Therefore, the recorded object beam may be close to normal incidence, as illustrated in FIG.

For Bragg diffraction, the Fresnel reflections of both p- and s-polarized light are low at each fringe plane, but at an angle of incidence of 45°, s-polarized light can be reflected orders of magnitude more strongly than p-polarized light. Therefore, if the angle of incidence of the reproduction reference to the fringe in the recording medium is close to 45°, the Bragg resonance from the fringe can be very polarization sensitive, strongly favoring s-polarization. The recording object beam may be at approximately normal incidence on the recording medium, just as the reconstructed object beam or diffracted reproduction beam may be at approximately normal incidence on the display. Since the fringe tilt in the recording medium is the average value of the recording object in the medium and the reference angle, the recording Recording reference angles approaching 90° within the media can be used. The beam-to-beam angle between the recorded object beam and the recorded reference beam can be close to 90°. For example, the inter-beam angle is 84°, the fringe slope of the fringe plane in the recording beam is 42°, and the angle of incidence of the reproduction reference beam with respect to the fringe plane is 48°, as illustrated in FIG. °, which corresponds to a polarization sensitivity of approximately 90:1.

In some cases, in order to make the reproduction output (or first order) diffraction angle 0°, the recording object beam may not be identical to 0°, but close to 0°, and this is due to the recording during its processing. This can be achieved by taking into account a combination of shrinkage of the medium and a slight wavelength difference between the recording and reproduction wavelengths. For example, the recording object angle may be in the range -10° to 10°, such as -7° to 7°, or in the range 5° to 7°. In some examples, the recording object angle is 0°. In some examples, the recording object angle is 6°.

In some implementations, in order to achieve a sufficiently large inter-beam angle during recording, e.g. close to 90°, a prism is applied such that each recording beam enters the prism through a prism face, and the prism The angle of incidence on the prism is close to the normal to that face of the prism, so that both refraction and Fresnel losses are negligible. The prism can be index matched to the cover film or substrate of the recording medium at the interface such that refractive index mismatch is negligible at the interface, and refractive and Fresnel losses can also be ignored at the interface.

Exemplary Optical Diffractive Devices FIGS. 9A-12C illustrate implementations of exemplary optical diffractive devices. Any one of the devices can correspond, for example, to optical diffraction device 598 of FIG. 5H or 598C of FIG. 5K. Optical diffraction devices individually diffract light in multiple colors to suppress (e.g., reduce or eliminate) color crosstalk between diffracted light and/or to suppress zero-order undiffracted light. It is configured to allow 9A-10B illustrate exemplary optical diffraction devices that include color-selective polarizers. Color-selective polarizers can selectively change the polarization of selected colors, so light of a single color can have s-polarization to achieve high diffraction efficiency in the first order However, other colors of light are p-polarized and therefore have lower diffraction efficiency in the first order. 11-12C illustrate exemplary optical diffractive devices that include reflective layers. The reflective layer can selectively completely reflect light of a single zero-order color while transmitting light of other colors.

Optical Diffraction Device with Color-Selective Polarizer FIG. 9A illustrates an exemplary optical diffraction device 900 that includes a two-color holographic grating and a corresponding color-selective polarizer, and FIG. An example 950 of diffracting two colors of light by an optical diffraction device 900 is illustrated. For purposes of illustration, device 900 is configured for green light and blue light.

Optical diffraction device 900 includes a first optical diffraction component 910 having a first grating (B grating) 912 for blue light and a second grating (G grating) 922 for green light. a second optical diffractive component 920 having a second optical diffractive component 920 . Each of the diffraction gratings may be between a carrier film, e.g. a TAC film, and a substrate, e.g. a glass substrate. The carrier film can be after the grating and the substrate can be in front of the grating along the Z direction, or vice versa. As illustrated in FIG. 9A, a first optical diffractive component 910 includes a substrate 914 and a carrier film 916 on either side of a B grating 912, and a second optical diffractive component 920 includes a substrate 914 and a carrier film 916 on both sides of a G grating 922. includes a substrate 924 and a carrier film 926. Optical diffraction device 900 can include a field grating substrate 902 upon which a first optical diffractive component 910 and a second optical diffractive component 920 are stacked. An anti-reflection (AR) coating 901 can be attached to or applied to the surface of field grating substrate 902 to reduce reflections at that surface.

Optical diffraction device 900 may also include one or more layers of an optically clear index-matching adhesive (OCA), a UV-cured or heat-cured optical adhesive, an optical contact, or an index-matching fluid to separate adjacent layers or structures. elements, such as field grating substrate 902 and BY filter 904, BY filter 904 and first diffractive component 910 (or substrate 914), first diffractive component 910 (or carrier film 916) and GM filter 906, and/or Alternatively, GM filter 906 and second diffractive component 920 (or substrate 924) can be attached or deposited together. The order of the carrier film 914 or 924, the substrate 916 or 926, and the OCA layer is determined based on their refractive index at the wavelength of the reproduction light to reduce the refractive index mismatch at the interface and, therefore, to reduce the refractive index mismatch at the interface. Fresnel reflection can be reduced.

Each of the first diffraction grating and the second diffraction grating is independently a holographic grating (e.g., a volume grating or a Bragg grating) recorded and fixed (e.g., hardened) on a recording medium, e.g. a photosensitive polymer. could be. The thickness of the recording medium can be more than an order of magnitude greater than the recording wavelength, for example about 30 times. Similar to what is illustrated in FIG. 7A or FIG. 8, the recording reference light beam incident on the recording medium at the recording reference angle and the recording object light beam incident on the recording object angle interfere with the recording medium, A diffraction grating can be formed. The reproduction reference light beam can then be diffracted in the first and zero orders by the recorded grating, similar to that illustrated in FIG. 7B. The recording light beam and the reproduction light beam can have the same s-polarization state. The reproduction wavelength of the reproduction light beam may be substantially the same as the recording wavelength of the recording light beam.

In some examples, the playback incidence angle can be substantially the same as the recording reference angle (or Bragg angle) and can satisfy the Bragg condition. The first order light (or primary light) is diffracted at a diffraction angle substantially close to the recording object angle, and the zero order light (or zero order light) is transmitted without being diffracted at the playback incidence angle. Due to Bragg selectivity, the power of the first order light can be substantially higher than the power of the zero order light. The power of the zero-order light (eg, afterglow or depletion light) depends on the diffraction efficiency of the diffraction grating. The higher the diffraction efficiency, the lower the power of the zero-order light. In some examples, the recording reference angle, the recording object angle, the reproduction incidence angle, the recording wavelength, and the reproduction wavelength are such that the reproduction output angle (or the angle diffracted in the first order) is substantially close to 0° or the grating It can be configured to be perpendicular to. The diffraction angle may be in the range -10° to 10°, such as -7° to 7°, 0° to 10°, or 5° to 7°. In a particular example, the diffraction angle is 6°.

In addition, due to polarization sensitivity, the diffraction efficiency of s-polarized light of the first color (for example, blue) that is incident at the reproduction reference angle and diffracted in the first order at the diffraction angle is The diffraction efficiency can be substantially higher than that of p-polarized light of the same color diffracted in the first order. As illustrated in FIG. 7F, the second color light (e.g., green) that is incident at the same reproduction incidence angle as the first color light has a diffraction angle that is different from the first color light. It is diffracted at different angles. Therefore, for both Bragg sensitivity and polarization sensitivity, the diffraction efficiency of the first color incident in the s-polarization state at the reproduction incidence angle is greater than the diffraction efficiency of the first color incident in the p-polarization state at the same reproduction incidence angle or at a different reproduction incidence angle. The diffraction efficiency of two colors of light can be substantially higher.

Optical diffraction device 900 can be configured to suppress crosstalk between the blue and green diffracted light beams. For example, if B grating 912 is positioned in front of G grating 922 in device 900 along the Z direction, light will be incident on B grating 912 before being incident on G grating 922. Optical diffraction device 900 has blue light incident on B grating 912 in an s polarization state, green light incident on B grating 912 in a p polarization state, and green light entering G grating 922 in an s polarization state. It can be configured to be incident on. In some cases, optical diffraction device 900 can also be configured such that the remaining blue light enters G grating 922 in a p-polarization state.

In some implementations, as shown in FIGS. 9A and 9B, the optical diffractive device 900 is arranged between a first diffractive grating 912 and a second diffractive grating 922 (or between a first diffractive component 910 and a first A color selective polarizer 906 (also known as a color selective retarder or filter) can be included between the two diffractive components 920). Color-selective polarizer 906 includes a GM filter configured to rotate the polarization state of green light by 90 degrees, for example from a p-polarization state to an s-polarization state, without rotating the polarization state of blue light. can be included.

In some implementations, as shown in FIGS. 9A and 9B, the optical diffraction device 900 includes another color selection in front of the first grating 912 and the second grating 922 along the Z direction. A polarizer 904 can be included. Color-selective polarizer 904 includes a BY filter configured to rotate the polarization state of blue light by 90 degrees from a p-polarization state to an s-polarization state without rotating the polarization state of green light. be able to.

As shown in FIGS. 9A and 9B, both blue light 952 and green light 954 can be incident in the p-polarized state into optical diffraction device 900, simultaneously or sequentially. The two colors of light can have the same angle of incidence θ°. When blue light 952 and green light 954 are initially incident on the BY filter 904, the color-selective polarizer 904 causes the blue light to enter the B grating 912 in the s-polarized state and the green light to be in the p-polarized state. The p-polarization state of the blue light is rotated to the s-polarization state without rotating the polarization state of the green light so that the blue light enters the B grating 912 in the same state. B grating 912 diffracts blue light in the s-polarization state into first-order blue light 952' at a certain diffraction angle with a first diffraction efficiency, and diffracts zero-order blue light 952'' at an incident angle. Transmit. Due to polarization sensitivity and Bragg sensitivity, B grating 912 diffracts green light 954 in the p-diffraction state with a diffraction efficiency that is substantially less than the first diffraction efficiency, and Most of the light passes through the B grating 912. Color selective polarizer 906 causes G grating 922 to diffract first order green light 954' at a diffraction angle and transmit zero order green light 954' at an angle of incidence with a second diffraction efficiency. , the p-polarization state of green light is rotated to the s-polarization state without rotating the s-polarization state of blue light. Thus, the diffracted blue light 952' and the green light 954' are in the same s polarization state and at the same diffraction angle, e.g. It exits the optical diffraction device 900 substantially close to 0° or perpendicular to the device 900.

As shown in FIG. 5H, optical diffraction device 900 can be positioned along the Z direction in front of a cover glass 930 of a display, eg, display 594 of FIG. 5H. As discussed above in FIG. 5H, the optical diffraction device 900 can be attached to the cover glass 930 with an OCA layer or index matching oil, or separated by a gap, such as an air gap. The diffracted blue light 952' and green light 954' may be incident on the display with the same s-polarization state and the same angle of incidence (eg, substantially normal incidence). The display can diffract blue light 952' and green light 954' back into and through optical diffraction device 900. The blue and green light diffracted from the display cannot be further significantly diffracted by the optical diffraction device 950 because they are incident on the gratings 912 and 922 at far off-Bragg angles.

The display 594 can be illuminated by polarizing the light in the direction of the display's alignment layer or in a direction perpendicular to the display's alignment layer. Since the display can be rotated in its own plane between horizontal and vertical orientation, which polarization is needed depends on which orientation the display is in. In some implementations, the display can be illuminated with p-polarized light. The blue light and green light diffracted from the optical diffraction device 900 may be incident on the display in the same p-polarization state. Optical diffraction device 900 may include an additional color-selective polarizer after G grating 922 to rotate the s-polarization state of each of blue light 952' and green light 954' to a p-polarization state.

In some implementations, the blue light is incident on the optical diffraction device 900 in the s-polarization state, the green light is incident on the p-polarization state, and the optical diffraction device 900 is configured to change the polarization state of the blue light. A BY filter 904 may not be included in front of the B grating 912 for rotation.

In some implementations, zero-order undiffracted (or transmitted) blue light and/or zero-order undiffracted (or transmitted) green light, as discussed in more detail in FIGS. 11-12C. The light can be completely internally reflected by one or more reflective layers disposed within the optical diffraction device 900.

FIG. 10A illustrates an example optical diffraction device 1000 that includes a three-color holographic grating and a corresponding color-selective polarizer for individually diffracting three colors of light. FIG. 10B illustrates an example of diffracting three colors of light by the optical device of FIG. 10A. ．． Compared to FIGS. 9A and 9B, optical diffractive device 1000 includes additional diffractive components for additional colors and different color-selective polarizers for three colors. For purposes of illustration, device 1000 is configured for blue light, red light, and green light.

As illustrated in FIG. 10A, the optical diffraction device 1000 can be placed in front of the cover glass 1050 of a display, such as display 594 of FIG. 5H, along the Z direction. The optical diffractive device 1000 includes a first diffractive component 1010, a second diffractive component 1020, and a third diffractive component 1030, which can be stacked sequentially on a field grating substrate 1002 along the Z direction. include. The AR film 1001 can be painted or coated on the front surface of the field grating substrate 1002 to reduce light reflection. Each of the first diffractive component 1010, the second diffractive component 1020, and the third diffractive component 1030 includes a respective substrate 1014, 1024, 1034, a respective diffractive grating 1012, 1022, 1032, and a respective diffractive grating 1012, 1022, 1032. A carrier film 1016, 1026, 1036 can be included. A respective grating 1012, 1022, 1032 is between a respective substrate 1014, 1024, 1034 and a respective carrier film 1016, 1026, 1036. In some cases, the respective substrates 1014, 1024, 1034 are in front of the respective carrier films 1016, 1026, 1036 along the Z direction. In some cases, the respective carrier film 1016, 1026, 1036 is in front of the respective substrate 1014, 1024, 1034 along the Z direction.

Each of the first diffraction grating 1012, the second diffraction grating 1022, and the third diffraction grating 1032 receives monochromatic light in the s-polarized state incident at a certain angle of incidence, and the diffraction grating receives monochromatic light in the s-polarization state that is incident at a certain angle of incidence. It can be configured to diffract at a diffraction angle that is substantially, e.g., more than one, two or more, or three or more orders of magnitude higher than the diffraction efficiency at which light of another color is diffracted in the incident p-polarized state. can. Each of first grating 1012, second grating 1022, and third grating 1032 may be a holographic grating, such as a volume grating or a Bragg grating. Each of the first diffraction grating 1012, the second diffraction grating 1022, and the third diffraction grating 1032 can be independently recorded and fixed on a recording medium, such as a photosensitive polymer or a photopolymer.

Optical diffraction device 1000 can include multiple color-selective polarizers for three colors of light. In some implementations, the BY filter 1004 is between the field grating substrate 1002 and the first grating 1012 of the first diffractive component 1010, and the BY filter 1004 is located between the field grating substrate 1002 and the first diffraction grating 1012 of the first diffraction component 1010 to determine the polarization state of each of the red light and the green light. It is configured to rotate the polarization state of blue light without rotation. The MG filter 1006 is located between the first diffraction grating 1012 and the second diffraction grating 1022 (or between the first diffraction component 1010 and the second diffraction component 1020), and filters green light. It is configured to rotate the polarization states of each of blue light and red light without rotating the polarization state. A YB filter 1008 is located between the second diffraction grating 1022 and the third diffraction grating 1032 (or between the second diffraction component 1020 and the third diffraction component 1030) and polarizes the blue light. The polarization state of each of red light and green light is configured to be rotated without rotation of the state. The MG filter 1040 is after the third diffraction grating 1032 (or third diffraction component 1030) and changes the polarization state of each of the red and blue lights without rotating the polarization state of the green light. It is configured to rotate.

In some implementations, the color selective polarizer is comprised of two or more sub-polarizers. The sub-polarizers can be arranged in any desired order. For example, the YB filter 1008 can be configured with an RC filter 1008-1 and a GM filter 1008-2. RC filter 1008-1 can be placed before GM filter 1008-2, or vice versa. The RC filter 1008-1 is configured to rotate the polarization state of red light without rotating the polarization state of each of green light and blue light, and the GM filter 1008-2 is configured to rotate the polarization state of red light. The polarization state of the green light is rotated without rotating the polarization states of the green light and the blue light.

Adjacent layers or components within optical diffraction device 1000 may be attached together using an interlayer of one or more of OCA, UV-cured or thermoset optical adhesives, optical contacts, or index-matching fluids. can. As discussed in FIG. 5H, the optical diffractive device 1000 can be attached to the display cover glass 1050 through an interlayer or separated by a gap, eg, an air gap.

Optical diffraction device 1000 emits three colors of light (red, green, and blue) at the same polarization state (e.g., s or p) and at the same diffraction angle (e.g., substantially normal incidence) toward a display. It is configured to cause diffraction. The three colors of light may enter the optical diffraction device 1000 at the same angle of incidence θ°, which is, for example, substantially the same as the Bragg angle. In some cases, the three colors of light can be incident at different angles to match the Bragg angle of each color's grating. The three colors of light can be in a beam large enough to illuminate the entire area of the grating. Three colors of light can enter the optical diffraction device 1000 with the same polarization state (eg, s or p). In some cases, light of one color is incident from the opposite side (eg, at −θ°) or from the Y direction. Each color grating can be rotated to match the direction of the corresponding color reproduction reference light. The corresponding color-selective polarizer may be independent of the rotation of the color grating.

FIG. 10B illustrates an example 1060 of diffracting three colors of light (blue, red, green) by the optical diffraction device 1000 of FIG. 10A. The three colors of light enter the optical diffraction device 1000 at the same angle of incidence θ° and the same p-polarization state.

As shown in FIG. 10B, the BY filter 1004 rotates the p-polarization state of blue light to the s-polarization state without rotating the p-polarization state of each of red and green light. The B grating 1012 diffracts blue light in the s-polarization state to the first order at the diffraction angle and to the zero order at the incident angle. Green light and red light incident in the p-polarized state at the incident angle are transmitted through the B grating 1012.

The MG filter 1006 rotates the s-polarization state of blue light to the p-polarization state and the p-polarization state of red light to the s-polarization state without rotating the p-polarization state of green light. The R grating 1022 diffracts red light in the s-polarization state to the first order at the diffraction angle and to the zero order at the incident angle. The remaining zero-order blue light and the green light incident in the p-polarization state at the angle of incidence are transmitted through the R grating 1022.

The RC filter 1008-1 in the YB filter 1008 rotates the s-polarization state of the red light to the p-polarization state without rotating the p-polarization state of each of the green light and the blue light. The GM filter 1008-2 of the YB filter 1008 rotates the p-polarization state of the green light to the s-polarization state without rotating the p-polarization of each of the red light and the blue light. The remaining zero-order blue light, remaining zero-order red light, and green light pass through the RC filter 1008-1 and the GM filter 1008-2.

The G grating 1032 diffracts green light in the s-polarization state to the first order at the diffraction angle and to the zero order at the angle of incidence. The remaining blue light and the remaining red light, which is incident in the p-polarization state at the angle of incidence, is transmitted through the G grating 1032.

The MG filter 1040 rotates the p-polarization state of each of the red light and blue light to the s-polarization state without rotating the s-polarization state of the green light. Diffracted blue, red, and green light in the s-polarization state at the same diffraction angle propagates from the optical diffraction device 1000. The remaining blue light, the remaining red light, and the zero-order remaining green light are also in the s-polarization state and are transmitted through the MG filter 1040 at the angle of incidence.

In some implementations, optical diffractive device 1000 can have a larger size than the display. The remaining zero-order blue, red, and green light can propagate out of the device 1000 and into the air at large angles. In some implementations, as discussed in more detail below in FIGS. 11-12C, the optical diffraction device 1000 includes a filter between or after the diffraction grating for total internal reflection of zero-order, corresponding color light. One or more reflective layers can be included.

Exemplary Optical Diffractive Device with Reflective Layer FIGS. 11-12C illustrate an exemplary optical diffractive device that includes a reflective layer. The reflective layer can selectively completely reflect light of a single zero-order color while transmitting light of other colors. Each optical diffraction device includes multiple gratings, each for a different color of light. Each color of light can be incident on the corresponding grating at a different reproduction reference angle, and thus the zero-order, each color of light that is not diffracted (or transmitted) by the grating will be transmitted to subsequent gratings (present following a grating that diffracts light of the first order color at the same diffraction angle (e.g., substantially perpendicular), prior to total internal reflection (TIR) from the interface. Other colors of light can be transmitted through the grating at corresponding reproduction reference angles.

FIG. 11 illustrates an example optical diffraction device 1100 that includes a two-color diffraction grating and a corresponding reflective layer for individually diffracting two colors of light. For purposes of illustration, device 1100 is configured for green light and blue light.

Optical diffraction device 1100 includes a first diffraction component 1110 having a first diffraction grating 1112 for blue color and a second diffraction component 1120 having a second diffraction grating 1122 for green color. . Each of the first grating 1112 and the second grating 1122 may be a holographic grating, such as a Bragg grating or a volume grating. Each of the first diffraction grating 1112 and the second diffraction grating 1122 can be independently recorded and fixed on a recording medium, for example a photosensitive material such as a photopolymer.

The first diffractive component 1110 and the second diffractive component 1120 can be stacked together on the field grating substrate 1102 along a direction, eg, the Z direction. Field grating substrate 1102 may be an optically transparent substrate, such as a glass substrate. Optical diffraction device 1100 may be in front of a display such as an LCOS, for example display 594 in FIG. 5H. For example, the optical diffraction device 1100 can be placed on the cover glass 1130 of the display through an interlayer or separated by a gap, eg, an air gap.

Similar to first diffractive component 910 and second diffractive component 920 of FIGS. 9A and 9B, each of first diffractive component 1110 and second diffractive component 1120 includes a respective diffractive grating 1112, 1120. may include respective substrates 1114, 1124 and respective carrier films 1116, 1126 on either side. A respective grating 1112, 1122 is between a respective substrate 1114, 1124 and a respective carrier film 1116, 1126. The respective substrates 1114, 1124 and the respective carrier films 1116, 1126 can be arranged in an order to reduce refractive index mismatch and therefore unwanted Fresnel reflections. Each substrate 1114, 1124 can be a glass substrate that can have a refractive index the same as or close to that of field grating substrate 1102. Each carrier film 1116, 1126 can be a TAC film. The TAC film can have a lower refractive index than the photopolymer used to record the gratings 1112 and 1122. In some examples, a respective substrate 1114, 1124 is placed in front of a carrier film 1116, 1126.

Adjacent layers or components within the optical diffraction device 1100 may be attached together using interlayers of one or more of OCA, UV-cured or heat-cured optical adhesives, optical contacts, or index-matching fluids. can. For example, a first diffractive component 1110 (eg, substrate 1114) can be coupled to field grating substrate 1102 through an intermediate layer 1101, eg, an OCA layer. The first diffractive component 1110 and the second diffractive component 1120, eg, carrier film 1116 and substrate 1124, can be attached together through another intermediate layer 1103, eg, an OCA layer. Optical diffraction device 1100 (eg, carrier film 1126) can be attached to a display cover glass 1130 through an interlayer 1105, eg, an OCA layer.

As shown in FIG. 11, each of the first diffraction grating 1112 and the second diffraction grating 1122 converts the light of the corresponding color incident at each incident angle into primary order at each diffraction angle. It is configured to cause zero-order diffraction at a corner and transmit light of different colors at different angles of incidence, for example due to Bragg selectivity. Therefore, there can be no crosstalk between the different colors of light that are individually diffracted by the corresponding diffraction gratings. Each color of light can be polarized. The polarization states of the first order diffracted light of different colors may be the same, for example s or p. The respective diffraction angles for light of different colors may be the same, eg substantially perpendicular.

Optical diffraction device 1100 can include a first reflective layer (or blocking layer) between first grating 1112 and second grating 1122. The first grating 1112 diffracts blue light incident at a first angle of incidence θ _b , e.g., 78.4°, into the first order at a certain diffraction angle, e.g., 0°, and into the zero order at the first angle of incidence. It is configured to cause diffraction to occur. The refractive index of the first reflective layer, e.g., the first reflective layer, completely reflects the blue light diffracted at the first angle of incidence, but at the second angle of incidence, θ _g , e.g., 76.5 It is configured to transmit green light incident at . For example, the refractive index of the first reflective layer is lower than the refractive index of the first reflective layer, eg, the layer immediately preceding the first grating 1112. The first reflective layer may be a suitable layer between the first grating 1112 and the second grating 1122. In some examples, the first reflective layer is a carrier film 1116, as shown in FIG.

Similarly, optical diffraction device 1100 can include a second reflective layer after second grating 1122 and before display cover glass 1130. The second grating 1112 diffracts green light incident at a second angle of incidence θ _g , e.g. 76.5°, to the first order at a certain diffraction angle, e.g. 0°, and to the zeroth order at a second angle of incidence. It is configured as follows. The second reflective layer, e.g. the refractive index of the second reflective layer, is configured to completely reflect the green light diffracted at the second angle of incidence. A second reflective layer may be a suitable layer between second grating 1122 and cover glass 1130. In some examples, the second reflective layer is an intermediate layer 1105, as shown in FIG.

The blue light and green light completely reflected by the corresponding reflective layers are reflected back to the optical diffractive device 1100 against the side of the optical diffractive device 1100. As illustrated in FIG. 11, the side surface is coated with a light absorber 1104, e.g. a black coating, so that the fully reflected blue light and green light are diffracted in the zeroth order by the corresponding gratings. can be absorbed.

The field grating substrate 1102 may be thick enough to allow different colored reproduction reference light beams to enter its edges of the field grating substrate 1102. Field grating substrate 1102 can also be configured to completely contain the reproduction reference light beam such that a viewer or observer cannot insert a finger or other object into the reproduction reference light beam. Therefore, the viewer cannot obstruct the reproduction reference light beam, which improves laser safety as the viewer cannot put his eyes (or reflective or focusing elements) into the full power reproduction reference light beam. be able to. Optical diffraction device 1100 with field grating substrate 1102 may be significantly more compact than if the reproduction reference light beam is incident from the air onto the front surface of optical diffraction device 1100.

Since blue and green light are incident at relatively large reproduction reference angles (or angles of incidence), e.g. greater than 70°, Fresnel reflections are significant from layer interfaces (for both P and S polarization). , and can increase rapidly with increasing playback reference angle. Because the optical diffraction device 1100 includes several interfaces between materials of different refractive index, Fresnel reflection losses from each such interface increase substantially attenuating the reproduced output light, and each diffraction grating , particularly in the grating closest to the display, e.g. G grating 1122, can cause a substantially reduced reproduction optical power. In some instances, the reproduction reference angle (or angle of incidence) for a particular color of light is just large enough to ensure TIR, but not so large that Fresnel losses can be reduced. You can choose not to.

Figures 13A-13C show the diffracted reproduction reference beam power (solid lines) and reflections with different angles of incidence for blue light (Figure 13A), green light (Figure 13B), and red light (Figure 13C). The relationship with the reproduced reference beam power that is interrupted or interrupted (dashed line) is illustrated. The diffracted reproduction reference beam power may be an illumination beam onto a display, eg, a cover glass of a display 594 of FIG. 5H, adjacent to an optical diffraction device, eg, optical diffraction device 598 of FIG. 5H.

As illustrated in FIG. 13A, for blue light, plot 1302 shows that as the reproduction reference beam angle (e.g., angle of incidence in the glass) increases, the diffracted reproduction reference beam power (or The plot 1304 shows the reflected reproduction reference beam power from the corresponding reflective layer as the reproduction reference beam angle increases. As illustrated in FIG. 13B, for green light, plot 1312 shows that as the reproduction reference beam angle (e.g., the angle of incidence in the glass) increases, the diffracted reproduction reference beam power (or The plot 1314 shows the reflected reproduction reference beam power from the corresponding reflective layer as the reproduction reference beam angle increases. As illustrated in FIG. 13C, for red light, plot 1322 shows that as the reproduction reference beam angle (e.g., angle of incidence in the glass) increases, the diffracted reproduction reference beam power (or The plot 1324 shows the reflected reproduction reference beam power from the corresponding reflective layer as the reproduction reference beam angle increases.

The reproduction reference angles of different colors of light can be chosen to be large enough for each color of light so that the corresponding reflective layer can fully reflect the color of light with 100% reflection; , the reproduction reference angle may be small enough such that Fresnel losses do not substantially eliminate diffracted reproduction reference beams or illumination within the cover glass of the display. As an example, the diffraction efficiency of each grating is 50% for blue, 60% for green, and 70% for red. The bottom layer of the optical diffractive device is parallel to the cover glass of the display. The diffraction angle of the reproduced object beam for each color is −6°. As shown in Figures 13A, 13B, and 13C, the reproduction reference angles are 78.4° for blue light at 460 nm, 76.5° for green light at 520 nm, and 73.0° for red light at 640 nm. At 5°, the final object beam power in the cover glass of the display is 46.8% for blue, 33.1% for green, and 43.0% for red.

FIG. 12A illustrates an example optical diffraction device 1200 that includes three color diffraction gratings and corresponding reflective layers for individually diffracting three colors of light. For purposes of illustration, device 1200 is configured for blue light, green light, and red light.

Optical diffraction device 1200 includes a first diffraction component 1210 with a first grating 1212 for blue color, a second diffraction component 1220 with a second grating 1222 for green color, and a second diffraction component 1220 with a second grating 1222 for green color. a third diffractive component 1230 having a third diffraction grating 1232 for. Each of first grating 1212, second grating 1222, and third grating 1232 may be a holographic grating, such as a Bragg grating or a volume grating. Each of the first diffraction grating 1212, the second diffraction grating 1222, and the third diffraction grating 1232 can be independently recorded on and fixed to a recording medium, for example, a photosensitive polymer such as a photopolymer. .

The first diffractive component 1210, the second diffractive component 1220, and the third diffractive component 1230 can be stacked together on the field grating substrate 1202 along a direction, eg, the Z direction. Field grating substrate 1202 can be an optically transparent substrate, such as a glass substrate. Optical diffraction device 1210 may be in front of a display such as an LCOS, for example display 594 in FIG. 5H. For example, the optical diffractive device 1200 can be placed on the cover glass 1240 of the display through an interlayer or separated by a gap, eg, an air gap.

Similar to first diffractive component 1010, second diffractive component 1020, and third diffractive component 1030 of FIGS. 10A and 10B, first diffractive component 1210, second diffractive component 1220, and Each of the third diffractive components 1230 may include a respective substrate 1214, 1224, 1234 and a respective carrier film 1216, 1226, 1236 on either side of a respective diffraction grating 1212, 1222, 1232. A respective grating 1212, 1222, 1232 is between a respective substrate 1214, 1224, 1234 and a respective carrier film 1216, 1226, 1236. The respective substrates 1214, 1224, 1234 and the respective carrier films 1216, 1226, 1236 can be arranged in an order to reduce refractive index mismatch and thus Fresnel reflections. Each substrate 1214, 1224, 1234 can be a glass substrate that can have a refractive index the same as or close to that of field grating substrate 1202. Each carrier film 1216, 1226, 1236 can be a TAC film. The TAC film can have a lower refractive index than the photopolymer. In some examples, a respective substrate 1214, 1224 is placed in front of a carrier film 1216, 1226. Substrate 1234 is placed after carrier film 1236.

Adjacent layers or components within the optical diffraction device 1100 may be attached together using interlayers of one or more of OCA, UV-cured or heat-cured optical adhesives, optical contacts, or index-matching fluids. can. For example, a first diffractive component 1210 (eg, substrate 1214) can be coupled to field grating substrate 1202 through an intermediate layer 1201, eg, an OCA layer. The first diffractive component 1210 and the second diffractive component 1220, eg, carrier film 1216 and substrate 1224, can be attached together through another intermediate layer 1203, eg, an OCA layer. The second and third diffractive components 1220 and 1230, eg, carrier film 1226 and carrier film 1236, can be attached together through another intermediate layer 1205, eg, an OCA layer. Optical diffraction device 1200 (eg, substrate 1234) can be attached to a display cover glass 1240 through an interlayer 1207, eg, an OCA layer.

As shown in FIG. 12A, each of the first diffraction grating 1212, the second diffraction grating 1222, and the third diffraction grating 1232 transmits light of a corresponding color incident at a respective angle of incidence to each diffraction grating. It is configured to diffract light in the first order at different angles and in the zeroth order at each angle of incidence, and to transmit light of different colors at different angles of incidence, for example, due to Bragg selectivity. Therefore, there can be little or no crosstalk between the different colors of light that are individually diffracted by the corresponding diffraction gratings. Each color of light can be polarized. The polarization states of the first order diffracted light of different colors may be the same, for example s or p. The respective diffraction angles for light of different colors may be the same, eg substantially perpendicular.

As discussed above in FIGS. 13A, 13B, 13C, different angles of incidence θ _b , θ _g , θ _r (or reproduction reference angles) for different colors of light (blue, green, and red) can be, for example, Can be selected to be 78.4°, 76.5°, and 73.5°. Optical diffraction device 1200 can include a first reflective layer (or blocking layer) between first grating 1212 and second grating 1222. The first grating 1212 is configured to diffract blue light incident at a first angle of incidence θ _b to an angle of diffraction, e.g., the first order at 0° and the zero order at the first angle of incidence. has been done. The refractive index of the first reflective layer, e.g., is such that it completely reflects blue light diffracted at a first angle of incidence, but green light incident at a second angle of incidence θ _g . , and is configured to transmit red light incident at a third incident angle θ _r . For example, the refractive index of the first reflective layer is lower than the refractive index of the first reflective layer, eg, the layer immediately preceding the first grating 1212. The first reflective layer may be a suitable layer between the first grating 1212 and the second grating 1222. In some examples, the first reflective layer is a carrier film 1216, as shown in FIG. 12A. Total internal reflection occurs on the interface between first grating 1212 and carrier film 1216. Completely reflected blue light that is not diffracted (or transmitted) at the zero order is reflected back against the layer above the first reflective layer and absorbs light coated on the side of the optical diffraction device 1200. can be absorbed by the body 1204.

Optical diffraction device 1200 can include a second reflective layer (or blocking layer) between second grating 1222 and third grating 1232. The second grating 1222 is configured to diffract green light incident at a second angle of incidence θ _g to the first order at a certain diffraction angle, e.g. 0°, and to the zero order at a second angle of incidence. There is. The refractive index of the second reflective layer, e.g., is such that the refractive index of the second reflective layer completely reflects the green light diffracted at the second angle of incidence, but the red light incident at the third angle of incidence θ _r It is configured to transmit. For example, the refractive index of the second reflective layer is lower than the refractive index of the layer immediately preceding the second reflective layer. A second reflective layer may be a suitable layer between second grating 1222 and third grating 1232. In some examples, the second reflective layer is an intermediate layer 1205, as shown in FIG. 12A. Total internal reflection occurs on the interface between carrier film 1226 and intermediate layer 1205. Completely reflected green light that is not diffracted (or transmitted) at the zero order is reflected back to the layer above the second reflective layer and can be absorbed by the light absorber 1204.

Optical diffraction device 1200 can include a third reflective layer after third grating 1232 and before display cover glass 1240. The third grating 1232 is configured to diffract red light incident at a third angle of incidence θ _r to the first order at a certain diffraction angle, e.g. 0°, and to the zero order at a third angle of incidence. There is. The third reflective layer, e.g. the refractive index of the third reflective layer, is configured to completely reflect red light diffracted at the third angle of incidence. A third reflective layer may be a suitable layer between third grating 1232 and cover glass 1240. In some examples, the third reflective layer is an intermediate layer 1207 between the substrate 1234 and the cover glass 1240, as shown in FIG. 12A. Completely reflected red light that is not diffracted (or transmitted) in the zero order is reflected back to the layer above the second reflective layer and can be absorbed by the light absorber 1204.

The field grating substrate 1202 can be thick enough so that different colored reproduction reference light beams enter its edges of the field grating substrate 1202. Field grating substrate 1202 can also be configured to completely contain the reproduction reference light beam such that a viewer or observer cannot insert a finger or other object into the reproduction reference light beam. Therefore, the viewer cannot obstruct the reproduction reference light beam, which improves laser safety as the viewer cannot put his eyes (or reflective or focusing elements) into the full power reproduction reference light beam. be able to. Optical diffraction device 1200 with field grating substrate 1202 may be significantly more compact than if the reproduction reference light beam is incident from the air onto the front surface of optical diffraction device 1200.

As shown in FIG. 12A, field grating substrate 1202 can have a rectangular cross section in the XZ plane. Light of different colors enters the field grating substrate 1202 from the side. FIG. 12B illustrates another example optical diffraction device 1250 that includes a wedge-shaped field grating substrate 1252. The wedge angle between the side surface (or input surface of the light beam) 1251 of the substrate 1252 and the top layer 1253 of the substrate 1252 can be selected and/or the side surface can be AR coated, thus reducing optical diffraction. The optical path taken by any light beam returning from the device 1250 and display to the field grating substrate 1252 is blocked, attenuated, or directed as appropriate to reduce or eliminate reflections back into the optical diffraction device 1250 and display. be able to. Optical diffraction device 1250 can include a corresponding light absorber 1254 coated on the opposite surface, which can be shorter than light absorber 1204 of FIG. 12A.

FIG. 12C illustrates a further exemplary optical diffraction device 1270 that includes a field grating substrate 1272 with a wedge-shaped input surface 1271. Wedge-shaped input surface 1271 may be configured to reduce Fresnel losses of input light of different colors. Wedge-shaped input surface 1271 is configured such that input light of different colors is incident on input surface 1271 at substantially normal incidence and incident on corresponding gratings at different angles of incidence (or reproduction reference angles). obtain. Wedge-shaped input surface 1271 may be configured to refract input light of different colors to a desired angle for each color within the diffractive device and from a convenient direction and angle in air. For example, the wedge-shaped input surface 1271 may have a wedge angle such that the in-air angle moves the input beam parallel to the front face of the diffractive device or out of the space behind the front face of the diffractive device.

An AR coating can be formed on the front surface 1273 of the field grating substrate 1272 to reduce or eliminate reflection of ambient light back towards the viewer. An AR coating may also be formed on the back side of the optical diffraction device 1270 closest to the display to reduce or eliminate unwanted reflections of light reflected and/or diffracted from the display toward the viewer.

In some implementations, one or more layers within an optical diffractive device, e.g., optical diffractive device 1100 of FIG. 11, 1200 of FIG. 12A, 1250 of FIG. 12B, or 1270 of FIG. 12C, is slightly wedge-shaped. This can allow fine tuning of TIR and Fresnel reflection in each layer. The layer also reduces or eliminates the visibility of Newton's rings or interference fringes that may occur between any pair of substantially parallel surfaces within an optical diffraction device when using a narrowband light source, e.g., a laser diode. It can be configured as follows.

Exemplary Manufacturing Process FIG. 14A is a flowchart of an exemplary process 1400 for manufacturing an optical diffractive device that includes a diffractive structure and a corresponding color-selective polarizer. The optical diffraction device may be optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 5K, optical diffraction device 900 of FIGS. could be.

A first diffractive component for a first color is manufactured (1402). The first diffractive component can be the first diffractive component 910 of FIGS. 9A and 9B or 1010 of FIGS. 10A and 10B. The first diffractive component includes a first diffractive structure formed in the recording medium, such as B grating 912 in FIGS. 9A and 9B or B grating 1012 in FIGS. 10A and 10B. The first diffractive structure reproduces a first color that is incident on the first diffractive structure at a first diffraction efficiency, at a first diffraction angle, at a first angle of incidence, and in a first polarization state. The reference light (or the first color light) is configured to be diffracted. The first diffraction efficiency is determined by the fact that the first diffraction structure has a first color incident at a first angle of incidence with a second polarization state different from the first polarization state, e.g. due to polarization selectivity. or another different color of light. The first polarization state may be s-polarization and the second polarization state may be p-polarization.

The first diffractive structure may be a holographic grating, for example a volume grating or a Bragg grating. The thickness of the recording medium may be more than an order of magnitude greater than the wavelength of the first recording object beam, for example 30 times. In some examples, the first angle of incidence can be a Bragg angle. The first diffraction efficiency is determined by the first diffraction efficiency of the first diffraction structure, which is incident in the first polarization state or in the second polarization state at an angle of incidence different from the first angle of incidence, e.g. due to Bragg selectivity. The diffraction efficiency for diffracting light of one color or another different color can be substantially higher.

The recording medium can include a photosensitive material, such as a photopolymer or a photopolymer. The first diffractive structure may be formed by exposing the photosensitive material to a first recording object beam at a first recording object angle and simultaneously to a first recording reference beam at a first recording reference angle. can. The first recording object beam and the first recording reference beam may, for example, have the same wavelength from the same light source and the same first polarization state.

In some cases, the first color of light used for reproduction may include a wider or the same wavelength range as the first recording reference beam or the first recording object beam. For example, the first recording reference beam and the first recording object beam may be laser light beams, and the first color light for reproduction may be a laser diode light beam. In some cases, the first recording reference beam and the first recording object beam can correspond to a different color than the first color of the first color of light. For example, green laser light can be used to record the grating for red.

The first angle of incidence of the first color of light may be substantially the same as the first recording reference angle, and the first diffraction angle may be substantially the same as the first recording object angle. . In some examples, the first recording reference angle is in a range of 70 degrees to 90 degrees, such as in a range of 80 degrees to 90 degrees. In some examples, the first recording object angle ranges from -10 degrees to 10 degrees, such as from -7 degrees to 7 degrees, 0 degrees, or 6 degrees. In some examples, the sum of the first recording reference angle and the first recording object angle within the photosensitive material is substantially equal to 90 degrees.

The first diffractive structure can be fixed within the recording medium, for example by UV curing or heat curing. In some examples, the first diffractive component includes a carrier film, such as a TAC film, on the recording medium. In some examples, the first diffractive component includes a diffractive substrate, such as a glass substrate. A recording medium can be between the carrier film and the diffractive substrate.

A second diffractive component for a second color is manufactured (1404). The second diffractive component can be second diffractive component 920 of FIGS. 9A and 9B or 1020 of FIGS. 10A and 10B. The second diffractive component includes a second diffractive structure formed on the second recording medium, such as B grating 922 in FIGS. 9A and 9B or R grating 1022 in FIGS. 10A and 10B. The second diffractive structure reproduces a second color that is incident on the second diffractive structure at a second angle of incidence at a second angle of incidence and in a first state of polarization with a second diffraction efficiency. The reference light (or second color light) is configured to be diffracted. The second diffraction efficiency is such that the second diffraction structure is capable of absorbing light of a second color or another light incident in a second state of polarization at a second angle of incidence or an angle of incidence different from the second angle of incidence. It can be substantially higher than the diffraction efficiency for diffracting light of different colors.

The second diffractive structure can be manufactured in the same manner as the first diffractive structure, as described above. The first diffractive structure and the second diffractive structure can be manufactured independently. The second diffractive component can also include a carrier film and a diffractive substrate.

The first diffractive component and the second diffractive component may be configured such that the first diffraction angle and the second diffraction angle are substantially the same, such as substantially perpendicular, to each other. The first angle of incidence and the second angle of incidence may be substantially the same as each other.

A color selective polarizer is disposed between the first optical diffractive component and the second optical diffractive component (1406). The color sensitive polarizer can be GM filter 906 in FIGS. 9A and 9B or MG filter 1006 in FIGS. 10A and 10B. The optical diffractive structure can include a field grating substrate, such as substrate 902 of FIGS. 9A and 9B or substrate 1002 of FIGS. 10A and 10B. The first optical diffractive component, the color-selective polarizer, and the second optical diffractive component are arranged such that the first color of light and the second color of light are arranged in the first optical diffractive component before the second optical diffractive component. can be sequentially stacked on a field grating substrate such that it is incident on an optical diffractive component of the field grating. The color-selective polarizer may e.g. It can be configured to rotate the polarization states of the two colors of light. In some cases, the color selective polarizer can rotate the polarization state of the first color of light. In some cases, the color selective polarizer is configured not to rotate the polarization state of the first color of light.

In some implementations, an additional color selective polarizer is placed in front of the first diffractive component. For example, an additional color selective polarizer may be between the field grating substrate and the first diffractive component. The additional color selective polarizer may be BY filter 904 in FIGS. 9A and 9B or BY filter 1004 in FIGS. 10A and 10B. The additional color-selective polarizer may be arranged such that the light of the first color is incident on the first diffractive structure in the first polarization state, e.g. from the second polarization state to the first polarization state. is configured to rotate the polarization state of color light. In some cases, the additional color-selective polarizer is configured such that the polarization state of light of a second color is incident on the first diffractive structure in a second polarization state, e.g. The polarization state of the second color light can be rotated to a second polarization state. In some cases, the additional color-selective polarizer changes the polarization of the light of the second color such that the polarization state of the light of the second color is incident on the first diffractive structure in a second polarization state. It is configured not to rotate the state.

Adjacent components within an optical diffractive device can be attached together through an interlayer. The interlayer can be an OCA layer, a UV cured or heat cured optical adhesive, an optical contact, or an index matching fluid.

In some implementations, process 1400 can further include forming a third optical diffractive component. The third diffractive component includes a third diffractive structure formed in a third recording medium, such as the G grating 1032 of FIGS. 10A and 10B. The third diffractive structure reproduces a third color, the third diffractive structure being incident on the third diffractive structure at a third diffraction efficiency, at a third diffraction angle, at a third angle of incidence, and in a first polarization state. It is configured to diffract the reference light (or third color light). The third diffraction efficiency is such that the third diffraction structure is capable of absorbing light of a third color or another light incident in a third polarization state at an angle of incidence different from the second or third angle of incidence. The diffraction efficiency for diffracting light of different colors can be substantially higher.

The third diffractive structure can be manufactured in the same manner as the first diffractive structure, as described above. The first diffractive structure, the second diffractive structure, and the third diffractive structure can be manufactured independently. The third diffractive component can also include a carrier film and a diffractive substrate. The first diffractive component, the second diffractive component, and the third diffractive component have a first diffraction angle, a second diffraction angle, and a third diffraction angle that are substantially the same as each other, e.g. It can be configured to be substantially vertical. The first angle of incidence, the second angle of incidence, and the third angle of incidence may be substantially the same as each other.

A second color selective polarizer can be disposed between the second optical diffractive component and the third optical diffractive component. The second color sensitive polarizer can be the YG filter of FIGS. 10A and 10B. The second color-selective polarizer can be comprised of two or more sub-polarizers, such as RC filter 1008-1 and GM filter 1008-2 of FIGS. 10A and 10B. In some examples, the second color-selective polarizer is first attached onto the third diffractive component, and then the second color-selective polarizer is attached to the second diffractive component. be able to. In some examples, the second color-selective polarizer can be attached to the second diffractive component first, and then the third diffractive component can be attached to the second color-selective polarizer. Can be installed. The second color selective polarizer changes the polarization state of the third color light to a second polarization state such that the third color light is incident on the third diffractive structure in a first polarization state. The polarization state can be rotated from the polarization state to the first polarization state. The second color-selective polarizer changes the polarization state of the second color light, e.g., from the first polarization state to the second polarization state, without rotation of the polarization state of the first color light. It can be configured to rotate.

a third color-selective polarizer, such that the third optical diffractive component is between the second color-selective polarizer and the third color-selective polarizer; can be arranged sequentially. The third color selective polarizer may be the MG filter 1040 of FIGS. 10A and 10B. A third color-selective polarizer polarizes the third color light such that the diffracted first color light, second color light, and third color light have the same polarization state. For example, the polarization state of each of the first color light and the second color light is rotated from the second polarization state to the first polarization state without rotating the first polarization state. It is configured.

FIG. 14B is a flowchart of an exemplary process 1450 for manufacturing an optical diffractive device that includes a diffractive structure and a corresponding reflective layer. The optical diffraction device may be optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 5K, optical diffraction device 1100 of FIG. 11, or optical device 1200 of FIG. Alternatively, it may be 1270 in FIG. 12C.

A first optical diffractive component is formed (1452). The first diffractive component can be the first diffractive component 1110 of FIG. 11, 1210 of FIG. 12A, 12B, or 12C. The first diffractive component includes a first diffractive structure stored on a first recording medium. The first diffractive structure is configured to diffract light of a first color incident at a first angle of incidence to the first order at the first diffraction angle and to the zeroth order at the first angle of incidence. . The power of the first color light of the first order may be substantially higher than the power of the first color light of the zero order.

The first diffractive structure may be a holographic grating, for example a volume grating or a Bragg grating. The thickness of the recording medium may be more than an order of magnitude greater than the wavelength of the first recording object beam, for example 30 times. In some examples, the first angle of incidence can be a Bragg angle. The first diffraction efficiency is such that the first diffraction structure diffracts the first color of light or another different color of light at an angle of incidence different from the first angle of incidence, e.g. due to Bragg selectivity. can be substantially higher than the diffraction efficiency. Light incident at different angles of incidence can be transmitted through the first diffractive structure.

The recording medium can include a photosensitive material, such as a photopolymer or a photopolymer. The first diffractive structure, for example, directs the photosensitive material into the first recording object beam at the first recording object angle and simultaneously into the first recording object beam at the first recording reference angle, similar to step 1402 of FIG. 14A. It can be formed by exposure to a recording reference beam. The first recording object beam and the first recording reference beam may, for example, have the same wavelength and the same polarization state from the same light source. The first angle of incidence of the first color of light may be substantially the same as the first recording reference angle, and the first diffraction angle may be substantially the same as the first recording object angle. . In some examples, the first recording reference angle is in a range of 70 degrees to 90 degrees, such as in a range of 70 degrees to 80 degrees. In some examples, the first recorded object angle ranges from -10 degrees to 10 degrees, such as from -7 degrees to 7 degrees, 0 degrees, or 6 degrees. The first diffractive structure can be fixed within the recording medium, for example by UV curing or heat curing. In some examples, the first diffractive component includes a carrier film, such as a TAC film, on the recording medium. In some examples, the first diffractive component includes a diffractive substrate, such as a glass substrate. A recording medium can be between the carrier film and the diffractive substrate.

A second optical diffractive component is formed (1454). The second diffractive component can be second diffractive component 1120 of FIG. 11, 1220 of FIG. 12A, 12B, or 12C. The second diffractive component includes a second diffractive structure stored on a second recording medium. The second diffractive structure is configured to diffract light of a second color incident at a second angle of incidence to the first order at the second angle of diffraction and to the zero order at the second angle of incidence. . The power of the first order second color light may be substantially higher than the power of the zero order second color light.

The second diffractive structure can be manufactured in a similar manner as the first diffractive structure in step 1452. The first diffractive structure and the second diffractive structure can be manufactured independently. The second diffractive component can also include a carrier film and a diffractive substrate.

The first diffractive component and the second diffractive component may be configured such that the first diffraction angle and the second diffraction angle are substantially the same, such as substantially perpendicular, to each other. The first angle of incidence and the second angle of incidence are different from each other. The first angle of incidence and the second angle of incidence can be determined, for example, according to those described in FIGS. 13A-13C. In some examples, the first color of light has a smaller wavelength than the second color of light and the first angle of incidence is greater than the second angle of incidence.

A first reflective layer is disposed between the first diffractive structure and the second diffractive structure (1456). The first reflective layer can be reflective layer 1116 in FIG. 11 or 1216 in FIG. 12A, 12B, or 12C. The first reflective layer is arranged so that light of the first color that is not diffracted (or transmitted) in the zero order does not propagate to the display behind the optical diffraction device. The first color light is configured to completely reflect light of a first color incident at a first angle of incidence. The first reflective layer is configured such that light of a first color having a first angle of incidence does not completely reflect light of a second color having a second angle of incidence. a layer of the first optical diffractive component such that it is completely reflected by the interface between the layer of the first optical diffractive component and the layer of the first optical diffractive component that is directly adjacent to the first reflective layer. It can be configured as follows. The first reflective layer can be any suitable layer between the first and second diffractive structures. For example, the first reflective layer can be a carrier film for the first diffractive component.

A second reflective layer is disposed behind the second diffractive structure (1458). The second reflective layer can be reflective layer 1105 in FIG. 11 or 1205 in FIG. 12A, 12B, or 12C. The second reflective layer is arranged so that light of a second color that is not diffracted (or transmitted) in the zero order does not propagate to the display behind the optical diffraction device. It is configured to completely reflect light of a second color incident at a second angle of incidence so that it can be reflected at a second angle of incidence.

Light absorbers can be formed on the sides of the optical diffraction device. The light absorber can be light absorber 1104 in FIG. 11, 1204 in FIGS. 12A, 12C, or 1254 in FIG. 12B. The light absorber is configured to absorb fully reflected light of the first color and the second color.

In some implementations, a third optical diffractive component is formed that includes a third diffractive structure. The third diffractive component can be third diffractive component 1230 of FIG. 12A, 12B, or 12C. The third diffractive structure may be third diffractive structure 1232 of FIG. 12A, 12B, or 12C. The third diffractive structure is configured to diffract light of a third color incident at the third angle of incidence to a first order at the third angle of incidence and to a zero order at the third angle of incidence. There is. The power of the first order third color light may be substantially higher than the power of the zero order third color light. The first diffraction angle, the second diffraction angle, and the third diffraction angle may be substantially the same as each other. The third angle of incidence may be different from the first angle of incidence and the second angle of incidence. Each of the first reflective layer and the second reflective layer can be configured to transmit light of a third color having a third angle of incidence. A second reflective layer can be placed between the second and third diffractive structures. The third diffractive structure can be manufactured in a similar manner as the first diffractive structure in step 1452. The first diffractive structure, the second diffractive structure, and the third diffractive structure can be manufactured independently. The third diffractive component can also include a carrier film and a diffractive substrate.

A third reflective layer can be placed behind the third diffractive structure. The third reflective layer can be third reflective layer 1207 of FIG. 12A, 12B, or 12C. The third reflective layer is arranged such that light of a third color that is not diffracted (or transmitted) in the zero order is reflected back with respect to the previous layer of the third reflective layer and on the side of the optical diffraction device. The third color of light having a third angle of incidence is completely reflected so that it can be absorbed by the light absorber coated on the light absorber.

In some implementations, the first reflective layer includes a first carrier film of a first optical diffractive component. The second diffractive substrate of the second diffractive component is attached to the first carrier film of the first diffractive component by a first intermediate layer, for example an OCA layer. The second carrier film of the second diffractive component is attached to the third carrier film of the third optical diffractive component by a second intermediate layer, and the second reflective layer is attached to the third carrier film of the third optical diffractive component by a second intermediate layer. can include layers. A third reflective layer can be attached to the third diffractive substrate of the third diffractive component.

Process 1450 can include positioning the first diffractive component on the substrate in front of the first diffractive component. The substrate can be field grating substrate 1102 in FIG. 11, 1202 in FIG. 12A, 1252 in FIG. 12B, or 1272 in FIG. 12C. The substrate can include a front side and a back side. The front side of the first diffractive component can be attached to the back side of the substrate through an index matching material or OCA layer.

In some examples, the substrate includes a side surface that is angled relative to a back surface of the substrate, and the substrate is configured to receive a plurality of different colors of light at the side surface. The substrate may be configured such that light of a plurality of different colors is incident on the side surfaces at an angle of incidence substantially equal to 0 degrees and incident on the back surface at respective reproduction reference angles.

Implementations of the present disclosure can provide methods of manufacturing devices including optical diffractive devices and displays. The display may be display 594 in FIG. 5H, 594A in FIG. 5I, 594B in FIG. 5J, and 594C in FIG. 5K. The optical diffraction device may be optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 11, or optical device 1200 of FIG. 12A, 1250 of FIG. 12B, or 1270 of FIG. 12C.

The method can include forming an optical diffractive device according to process 1400 of FIG. 14A or process 1450 of FIG. 14B. In some implementations, an optical diffractive device can include one or more color-selective polarizers and one or more reflective layers for multiple different colors of light. Optical diffractive devices can be manufactured according to a combination of process 1400 and process 1450.

The method can further include arranging the optical diffractive device and the display such that the optical diffractive device is configured to diffract a plurality of different colors of light onto the display.

In some implementations, the optical diffraction device and the display can be arranged such that the back side of the optical device is separated from the front side of the display by a gap, eg, an air gap. The method can further include forming an anti-reflective coating on at least one of the front side of the display or the back side of the optical diffractive device.

In some implementations, the optical diffractive device and display can be placed by attaching the back side of the optical diffractive device onto the front side of the display through an interlayer. The interlayer is arranged in the optical diffraction device such that each of the plurality of different colors of light diffracted by the optical diffraction device in the zero order is completely reflected at the interface between the interlayer and the layers of the optical diffraction device. It can be configured to have a refractive index lower than that of the layer.

The optical diffraction device is configured to diffract a plurality of different colors of light at respective diffraction angles that are substantially the same as each other. Each of the respective diffraction angles ranges from -10 degrees to 10 degrees, such as from -7 degrees to 7 degrees, and can be 0 degrees, or 6 degrees. The display may be configured to re-diffract the diffracted colored light back through an optical diffraction device. An area of the optical diffraction device can cover an area of the display. The optical diffraction device can include a substrate in front of an optical device that can be configured to receive light of a plurality of different colors on a side of the substrate that is angled relative to a back surface of the substrate.

Implementations of the present disclosure can provide a method of operating an optical diffraction device. The optical diffraction device may be optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 11, or optical device 1200 of FIG. 12A, 1250 of FIG. 12B, or 1270 of FIG. 12C. The optical diffraction device is operable to convert an incident beam containing a plurality of different colors of light into individually diffracted colors of light.

Implementations of the present disclosure can provide a method of operating a system that includes an optical diffraction device and a display. The optical diffraction device may be optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 11, or optical device 1200 of FIG. 12A, 1250 of FIG. 12B, or 1270 of FIG. 12C. The display includes multiple display elements. The display may be display 594 in FIG. 5H, 594A in FIG. 5I, 594B in FIG. 5J, and 594C in FIG. 5K. The method can be performed by a controller, such as controller 112 of FIG. 1A or 592 of FIG. 5H.

The method includes transmitting at least one timing control signal to an illuminator such that the optical diffraction device converts the plurality of different colors of light into individually diffracted colors of light to illuminate the display. activating the illuminator to emit a plurality of different colors of light onto the optical diffraction device and, for each of the plurality of display elements of the display, the individually diffracted color light being reflected by the modulated display element; and transmitting at least one respective control signal for modulating the display element to form a multicolor three-dimensional light field corresponding to the respective control signal.

In some implementations, a method includes obtaining graphics data including respective primitive data for a plurality of primitives corresponding to an object in three-dimensional space, and for each of the plurality of primitives in a three-dimensional coordinate system. , determining the EM field contribution to each of the plurality of display elements of the display by calculating the electromagnetic (EM) field propagation from the plurality of display elements from the plurality of display elements for each of the plurality of display elements; generating a sum of EM field contributions to the display element and, for each of the plurality of display elements, for modulating at least one characteristic of the display element, respectively based on the sum of the EM field contributions to the display element; and generating a control signal. A polychromatic three-dimensional light field corresponds to an object.

In some implementations, the method includes sequentially modulating a display with information associated with a plurality of different colors for a series of time periods, each of the plurality of different colors of light being diffracted onto the display by an optical device. of a plurality of colors within each of a series of time periods, and reflected by the modulated display elements of the display to form a three-dimensional light field with each color corresponding to an object within each time period. controlling the illuminator to sequentially emit each of the lights to the optical device.

Multiple different colors of light can be diffracted by the optical device at substantially the same diffraction angle with respect to the display. The diffraction angle may be within the range of 0 degrees to 10 degrees.

The illuminator and the optical diffractive device may be configured such that a plurality of different colors of light are incident on the first optical diffractive component of the optical diffractive device at respective angles of incidence. Each of the respective angles of incidence are in the range of 70 degrees to 90 degrees. In some cases, the respective angles of incidence are different from each other. In some cases, the respective angles of incidence are substantially the same as each other.

An optical diffraction device can include multiple diffraction gratings for multiple different colors. The grating can include a transmission grating, a reflection grating, or a combination thereof. For example, each of the optical diffraction devices shown in FIGS. 9A-12C includes a corresponding transmission grating for a different color. In some implementations, the optical diffraction device can include a combination of transmission and reflection gratings that can be configured for different colors. Optical diffraction devices can be configured to diffract incident light toward the same direction or back in the opposite direction.

FIG. 15 illustrates an example optical device 1500 that includes a combination of transmission and reflection gratings and corresponding reflective layers for two respective colors to individually diffract light of the two colors. Understand. Optical device 1500 includes a first diffractive component 1510 having a first diffraction grating 1512 for blue color and a second diffraction component 1520 having a second diffraction grating 1522 for green color. I can do it. Each of the first grating 1512 and the second grating 1522 may be a holographic grating, such as a Bragg grating or a volume grating. However, while the first grating 1512 for blue is configured to be a transmission grating that diffracts the blue light in the forward direction with respect to the blue light incident on the grating 1512, the first grating 1512 for blue The second diffraction grating 1522 is configured to be a reflection grating that reflects the green light incident on the grating 1522 backward. Each of the first diffraction grating 1512 and the second diffraction grating 1522 can be independently recorded and fixed to a recording medium, for example a photosensitive material such as a photopolymer.

The first diffractive component 1510 and the second diffractive component 1520 can be stacked together on the field grating substrate 1502 along a direction, eg, the Z direction. Field grating substrate 1502 can be an optically transparent substrate, such as a glass substrate. Optical diffraction device 1500 may be in front of a display such as an LCOS, eg, display 594 in FIG. 5H, 594A in FIG. 5I, 594B in FIG. 5J, or 594C in FIG. 5K. For example, the optical diffractive device 1500 can be placed on the cover glass 1530 of the display through an interlayer or separated by a gap, eg, an air gap.

Similar to the first diffractive component 1110 and the second diffractive component 1120 of FIG. can include respective substrates 1514, 1524 and respective carrier films 1516, 1526. A respective grating 1512, 1522 is between a respective substrate 1514, 1524 and a respective carrier film 1516, 1526. Each substrate 1514, 1524 can be a glass substrate that can have a refractive index the same as or close to that of field grating substrate 1502. Each carrier film 1516, 1526 can be a TAC film. The TAC film can have a lower refractive index than the photopolymer used to record the gratings 1512 and 1522. Adjacent layers or components within the optical diffraction device 1500 may be attached together using interlayers of one or more of OCA, UV-cured or heat-cured optical adhesives, optical contacts, or index-matching fluids. can. For example, a first diffractive component 1510 (eg, substrate 1514) can be coupled to field grating substrate 1502 through an intermediate layer 1501, eg, an OCA layer. The first diffractive component 1510 and the second diffractive component 1520, eg, carrier film 1516 and substrate 1524, can be attached together through another intermediate layer 1503, eg, an OCA layer. Optical diffraction device 1500 (eg, carrier film 1526) can be attached to a display cover glass 1530 through an interlayer 1505, eg, an OCA layer.

As shown in FIG. 15, the first diffraction grating 1512 receives blue light incident at a first incident angle θ _b , e.g., 78.4°, at a respective diffraction angle, e.g., perpendicularly to the display. The first order is configured to diffract the zero order at each angle of incidence and transmit green light at different angles of incidence, for example for Bragg selectivity. Therefore, there can be no crosstalk between the different colors of light that are individually diffracted by the corresponding diffraction gratings. Each color of light can be polarized. The polarization states of the different colored light diffracted in the first order may be the same, for example s or p.

Optical diffraction device 1500 can include a first reflective layer (or blocking layer) between first grating 1512 and second grating 1522. The first grating 1512 diffracts blue light incident at a first angle of incidence θ _b , e.g., 78.4°, into the first order at an angle of diffraction, e.g., 0°, and into the zero order at the first angle of incidence. It is configured to cause diffraction to occur. The first reflective layer, e.g., the refractive index of the first reflective layer is such that it completely reflects blue light diffracted at a first angle of incidence, but transmits green light incident at a second angle of incidence. It is configured to allow For example, the refractive index of the first reflective layer is lower than the refractive index of the first reflective layer, eg, the layer immediately preceding the first grating 1512. The first reflective layer may be a suitable layer between the first grating 1512 and the second grating 1522. In some examples, the first reflective layer is a carrier film 1516, as shown in FIG. 15.

Optical diffraction device 1500 can include a second reflective layer after second grating 1512 and before display cover glass 1530. The second reflective layer can be an intermediate layer 1505 and can be configured, for example, to fully reflect green light back to the second grating 1512. The second grating 1512 then redirects the green light incident at a second angle of incidence θ _g , e.g. 76.5°, back towards the display to first order at a diffraction angle, e.g. 0°. The optical diffraction device 1500 is configured to diffract back to the zeroth order at a second angle of incidence.

The completely reflected blue light by the reflective layer 1516 and the zero-order transmitted green light are behind the optical diffractive device 1500 to the sides of the optical diffractive device 1500. As illustrated in FIG. 15, the side surfaces are coated with a light absorber 1504, e.g., a black coating, and the corresponding transmission and reflection gratings 1512 and 1522 provide zero-order blue light and green light. can absorb light.

Each of the optical diffractive devices with a color-selective polarizer (e.g., as illustrated in FIGS. 9A-10B) and the optical diffractive device with a reflective layer (e.g., as illustrated in FIGS. 11-12C and 15). ) can be considered as a one-dimensional beam expander. A one-dimensional beam expander converts an input beam with a certain width and a certain height into the same width and a greater height, or the same height and a greater height, for example, by diffracting the input beam at one or more diffraction angles. It can be configured to expand into an output beam having any of a large width.

The techniques described herein can also be used to expand an input beam into an output beam that is wider and higher than the input beam, for example, by two-dimensional beam expansion. Two-dimensional beam expansion can be achieved by using a two-dimensional beam expander (or dual beam expander) having at least two one-dimensional beam expanders in series. For example, the first one-dimensional beam expander is configured to expand the input beam in a first dimension, either width or height, to produce an intermediate beam that is wider or taller than the input beam in the first dimension. Can be configured. The second one-dimensional beam expander is configured to expand the intermediate beam in a second dimension, either height or width, to produce an output beam that is taller or wider than the intermediate beam in the second dimension. can do. Thus, the output beam can be wider and taller than the input beams of the first and second dimensions.

In such a two-dimensional beam expander configuration, one or both of the one-dimensional beam expanders can use color selection technology and one or both of the one-dimensional beam expanders can use reflective layer technology. can be used. Each one-dimensional dilator may use any of the detailed embodiments herein, including reflective or refractive diffractive elements, or a combination of reflective and refractive diffractive elements. The one-dimensional beam expanders can be positioned in a sequential order in any suitable arrangement or configuration.

In some implementations, the intermediate beam between two such one-dimensional dilators is made using a free-space aerial geometry, or made of e.g. glass or acrylic, and the geometry of the substrates of both dilators and a monolithic or segmented substrate embodying functionality from the first one-dimensional dilator to the second one-dimensional dilator. This coupling can be achieved using one or more coupling elements between the two one-dimensional dilators. The coupling element may include a thin film element of a mirror, a plurality of mirrors, or a mirror and a beam splitting dichroic component, or an additional diffractive element. The coupling element takes the collinear collimated output light of the two or more colors from the first one-dimensional expander and combines the collinear collimated output light of the two or more colors with the collinear collimated output light of the two or more colors. into independent collimated but non-collinear intermediate beams, each with the color-dependent angular input requirements (if any) of the second one-dimensional expander for one of the colors. can be fulfilled. Similarly, the first one-dimensional dilator can have as input the collinear collimated outputs of two or more light sources (e.g., laser diodes), each having a different color, or each having a different color. It is possible to have as input two or more independent collimated, but non-collinear intermediate beams of one color from two or more light sources.

Display Zero-Order Light Suppression A display (eg, LCoS) includes an array of display elements (eg, pixels or phasels). There are gaps between display elements on the display. The gap occupies a portion of the area of the display, for example in the range of 5% to 10%. The gaps can be considered dead gaps because the display materials (eg, liquid crystals) in these gaps are not controlled by input control signals and therefore holographic information cannot be input into these gaps. In contrast, holographic information can be input to a display element that is controlled (or modulated) to diffract light to reconstruct a holographic scene corresponding to the holographic information.

FIG. 16 illustrates an example 1600 of incident light 1620 incident on a display 1610. Display 1610 may include display 114 of FIG. 1A, display 156 of FIG. 1B, display 512 of FIG. 5A, display 524 of FIG. 5B, display 534 of FIG. 5C, display 544 of FIG. 5D, display 564 of FIG. 574, display 584 of FIG. 5G, display 594 of FIG. 5H, display 594A of FIG. 5I, display 594B of FIG. 5J, display 594C of FIG. 5K, display 600 of FIG. 6A, or display 650 of FIG. 6B. Other display arrangements are also possible.

As an example, display 1610 may be an LCoS made of liquid crystal. Display 1610 includes an array of display elements 1612 (eg, display elements 160 of FIG. 1B) separated by gaps 1614. Each display element 1612 may have a square (or rectangular or any other suitable) shape with an element width 1613, for example 5 μm. Display element 1612 may also be any other suitable shape, such as a polygon. Adjacent display elements 1612 are separated by a gap 1614 with a gap size 1615, eg, less than 0.5 μm.

The incident light 1620 can be a collimated light beam that can have a beam size larger than the entire area of the display 1610 so that the incident light 1620 can illuminate the entire area of the display 1610. When incident light 1620 is incident on display 1610 at an angle of incidence θ _i , a first portion of incident light 1620 (e.g., 90%-95% of light 1620) illuminates display element 1612 and a first portion of incident light 1620 illuminates display element 1612 . A portion of 2 (eg, 5% to 10% of light 1620) illuminates gap 1614. When the display element 1612 is modulated with holographic information (e.g., a hologram corresponding to holographic data), e.g., by a voltage, a first portion of the incident light 1620 is modulated in the first order with a diffraction angle θ _d . The light can be diffracted by the displayed display element 1612 and become diffracted primary light 1622 .

The diffracted primary light 1622 forms a holographic light field, which may be a reconstruction cone (or truncated cone) 1630 with a viewing angle θ _a . The viewing angle θ _a depends on one or more characteristics of the display 1610 (eg, element pitch 1613) and one or more wavelengths of the incident light 1620. In some examples, half of the viewing angle θ _a is within the range of 3° to 10°, such as 5°. For example, for pitch d = 3.7 μm, the viewing angle θ _a is approximately 7° in air for blue light (λ = 460 nm), and in air for red light (λ = 640 nm). It is about 10°. Light with a larger wavelength corresponds to a larger viewing angle.

Since the gap 1614 of the display 1610 is not modulated by any holographic information, the display 1610 in the gap 1614 acts like a reflector. When the second portion of the incident light 1620 is incident on the gap 1614, the second portion of the incident light 1620 can be reflected at the gap 1614 with a reflection angle θ _r having the same absolute value as the angle of incidence θ _i . can. In the present disclosure herein, "A is the same as B" means whether the absolute value of A is the same as the absolute value of B and the direction of A is the same as or different from the direction of B. Show that it can be The reflected second portion of the incident light 1620 can be considered at least a portion of the display zero order light 1624. If the incident angle θ _i is less than half of the apex angle θ _a , e.g. θ _i =0°, the display zero-order light 1624 may appear undesirably within the reconstruction cone, which contributes to the effect of the holographic scene. can have an impact.

The display zero order light may also include any other unwanted light from the display, such as light diffracted at a gap, reflected light from a display element, or reflected light from a display cover on the display. Higher order display zero order light 1624 may include diffracted light at the gap. In some implementations, display 1610 is configured to suppress higher order display zero-order light, for example, by including irregular or non-uniform display elements having different sizes. The display elements may have no periodicity and form a Voronoi pattern, for example, as illustrated in FIG. 6A.

In the present disclosure herein, for purposes of illustration only, the reflected second portion of the incident light is considered to be representative of the display zero order light.

17A-17B illustrate examples 1700, 1750 of display zero order light within a holographic scene displayed on a projection screen (FIG. 17A) and to a viewer's eye (FIG. 17B). Collimated input light 1720 is combined by optical device 1710 to illuminate display 1610 at normal incidence, ie, θ _i =0°. Optical device 1710 can be a waveguide, beam splitter, or optical diffraction device. For purposes of illustration, optical device 1710 is an optical diffraction device, such as device 598 of FIG. 5H, which includes grating 1714 formed on substrate 1712. However, as mentioned above, reflective optical devices may be used.

A first portion of input light 1720 is incident on display element 1612 of display 1610 that is modulated with holographic information and is diffracted by display element 1612 into diffracted primary light 1722. A second portion of the input light 1720 enters the gap 1614 of the display 1610 and is reflected from the gap 1614 and becomes at least a portion of the display zero order light 1724. The diffracted primary light 1722 propagates in space to form a reconstruction cone of viewing angle, for example 10°. Since the angle of incidence, e.g., 0°, is less than half of the viewing angle, e.g., 5°, the display zeroth order light 1724 propagating with the same angle of reflection as the angle of incidence, e.g., 0°, will fall within the reconstruction cone. be.

As illustrated in FIG. 17A, the diffracted primary light 1722 forms a three-dimensional holographic scene, with two-dimensional cross-sections 1732 spaced apart from the display 1610 along a direction perpendicular to the display 1610. It may be viewed on a dimensional (2D) projection screen 1730. Display zero order light 1724 appears to be collimated zero order light 1734 as an undesired image (eg, having a rectangular shape) within holographic scene 1732. As illustrated in FIG. 17B, the diffracted primary light 1722 forms a holographic scene 1762 at the eye of the viewer 1760. Display zero order light 1724 is focused by the eye lens of viewer 1760 and appears as a focused zero order light 1764 as an unwanted spot within holographic scene 1762.

In order to improve the effectiveness of the reconstructed holographic scene and therefore the performance of the display system, it is desirable to suppress (or even eliminate) display zero-order light in the reconstructed holographic scene. Implementations of the present disclosure provide multiple techniques for suppressing (or even eliminating) display zero-order light in a reconstructed holographic scene, e.g., five techniques as described below. . The techniques can be applied individually or in combination.

The display zero-order light can be suppressed with light suppression efficiency in the reconstructed holographic scene. The light suppression efficiency is calculated from 1 to the amount of display zero-order light in a holographic scene with suppression using the techniques described herein and the amount of display zero-order light in a holographic scene without suppression. is defined as the ratio of In some examples, the light suppression efficiency exceeds a predetermined percentage, such as 50%, 60%, 70%, 80%, 90%, or 99%. In some examples, the light suppression efficiency is 100%. That is, in the holographic scene, all display zero-order light is excluded.

In a first technique, termed "phase calibration", the phase of a display element of a display can be adjusted to have a predetermined phase range, for example [0,2π]. In this way, the signal-to-noise ratio (S/N) between the holographic scene formed based on the calibrated phase and the display zero-order light can be increased.

In a second technique, referred to as "zero-order beam divergence," the display zero-order light beam is diverged by an optical defocusing device (e.g., a concave lens) to lower the It has power density. In contrast, holograms are preconfigured such that a collimated beam of light incident on a display element modulated by the hologram is diffracted into a focused beam of light. The focused light beam is refocused by an optical defocusing device to form a holographic scene with higher power density. Therefore, the display zero order light beam is diluted or suppressed in the holographic scene.

In a third technique, referred to as "zero-order light deviation," the display zero-order light deviates from the holographic scene, as illustrated in FIGS. 19A-19C, 20A-20B, 21, and 22. There is. The optical device is configured to combine the input light to illuminate the display at an angle of incidence greater than half the viewing angle of the reconstructed cone forming the holographic scene. Display zero order light propagates away from the display with an angle of reflection that is the same as the angle of incidence. The hologram corresponding to the holographic scene is preconfigured in such a way that the diffracted primary light goes away from the display and forms a reconstruction cone as it would at an angle of incidence of 0°. Therefore, the display zero-order light deviates from the reconstruction cone and therefore from the holographic scene.

In a fourth technique, termed "zero-order light interception," the display zero-order light is first deviated from the diffracted first-order light according to the third technique, as illustrated in FIGS. 23A-23B. , which is then blocked (or absorbed) by an optical blocking component, for example an anisotropic optical element such as a metamaterial layer or a louvered film. The optical blocking component is configured to transmit a light beam having an angle less than a predetermined angle and to block a light beam having an angle greater than a predetermined angle. The predetermined angle may be less than the angle of incidence of the input light and greater than half the viewing angle of the reconstruction cone.

In a fifth technique, termed "zero-order light redirection," the display zero-order light is first deviated from the diffracted first-order light according to the third technique, as illustrated in FIGS. 24-33. , which is then redirected further away from the diffracted primary light by an optical diffraction component, e.g. a diffraction grating. When the input light includes light of different colors, either simultaneously or sequentially, as illustrated in FIGS. 30A-30B, 31A-31B, 32, and 33, the optical diffraction component may include one or more corresponding diffraction gratings configured to diffract light of different colors toward different directions in a plane or in space to reduce color crosstalk.

The above five techniques are mainly used to suppress the overall reflected zero-order display zero-order light. In a sixth technique, the display is configured to suppress the overall zero order light of the higher order display, for example by using irregular or non-uniform display elements with different sizes and/or shapes. has been done. The display elements may have no periodicity and form a Voronoi pattern, or a Voronoi patterned display element. In some implementations, the display may be display 600 of FIG. 6A or display 650 of FIG. 6B.

The first five techniques will be explained in more detail below.

First Technique - Phase Calibration Phase calibration is a technique that can increase the contrast of a display, e.g. by deriving the calculated direct current (DC) term of the hologram, which can be done by software or program instructions. It can be implemented by Phase calibration can achieve accuracy beyond device calibration, which may be bad or unknown.

In some implementations, the hologram includes a phase of each of the display elements of the display. As mentioned above, each phase may be the calculated EM contribution from one or more corresponding objects to each display element. According to the phase calibration technique, the holograms have their respective phases adjusted (e.g., (scaling and/or shifting).

The phase of each is expressed as
can be adjusted according to
During the ceremony
represents the initial phase value of each phase,
represents the adjusted phase value of each phase, A and B are constants of each phase, A is at [0,1] and B is at [0,2π]. In some examples, A is the same for all display elements. In some examples, B is the same for all display elements. In some examples, A is different for different display elements. In some examples, B is different for different display elements.

In a fully calibrated and linearized display system, the value (1,0) of the pair (A,B) gives the best contrast by proving the highest diffraction efficiency of the input hologram. function optimally. However, due to non-linear LC curves and inaccurate calibration of the display, the phase of each of the display elements is typically not within [0,2π], thus reducing display contrast. Since the input light is the same, the display zero order light is the same. Improving the diffraction efficiency of the hologram can result in higher display contrast and higher signal-to-noise ratio of the holographic scene.

According to the phase calibration technique, the display contrast can be improved by scaling and shifting the respective phases in the phase coordinate system, so that the respective phases are within a certain range, e.g. exactly [0 , 2π]. In some cases, the range of each adjusted phase may be smaller or larger than the 2π range, depending on the calibration and the maximum phase shift of the working LC. Therefore, for each display, there may be a pair (A, B) that yields the highest diffraction efficiency and yields the highest signal-to-noise ratio.

The phase of each of the display elements can be adjusted by adjusting constant A and constant B to maximize the light suppression efficiency of the holographic scene. The light suppression efficiency may be greater than a predetermined percentage, such as 50%, 60%, 70%, 80%, 90%, or 99%.

In some implementations, constants A and B are adjusted by a machine learning algorithm, such as a machine vision algorithm or an artificial intelligence (AI) algorithm. In machine vision algorithms, holograms are designed to create pseudo-random points focused on a flat, transparent diffuse screen at a certain distance from the display. A hologram is then computed for each of the three primary colors red, green, and blue (RGB) such that the RGB reconstructed points are perfectly aligned on that plane. The algorithm is then set to find a pair of values (A, B) for each color such that the display contrast is at an acceptable level. At the beginning of a pair of values (A,B), e.g. [1,0], a camera at a certain distance takes a picture of the pattern on the screen. In the captured image, the brightness of all points (X) is averaged and one small area (Y) above the background noise is also measured. Calculate the ratio of X/Y and check if it is greater than a certain value. If not, the value pair (A, B) is changed and the process is automatically repeated until an acceptable value pair (A, B) is determined.

Second Technique - Zero-Order Beam Divergence FIG. 18 illustrates an example system 1800 for suppressing display zero-order light in a holographic scene displayed on a projection screen 1830 by diverging the display zero-order light beam. Illustrate. A beam splitter 1810 is positioned in front of the display 1610 and combines a collimated input light beam 1820 to illuminate the display 1610 at normal incidence. A first portion of the light beam 1820 is diffracted by the holographically modulated display element into a diffracted first order light beam 1822, and a second portion of the light beam 1820 is diffracted by the display element modulated by the hologram into a diffracted first order light beam 1822, and a second portion of the light beam 1820 is diffracted by the display element modulated by the hologram into a diffracted first order light beam 1822. into the display zero order light beam 1824. An optical diverging component, eg, concave lens 1802, is positioned downstream of beam splitter 1810 and in front of projection screen 1830. In some examples, the optical diverging component is located further from the projection screen 1830 than the concave lens 1802 such that the collimated light beam is first focused and then diverged toward the projection screen 1830. including a convex lens arranged.

As display zero order light beam 1824 emerges from display 1610, display zero order light beam 1824 is collimated. Accordingly, when display zero order light beam 1824 passes through concave lens 1802, display zero order light beam 1824 is diverged by concave lens 1802, as illustrated in FIG. Accordingly, the power density of the divergent display zero-order light beam 1824 is reduced or diluted over the divergent beam area compared to the power density of the original collimated input light beam 1820.

According to a second technique, the holograms (or their respective phases) modulating the display elements of display 1610 are preconfigured such that the diffracted primary light beam 1822 is focused as it emerges from display 1610. be able to. The degree of convergence is configured to correspond to the degree of divergence of the concave lens 1802. That is, the divergence of the concave lens is compensated by the configured convergence. Therefore, when the focused diffracted primary light beam 1822 passes through the concave lens 1802, the diffracted primary light beam 1822 is the same as the projection screen 1830 without the hologram and the preconfiguration of the concave lens 1802. The top is collimated to form a reconstructed holographic scene 1832. Therefore, the reconstructed holographic scene 1832 has the same power density as the collimated input light beam 1820. In contrast, the display zero order light beam 1834 is reduced in power density and is diverged and smeared (or diluted) across the projection screen 1830. Projection screen 1830 is spaced from display 1610 by a specified distance, eg, 50 cm. Display zero order light beam 1834 is dark and can appear like background noise within holographic scene 1832. In such a manner, the light suppression efficiency can be increased, for example to over 99%, and the signal-to-noise ratio of the holographic scene 1832 can be increased.

In some implementations, the hologram is preconfigured by adding a corresponding phase to each of the display elements of display 1610. The respective phases of the display elements may be their respective phases adjusted according to the first technique - phase calibration. The corresponding phase for each of the display elements is
It is expressed as,
During the ceremony,
represents the corresponding phase for the display element, λ represents the wavelength of the input light 1820, f represents the focal length of the optically diverging component (e.g., concave lens 1802), and x and y represent the 2D display element. represents the coordinates of the display element in the coordinate system, and a and b represent constants. The pair of values (a, b) can be adjusted based on the application, for example to introduce astigmatism in people whose eyes suffer from astigmatism. If a is the same as b, e.g. a=1 and b=1, then the corresponding phase defocusing effect is circular; if a is different from b, e.g. a=1 and b=0 For .5, the defocus effect is elliptical and can be matched to a 2:1 anamorphic focusing lens. If either a=0 or b=0, but not both, the defocus effect produces a line focus rather than an area focus, which can be matched to a cylindrical focus lens.

In some implementations, holograms are pre-defined by adding virtual lenses of the constituent cones when designing (or simulating) a holographic scene in a 3D software application such as Unity, e.g., application 106 of FIG. 1A. It is configured. The constituent cones are described in further detail in FIGS. 20A-20B. The diffracted primary light beam 1822 forms a reconstruction cone with a viewing angle, and the constituent cone corresponds to the reconstruction cone and has an apex angle that is the same as the viewing angle. In the simulation, the configuration cone can be moved relative to the display in the global 3D coordinate system along a direction perpendicular to the display with a distance corresponding to the focal length of the optically diverging component. The construction cone can only be moved once for all objects within the reconstruction cone. Holographic data, eg, a primitive list of objects, is then generated based on the moved configuration cone in the global 3D coordinate system.

Third Technique - Zero-Order Light Deviation As explained above in Figures 16 and 17A-17B, the reconstruction cone of the holographic scene (or holographic content) has a viewing angle that depends on the display and the wavelength of the input light beam. has. If the display zero-order light is allowed to deviate outside the reconstruction cone, the holographic scene can be observed without the display zero-order light.

FIG. 19A illustrates an example system 1900 of display zero-order light in a holographic scene when the display 1610 is illuminated with collimated input light 1920 at normal incidence, i.e., θ _i =0°. . Optical device 1910 combines collimated input light 1920 to illuminate display 1610 at normal incidence. In some implementations, as illustrated in FIG. 19A, optical device 1910 includes a waveguide device, such as the waveguide device of FIG. This is a wave tube device 588.

A first portion of input light 1920 is incident on a display element of holographically modulated display 1610 and is diffracted by the display element into diffracted first order light 1922 . A second portion of input light 1920 enters a gap in display 1610 and is reflected at the gap and becomes at least a portion of display zero order light 1924. The diffracted primary light 1922 propagates in space to form a reconstruction cone of viewing angle, for example 10°. Since the angle of incidence, e.g., 0°, is less than half of the viewing angle, e.g., 5°, the display zero-order light 1924 propagating at the same angle of reflection as the angle of incidence, e.g., 0°, will fall within the reconstruction cone. be. As illustrated in FIG. 19A, the diffracted primary light 1922 forms a holographic scene 1932 on a two-dimensional (2D) projection screen 1930. Display zero order light 1924 appears to be collimated zero order light 1934 as an undesired image within holographic scene 1932.

FIG. 19B illustrates an example 1950 of suppressing display zero-order light in a holographic scene displayed on projection screen 1930 by directing (or diverting) the display zero-order light from the holographic scene. Unlike optical device 1910, optical device 1960, formed on substrate 1962 and including in-coupler 1966 and out-coupler 1964, couples collimated input light 1920 to display display 1610 at an angle of incidence θ greater than 0°. It is configured to irradiate at _i . Upon reflection, display zero order light 1974 emerges from display 1610 at a reflection angle θ _r that is the same as the angle of incidence θ _i .

According to a third technique, the holograms (or their respective phases) modulating the display elements of display 1610 can be preconfigured such that the diffracted primary light 1972 emerges from display 1610 at normal incidence. That is, deviations in the angle of incidence are compensated by the constructed hologram. Therefore, the diffracted primary light beam 1972 forms a reconstruction cone that appears as a reconstructed holographic scene 1976 on the projection screen 1930, just as it would when the angle of incidence was normal incidence. If the angle of incidence, e.g. 6°, is greater than half the viewing angle of the reconstruction cone, e.g. 5°, the display zero order light 1974 may deviate or shift from the reconstruction cone. Thus, as illustrated in FIG. 19B, a shifted display zero order image 1978 formed by display zero order light 1974 may be outside of the holographic scene 1976 on the projection screen 1930. Similarly, as illustrated in FIG. 19C, when viewed by viewer 1990, display zero-order spot 1994 formed by display zero-order light 1974 appears to the viewer's 1990 eye by diffracted first-order light 1972. It may be outside the formed holographic scene 1992. By configuring the direction of the angle of incidence, the display zero-order light can be shifted up and down or left and right in space.

In some implementations, the hologram is preconfigured by adding a corresponding phase to each of the display elements of display 1610. The respective phases of the display elements may be their respective phases adjusted according to the first technique - phase calibration. The corresponding phase for each of the display elements is
It is expressed as,
During the ceremony,
represents the corresponding phase for the display element, λ represents the wavelength of the input light 1920, x and y represent the coordinates of the display element in the 2D display coordinate system (or 3D coordinate system), and θ represents the incident Represents an angle corresponding to angle θ _i , for example, θ=θ _i .

In some implementations, the hologram is preconfigured by adding a virtual prism of the configuration cone when designing (or simulating) the holographic scene in a 3D software application such as Unity, e.g., application 106 of FIG. 1A. has been done.

FIG. 20A shows an example 2000 of a configuration cone 2020 and a reconstruction cone 2030 for a display 2002 and an optical device 2010 in a 3D coordinate system of a 3D software application. Optical device 2010 can be a light device, such as optical diffraction device 598 of FIG. 5H, which includes grating 2014 formed on substrate 2012.

As illustrated in FIG. 20A, optical device 2010 couples light 2040 to illuminate display 2002 at an angle of incidence greater than 0° rather than normal incidence, which is a reflection of the angle of incidence relative to the 3D coordinate system. is effectively the same as rotating configuration cone 2020 (along with all objects within configuration cone 2020, including object 2022) by a corresponding (eg, the same) angle. In some implementations, configuration cone 2020 is rotated in the original 3D coordinate system. In some implementations, the original 3D coordinate system is rotated, but the configuration cone 2020 is not. Once the configuration cone 2020 in the 3D coordinate system is set, objects can be placed in the configuration cone 2020 without individually changing the vertices of the primitives. Therefore, the simulated reconstruction cone 2030 (with all reconstructed objects, including reconstructed object 2032) and display zero-order light 2042 are the same relative to the 3D coordinate system for display 2002. Rotated by reflection angle. That is, display zero order light 2042 can appear in a holographic scene when viewed by a viewer.

FIG. 20B illustrates an example 2050 of adjusting the construction cone 2020 of FIG. 20A to construct a hologram that corresponds to a holographic scene in a 3D coordinate system of a 3D software application. The configuration cone 2020 (along with the designed objects including the object 2022) can be rotated at a rotational angle relative to the surface of the display 2002 in a 3D coordinate system. The rotation angle corresponds to an angle of incidence (e.g., identical be). The configuration cone 2020 can be adjusted only once for every designed object. Holographic data, eg, a primitive list of objects, is then generated based on the adjusted configuration cone 2060 in the global 3D coordinate system. A hologram is then generated based on the holographic data.

Thus, when optical device 2010 couples input light 2040 to illuminate display 2002 at an angle of incidence, a first portion of input light 2040 is diffracted by the preconfigured hologram-modulated display element. The diffracted primary light forms a reconstruction cone 2070 (with reconstructed objects including reconstructed objects 2072 of designed objects 2062) perpendicular to the display 2002. Reconstruction cone 2070 has a viewing angle θ _v . In contrast, the second portion of the input light 2040 is reflected at the gap without any preconfigured hologram modulation and emerges from the display at a reflection angle θ _r identical to the incident angle θ _i It becomes zero-order light 2042. Therefore, when the angle of incidence θ _i is greater than half the viewing angle, i.e., θ _i >θ _v /2, the display zero-order light 2042 is transmitted to the reconstruction cone 2070 and thus when viewed by the viewer. Located outside of the holographic scene.

Input light 2040 may be transmitted in any suitable manner, for example, by an in-coupler such as in-coupler 1966 of FIG. 19B, by a prism as illustrated in FIG. 21, or by a wedge-shaped substrate as illustrated in FIG. can be coupled to optical device 2010 by.

FIG. 21 illustrates an example 2100 in which collimated input light 2120 is coupled to an optical device 2110 through a coupling prism 2111 to illuminate a display 1610 at an angle of incidence to suppress display zero-order light in a holographic scene. Understand. Optical device 2110 includes a grating 2114 on a substrate 2112. Coupling prism 2111 couples input light 2120 to substrate 2112 which directs input light 2120 towards grating 2114 . Grating 2114 diffracts input light 2120 outward toward display 1610 at an angle of incidence. The hologram is arranged such that the diffracted first order light 2122 exits the display 1610 and surrounds normal incidence, forming a reconstruction cone, while the display zero order light 2124 exits the display 1610 at the same angle of reflection as the angle of incidence. Preconfigured. If the angle of incidence is greater than half the viewing angle of the reconstruction cone, the display zero order light 2124 forms a shifted zero order spot 2134 outside of the holographic scene 2132 when viewed by the viewer 2130.

FIG. 22 illustrates an example system 2200 that couples light through a wedge-shaped substrate 2212 of an optical device 2210 to illuminate a display 1610 at an angle of incidence to suppress display zero-order light in a holographic scene. do. Optical device 2210 includes a grating 2214 on a wedge-shaped substrate 2212. Wedge shaped substrate 2212 couples input light 2220 to substrate 2212 which directs input light 2120 towards grating 2214 . Grating 2214 diffracts input light 2120 outward toward display 1610 at an angle of incidence. The hologram is configured such that the diffracted first order light 2222 exits the display 1610 and surrounds normal incidence, forming a reconstruction cone, while the display zero order light 2224 exits the display 1610 at the same angle of reflection as the angle of incidence. Preconfigured. If the angle of incidence is greater than half the viewing angle of the reconstruction cone, the display zero order light 2224 forms a shifted zero order spot 2234 outside of the holographic scene 2232 when viewed by the viewer 2230.

According to a third technique, the display zero order light coming out of the display has a larger deviation angle than the diffracted first order light coming out of the display. Thus, for example, display zero-order light can be suppressed ( or removal).

Fourth Technique - Zero-Order Light Blocking FIGS. 23A-23B illustrate an exemplary method for suppressing display zero-order light in a holographic scene by blocking or absorbing the display zero-order light reflected from the display by an optical blocking component. Examples of systems 2300 and 2350 are illustrated below. The optical blocking component can be any suitable structure, such as a louver layer, a metamaterial layer, a metamaterial structure, a metasurface, or any other type of engineered microstructure or nanostructure that can exhibit blocking properties. It can be.

For purposes of illustration, similar to FIG. 21, a coupling prism 2311 couples collimated input light 2320 to an optical device 2310 having a grating 2314 formed on a substrate 2312. Grating 2314 is configured to diffract input light 2320 outwardly to illuminate display 1610 at an angle of incidence, eg, greater than half the viewing angle of the reconstruction cone. By applying the third technique, the diffracted first order light 2322 emerges from the display 1610 in the same way as the input light enters the display 1610 at normal incidence, while the display zero order light 2324 exits the display 1610 at normal incidence. The hologram is preconfigured to propagate away from the display 1610 with the same reflection angle as the corner.

A metamaterial layer 2316 is formed on (eg, deposited on or attached to) the substrate 2312 as an example of an optical blocking component. As illustrated in FIGS. 23A-23B, metamaterial layer 2316 and lattice 2314 can be formed on both sides of substrate 2312. Metamaterial layer 2316 can be made of an array of microstructures or nanostructures that are smaller than the wavelength of interest. By individually and collectively configuring the microstructure or nanostructure geometry, the metamaterial layer 2316 can be designed to interact with light in a desired manner. In the present disclosure, metamaterial layer 2316 is configured to transmit light beams having angles less than a predetermined angle and block light beams having angles greater than a predetermined angle. The predetermined angle can be set to be less than the angle of incidence and greater than half the viewing angle of the reconstruction cone formed by the diffracted primary light 2322. Thus, the diffracted primary light 2322 is transmitted through the metamaterial layer 2316 with a transmission efficiency, e.g., at least a predetermined percentage, such as 50%, 60%, 70%, 80%, 90%, or 99%. be able to. In contrast, display zero-order light can be blocked or absorbed by metamaterial layer 2316, for example, with 100% blocking efficiency.

The light suppression efficiency of display zero-order light in a holographic scene can be 100%. As illustrated in FIG. 23A, the diffracted first order light 2322 can form a holographic scene 2332 on the projection screen 2330 without display zero order light 2324. As illustrated in FIG. 23B, when viewed by viewer 2360, diffracted first order light 2322 can form a holographic scene 2362 without display zero order light 2324 at the viewer's 2360 eye.

Fifth Technique - Zero-Order Light Redirection FIG. 24 shows a system 2400 for suppressing display zero-order light in a holographic scene by redirecting the display zero-order light away from the holographic scene through an optical redirection structure. Illustrate. The optical redirection structure may be a grating, for example a holographic grating such as a Bragg grating, or any other suitable redirection structure.

Similar to system 590 of FIG. 5H, system 2400 includes a computer 2401 (e.g., computer 591 of FIG. 5H), a controller 2402 (e.g., controller 592 of FIG. 5H), a reflective display 2404 (e.g., the reflective display of FIG. 594), and an illuminator 2406 (eg, illuminator 596 of FIG. 5H). System 2400 also includes an optical diffraction device, such as optical diffraction device 598 of FIG. 5H, 598A of FIG. 5I, 598B of FIG. 5J, or 598C of FIG. 5K, optical diffraction device 900 of FIGS. 1000 of FIG. 11, 1200 of FIG. 12A, 1250 of FIG. 12B, or 1270 of FIG. 12C, or 1500 of FIG. In some implementations, as illustrated in FIG. 24, the optical device 2410 includes a transmission field grating structure 2414 as an optical diffractive device on a substrate 2412 (eg, substrate 598-2 of FIG. 5H). Transmission field grating structure 2414 may be field grating structure 598-1 of FIG. 5H. Transmission field grating structure 2414 can include one or more gratings for one or more different colors of light. Substrate 2412 can be a transparent glass substrate.

Similar to those described above, optical device 2410 can be placed adjacent the front surface of display 2404. In some implementations, the top surface of optical device 2410 (eg, the surface of field grating structure 2414) is attached to the front surface of display 2404, eg, through an index-matching material. In some implementations, an air gap is between the top surface of optical device 2410 and display 2404. In some implementations, a spacer, eg, glass, is inserted into the air gap between the top surface of optical device 2410 and display 2404. To better explain the propagation of light, an air gap is used as an example in FIG. 24 and in FIGS. 26A-33 below.

Controller 2402 receives graphics data corresponding to one or more objects from computer 591 (e.g., by using a 3D software application such as Unity), performs calculations on the graphics data, and performs calculations on the graphics data for modulation. The control signal is configured to be generated and transmitted through memory buffer 2403 to display 2404 . Controller 2402 is also coupled to illuminator 2406 and configured to provide timing signal 2405 to operate illuminator 2406 to provide input light 2420. Input light 2420 is then diffracted by transmission field grating 2414 of optical device 2410 to illuminate display 2404. A first portion of input light 2420 incident on a display element of display 2404 is diffracted by display 2404, and the diffracted primary light 2421 forms a holographic light field 2422 toward the viewer. Holographic light field 2422 can correspond to a reconstruction cone (or truncated cone) with a viewing angle. Display 2404 can include a rearview mirror on the back of display 2404 to reflect light toward the viewer. A second portion of the input light 2420 incident on the gap in the display 2404 is reflected by the display 2404, such as by a rearview mirror, as display zero order light 2424.

As described above, the transmitted field grating 2414 diffracts the input light 2420 outwardly from the illuminator 2406 so that the display 2404 is visible at an angle of incidence, e.g., less than half the viewing angle of the reconstruction cone (or truncated cone). It can be configured to irradiate off-axis at a large angle. By applying the third technique, the diffracted first order light 2421 emerges from the display 2404 in the same manner as when the input light 2420 is incident on the axis at normal incidence, while the display zero order light 2424 It comes out at a reflection angle that is the same as the angle of incidence outside the construction cone.

As illustrated in FIG. 24, the system 2400 provides a system 2400 for diffraction efficiency that is substantially greater than a second light beam having an angle that is different from the predetermined angle, at a diffraction angle that is the same as the predetermined angle. An optical redirection structure 2416 can be included that is configured to diffract the first light beam having a . Optical redirection structure 2416 may be a holographic grating, such as a Bragg grating. The diffraction angle can be substantially larger than the predetermined angle. In some implementations, optical redirection structure 2416 includes one or more gratings for one or more different colors of light, as further illustrated in FIGS. 30A-33. In some implementations, optical redirection structure 2416 is located downstream of optical device 2410, away from display 2404. In some implementations, optical redirection structure 2416 is formed on a side of substrate 2412 that is opposite transmission field grating structure 2414, as illustrated in FIG.

According to a fifth technique, the optical redirection structure 2416 can be configured to have a predetermined angle that is the same as the angle of reflection of the display zero order light 2424 or the angle of incidence of the input light 2420 at the display 2404. When the display zero order light 2424 propagates at the reflected angle, the optical redirection structure 2416 can diffract the display zero order light 2424 at the diffraction angle with substantially greater diffraction efficiency than the diffracted first order light 2421. Meanwhile, the diffracted primary light 2421 can pass through the optical redirection structure 2416 to form a holographic light field 2422. In this manner, optical redirection structure 2416 can redirect display zero order light 2424 further away from holographic light field 2422.

25A-25C illustrate examples of redirecting display zero order light to different directions in space via the zero order redirection gratings 2500, 2530, 2550 of FIGS. 25A, 25B, 25C. Zero order redirection gratings 2500, 2530, 2550 can be within optical redirection grating structure 2416 of FIG. 24. Redirection gratings 2500, 2530, 2550 can be manufactured according to the method illustrated in FIG. 7A.

For comparison, display zero-order light 2502 is incident on zero-order redirection gratings 2500, 2530, 2550 at an angle of incidence of −6.0°, which is a predetermined angle with respect to redirection gratings 2500, 2530, 2550. It is. The redirection gratings 2500, 2530, 2550 are configured to diffract the display zero order light 2502 at a diffraction angle substantially greater than the angle of incidence of the display zero order light 2502 and with high diffraction efficiency. Redirection gratings 2500, 2530, 2550 display zero order light 2502 at different diffraction angles, e.g. 60° for grating 2500 shown in FIG. 25A, 56° for grating 2530 shown in FIG. 25B, and the grating of FIG. 25C. In the case of 2550, it can be configured to diffract at −56°.

26A-26E illustrate examples of redirecting display zero-order light when the light enters different directions in space through an optical redirection structure (e.g., a zero-order redirection grating) at different angles of incidence. Illustrate. Each of the angles of incidence, e.g. -6° or 6° in air, is greater than half the viewing angle of the reconstruction cone corresponding to the holographic light field, e.g. 5° in air. It is configured.

As illustrated in FIG. 26A, system 2600 includes an optical device 2610, which may be optical device 2410 of FIG. 24. Optical device 2610 includes a substrate 2612 (e.g., substrate 2412 of FIG. 24), a transmission field grating structure 2614 (e.g., transmission field grating structure 2414 of FIG. 24), and a zero-order redirection grating structure 2616 (e.g., zero-order redirection grating structure 2616 of FIG. 24). redirection lattice structure 2416). Optical device 2610 can include a cover glass 2618 over zero order redirection grating structure 2616.

Input light 2620 from illuminator 2406 is diffracted by transmission field grating structure 2614 to illuminate display 2404 at an angle of incidence of −6° (in air). A first portion of input light 2620 impinging on a modulated display element of display 2404 is diffracted through optical device 2610 (including zero-order redirection grating structure 2616 ) to create a holographic optical field 2622 . It becomes diffracted primary light 2621. A second portion of the input light 2620 that strikes the gap in the display 2404 is reflected to emerge from the display 2404 as display zero order light 2624. Display zero order light 2624 is redirected by zero order redirection grating structure 2616 at a diffraction angle substantially greater than the angle of incidence, eg -28° in glass. Due to Fresnel reflection, a portion of the redirected display zero-order light is reflected back to optical device 2610 by the interface between cover glass 2618 and air, and the reflected display zero-order light, e.g. The Fresnel reflection of the zero order light 2625 can be absorbed by a light absorber 2619 formed on the edge of the optical device 2610. Light absorber 2619 can be similar to light absorber 1104 in FIG. 11, 1204 in FIGS. 12A, 12C, or 1254 in FIG. 12B. Another portion of the redirected display zero-order light is further away from the holographic light field 2622, at a redirection angle of −45°, e.g., at the redirected zero-order light 2626 through the interface into the air. Transmitted downward.

As illustrated in FIG. 26B, system 2630 includes an optical device 2640, which may be optical device 2410 of FIG. 24. Optical device 2640 includes a substrate 2642 (e.g., substrate 2412 of FIG. 24), a transmission field grating structure 2644 (e.g., transmission field grating structure 2414 of FIG. 24), and a zero-order redirection grating structure 2646 (e.g., zero-order redirection grating structure 2646 of FIG. 24). redirection lattice structure 2416). Optical device 2640 can include a cover glass 2648 over zero order redirection grating structure 2646.

Unlike the transmitted field grating structure 2614 of the optical device 2610 of FIG. 26A, the transmitted field grating structure 2644 of the optical device 2640 diffracts the input light 2620 from the illuminator 2406 to the display 2404 at an incident angle of +6° (in air). irradiate. A first portion of input light 2620 impinging on a modulated display element of display 2404 is diffracted through optical device 2640 (including zero-order redirection grating structure 2646) to create a holographic optical field 2632. It becomes a diffracted primary light 2631. A second portion of the input light 2620 that strikes the gap in the display 2404 is reflected to emerge from the display 2404 as display zero order light 2634. Unlike the zero-order redirection grating structure 2616 of FIG. 26A, the zero-order redirection grating structure 2646 redirects the display zero-order light 2624 at a diffraction angle substantially greater than the angle of incidence, e.g., +28° in glass (or diffraction). Due to Fresnel reflection, a portion of the redirected display zero-order light is reflected back to optical device 2610 by the interface between cover glass 2618 and air, and the reflected display zero-order light, e.g. The Fresnel reflection of the zero order light 2635 can be absorbed by a light absorber 2649 formed on the edge of the optical device 2640. Light absorber 2649 may be similar to light absorber 2619 of FIG. 26A. Another portion of the redirected display zero-order light is further away from the holographic light field 2622, at a redirection angle of +45°, e.g., at the redirected zero-order light 2636 through the interface into the air. Transmitted upwards.

As illustrated in FIG. 26C, system 2650 includes an optical device 2660, which can be optical device 2410 of FIG. 24. Optical device 2660 includes a substrate 2662 (e.g., substrate 2412 of FIG. 24), a transmitted field grating structure 2664 (e.g., transmitted field grating structure 2414 of FIG. 24), and a zero-order redirection grating structure 2666 (e.g., zero-order redirection grating structure 2666 of FIG. 24). redirection lattice structure 2416). Optical device 2660 can include a cover glass 2668 over zero order redirection grating structure 2666.

Similar to the transmitted field grating structure 2614 of the optical device 2610 of FIG. 26A, the transmitted field grating structure 2664 of the optical device 2660 diffracts the input light 2620 from the illuminator 2406 for display at an angle of incidence of −6° (in air). Irradiate 2404. A first portion of input light 2620 impinging on a modulated display element of display 2404 is diffracted through optical device 2660 (including zero-order redirection grating structure 2666 ) to create a holographic optical field 2632 . It becomes a diffracted primary light 2631. A second portion of the input light 2620 that strikes the gap in the display 2404 is reflected out of the display 2404 and becomes at least a portion of the display zero order light 2654. Unlike the zero-order redirection grating structure 2616 of FIG. 26A, the zero-order redirection grating structure 2666 redirects the display zero-order light 2654 at a diffraction angle substantially greater than the angle of incidence, e.g., +28° in glass (or diffraction). Due to Fresnel reflection, a portion of the redirected display zero-order light is reflected back to optical device 2660 by the interface between cover glass 2668 and air, and the reflected display zero-order light, e.g. Fresnel reflections of zero order light 2655 can be absorbed by light absorbers 2649 formed on the edges of optical device 2640. Light absorber 2669 can be light absorber 2619 of FIG. 26A. Another portion of the redirected display zero-order light is further away from the holographic light field 2622, at a redirection angle of +45°, e.g., at the redirected zero-order light 2656 through the interface into the air. Transmitted upwards.

An anti-reflection (AR) coating can be formed on the surface of the cover glass 2668 to eliminate the effects of Fresnel reflections on the redirected display zero-order light on the interface between the cover glass surface and the air. , thus the redirected display zero-order light can be transmitted into the air with high transmission, but with little or no reflection back to the optical device.

As illustrated in FIG. 26D, system 2670 includes an optical device 2680. Similar to optical device 2660 of FIG. 26C, optical device 2680 diffracts input light 2620 to illuminate display 2404 at an angle of incidence of −6° (in air) and directs display zero-order light 2654 to a redirection angle of +45°. is configured to redirect upward into the air. However, unlike the optical device 2660 of FIG. 26C, the optical device 2680 includes an AR coating layer 2682 formed on the outer surface of the cover glass 2668, and thus the redirected display zero-order light is displayed at a redirection angle of +45°. For example, the redirected zero order light 2672 is transmitted through the cover glass 2668 and substantially into the air. In such a manner, there is little or no Fresnel reflection of the zero order light that is redirected back to optical device 2680.

FIG. 26E shows another example of redirecting display zero order light at a larger redirection angle, for example, +75° in air, or about +40° in glass. As illustrated in FIG. 26E, system 2690 includes an optical device 2692. Similar to optical device 2660 of FIG. 26C, optical device 2692 is configured to diffract input light 2620 to illuminate display 2404 at an angle of incidence of −6° (in air). However, unlike optical device 2660 of FIG. 26C, optical device 2692 is configured to redirect zero-order light 2654 upward into air at a redirection angle of +75°, e.g., to redirected zero-order light 2696. includes a zero-order redirection lattice structure 2694 . Therefore, there is a larger Fresnel reflection of zero order light 2698 back into optical device 2692, which can be absorbed by light absorber 2669.

When light with p-polarization is incident at the Brewster angle at the interface between a larger and a smaller refractive index medium, there is no Fresnel reflection for light with p-polarization.

FIG. 27A illustrates an example system 2700 that redirects display zero order light with p-polarization to transmit into air at Brewster's angle. System 2700 includes an optical device 2710, which may be optical device 2410 of FIG. Optical device 2710 includes a substrate 2712 (e.g., substrate 2412 of FIG. 24), a transmitted field grating structure 2714 (e.g., transmitted field grating structure 2414 of FIG. 24), and a zero-order redirection grating structure 2716 (e.g., zero-order redirection grating structure 2716 of FIG. 24). redirection lattice structure 2416). Optical device 2710 can include a cover glass 2718 over zero order redirection grating structure 2716.

Similar to the transmitted field grating structure 2614 of the optical device 2610 of FIG. 26A, the transmitted field grating structure 2714 of the optical device 2710 diffracts the input light 2620 from the illuminator 2406 for display at an angle of incidence of −6° (in air). Irradiate 2404. A first portion of input light 2620 impinging on a modulated display element of display 2404 is diffracted through optical device 2710 (including zero-order redirection grating structure 2716) to create holographic light field 2702. It becomes diffracted primary light 2701. A second portion of input light 2620 that strikes the gap in display 2404 is reflected to emerge from display 2404 as display zero order light 2704 . Display zero order light 2704 can have a p polarization state. In some cases, input light 2620 from illuminator 2406 has a p-polarization state. In some cases, optical device 2710 includes one or more optical polarizing devices (e.g., polarizers, retarders, wavelength board, or a combination thereof). In some implementations, optical device 2710 includes an optical retarder (eg, a broadband half-wave retarder) followed by an optical polarizer (eg, a linear polarizer). The optical retarder is configured, for example, to rotate each color of light from s-polarization to p-polarization with corresponding efficiency, and the optical polarizer rotates any proportion of each color that is not rotated from s-polarization to p-polarization. constructed to absorb light.

Unlike the zero-order redirection grating structure 2616 of FIG. 26A, the zero-order redirection grating structure 2716 displays the zero-order Redirect (or diffract) light 2654. Therefore, there is no Fresnel reflection of the redirected display zero order light back to the optical device 2710, and substantially all of the redirected display zero order light is at a Brewster angle of approximately -57°, e.g. It is permeated into the air at 2706.

27B-27C illustrate an example of redirecting display zero order light with s-polarization using an optical polarization device, such as an optical retarder, for transmission at Brewster's angle. If the display zero-order light exits the display 2404 with s-polarization, the optical device can include an optical retarder before the interface to air. The optical retarder can convert the polarization state of the display zero-order light from an s-polarization state to a p-polarization state for transmission at the Brewster angle at the air interface without Fresnel reflection.

As illustrated in FIG. 27B, system 2730 includes an optical device 2740, which can be optical device 2410 of FIG. 24. Optical device 2740 includes a substrate 2742 (e.g., substrate 2412 of FIG. 24), a transmitted field grating structure 2744 (e.g., transmitted field grating structure 2414 of FIG. 24), and a zero-order redirection grating structure 2746 (e.g., zero-order redirection grating structure 2746 of FIG. 24). redirection lattice structure 2416). Optical device 2740 can include a cover glass 2748 over zero order redirection grating structure 2746.

Similar to the transmitted field grating structure 2714 of the optical device 2710 of FIG. 27A, the transmitted field grating structure 2744 of the optical device 2740 diffracts the input light 2620 from the illuminator 2406 for display at an angle of incidence of −6° (in air). Irradiate 2404. A first portion of input light 2620 impinging on a modulated display element of display 2404 is diffracted through optical device 2740 (including zero-order redirection grating structure 2746) to create a holographic optical field 2732. It becomes a diffracted primary light 2731. A second portion of input light 2620 that strikes the gap in display 2404 is reflected to emerge from display 2404 as display zero order light 2734. Unlike display zero order light 2704 of FIG. 27A, display zero order light 2734 can have s-polarization. In some cases, input light 2620 from illuminator 2406 has an s polarization state. In some cases, optical device 2740 includes one or more optical polarization devices configured to control the polarization state of diffracted input light 2620 to be s-polarized.

Unlike optical device 2710 of FIG. 27A, optical device 2740 includes an optical retarder 2747 that is configured to convert the polarization state of display zero order light 2734 from s-polarization to p-polarization. In some examples, polarization conversion can be accomplished using a broadband half-wave retarder that can rotate each color of light from s-polarization to p-polarization with different efficiencies for each color. The half-wave retarder is followed by a "clean-up" linear polarizer to absorb the proportion of each color's light that has not been rotated from s-polarization to p-polarization. In this way, the retarder can rotate the polarization of the light emerging from the optical device 2740 to another polarization more suitable for best performance of the display 2404, and the linear polarizer can rotate the polarization of the light emerging from the optical device 2740 to another polarization more suitable for the best performance of the display 240. Light incident on display 2404 that is not polarized can be filtered out.

In some implementations, as illustrated in FIG. 27B, an optical retarder 2747 (and optionally a linear polarizer) is placed in front of the zero order redirection grating structure 2746 on the substrate 2742. . Similar to zero-order redirection grating structure 2716 of FIG. 27A, zero-order redirection grating structure 2746 directs p-polarized light at the interface between cover glass 2748 and air at Brewster's angle, e.g., approximately -37° within the glass. Display zero-order light 2734 with redirection (or diffraction). Therefore, there is no or negligible Fresnel reflection of the redirected display zero-order light back to the optical device 2740, and nearly all of the redirected display zero-order light is at a Brewster angle of approximately -57°. For example, the redirected zero order light 2736 is transmitted into the air.

In some implementations, as illustrated in FIG. 27C, in optical device 2760 of system 2750, optical retarder 2747 is positioned after zero-order redirection grating structure 2746 with respect to substrate 2742. A zero order redirection grating structure 2746 is disposed between the substrate 2742 and a grating cover glass 2748. Optical retarder 2747 can be placed between grating cover glass 2748 and retarder cover glass 2762. Similar to zero-order redirection grating structure 2716 of FIG. 27A, zero-order redirection grating structure 2746 displays zero-order at the interface between cover glass 2762 and air at Brewster's angle, e.g. Redirect (or diffract) light 2734. Therefore, there is no or negligible Fresnel reflection of the redirected display zero-order light back to the optical device 2760, and nearly all of the redirected display zero-order light is at a Brewster angle of about -57°, e.g. , the redirected zero-order light 2752 is transmitted into the air.

FIG. 28 shows an example system 2800 that redirects display zero order light to an anisotropic transmitter 2820 to absorb the redirected display zero order light. The anisotropic transmitter 2820 transmits the first light beam (e.g., the diffracted primary light) at an angle less than the predetermined angle (e.g., less than half the viewing angle of the reconstruction cone), and The second light beam (e.g., the redirected display zero-order light) is configured to absorb the second light beam (e.g., the redirected display zero-order light) at an angle (e.g., the redirection angle) that is greater than the redirection angle. The predetermined angle is configured to be greater than half the viewing angle and less than a redirection angle at which display zero order light is diffracted by the optical redirection component.

System 2800 includes an optical device 2810, which can include optical device 2410 of FIG. Optical device 2810 includes a substrate 2812 (e.g., substrate 2412 of FIG. 24), a transmitted field grating structure 2814 (e.g., transmitted field grating structure 2414 of FIG. 24), and a zero-order redirection grating structure 2816 (e.g., zero-order redirection grating structure 2816 of FIG. 24). redirection lattice structure 2416). Optical device 2810 can include a cover glass 2818 over zero order redirection grating structure 2816.

Similar to the transmission field grating structure 2414 of the optical device 2410 of FIG. Irradiate 2404. A first portion of input light 2620 impinging on a modulated display element of display 2404 is diffracted through optical device 2810 (including zero-order redirection grating structure 2816) to create holographic light field 2802. It becomes a diffracted primary light 2801. The angle of incidence is configured to be greater than half the viewing angle of the reconstruction cone corresponding to the holographic light field 2802. A second portion of the input light 2620 that is illuminated onto the gap in the display 2404 is reflected out of the display 2404 as at least a portion of the display zero order light 2804. Similar to zero-order redirection grating structure 2416 of FIG. 24, zero-order redirection grating structure 2816 can display zero-order Redirect (or diffract) light 2804.

Unlike the optical diffractive structure 2410 of FIG. 24, the optical device 2810 can include an anisotropic transmitter 2820 configured to transmit the diffracted first order light 2801 and absorb the display zero order light 2804. . In some examples, anisotropic transmitter 2820 includes a louvered film configured to have about ±30° in air or about ±20° in acrylic. Anisotropic transmitter 2820 substantially transmits diffracted first-order light 2801, e.g., at about ±5° in air (about ±3° in acrylic), and transmits display zero-order light 2804, e.g. Absorbs in air at approximately 75°. The anisotropic transmitter 2820 is arranged such that there is no significant Fresnel reflection from the surface of the anisotropic transmitter 2820 back to the optical device 2810 for display zero-order light 2804 having either an s-polarization state or a p-polarization state. The index can be matched to the cover glass 2818. The louvers in the louver film can also be index matched to the transparent material of the louver film to eliminate Fresnel reflections from the louvers.

In the previous example shown in Figures 26A-26E, 27A-27B, and Figure 28, the zero-order redirection grating structure displays zero-order light at a redirection angle that is less than the critical angle for total internal reflection at the air-to-air interface. It is configured to cause diffraction.

FIG. 29 illustrates an example system 2900 that redirects display zero order light to fully reflect the display zero order light. Similar to optical device 2610 of FIG. 26A, optical device 2910 of system 2900 is formed on substrate 2912 and diffracts input light 2620 at an angle of incidence of -6° in air and in glass. Includes a transmitted field grating structure 2914 configured to illuminate display 2404 at approximately −4°.

However, unlike optical device 2610 of FIG. 26A, optical device 2910 has a critical angle for total internal reflection in the glass for the transition from cover glass 2918 to air at high-low index interface 2919, e.g. A zero order redirection grating structure 2916 configured to redirect display zero order light 2904 at a redirection angle in the glass greater than about 41 degrees, eg, about +60 degrees. Thus, the display zero order light 2904 is completely reflected at the interface 2919, and the Fresnel reflection of the display zero order light 2906 is reflected by the light absorber 2920 formed at the edge of the optical device 2910 (e.g., the light absorber of FIG. 26A). 2619). In contrast, a portion of input light 2620 that impinges on a modulated display element of display 2404 is diffracted through optical device 2910 (including zero-order redirection grating structure 2916) to transmit display zero-order light 2904. The result is a diffracted first order light 2901 forming a holographic light field 2902 without any rays.

The input light that illuminates the display can include a plurality of different colors of light, such as red, green, and blue, for example. Light of different colors can be sequentially incident on the display, and corresponding holographic data (or holograms) of different colors can sequentially modulate the display elements of the display. As described above, an optical diffraction device, such as optical diffraction device 598 of FIG. 5H, can be configured to diffract different colors of light to illuminate the display and also It can also be configured to reduce color crosstalk. For example, optical diffraction device 598 includes multiple holographic gratings for different colors in different recording layers, as illustrated in FIGS. 9A-12C, for example. In some examples, the optical diffractive device includes one or more color selections to suppress (e.g., eliminate or minimize) color crosstalk, as described above with respect to FIGS. 9A-10B. A plurality of holographic gratings with polarizers can be included. In some examples, as described above with respect to FIGS. 11-12C and 15, the optical diffraction device may be configured for different colors of light incident at respective angles of incidence to suppress color crosstalk and zero-order light. A plurality of holographic gratings having one or more reflective layers can be included.

Similarly, the optical redirection device can also be configured to redirect display zero-order light of a different color out of the corresponding holographic scene, and also for example to redirect the holographic in-plane and/or in-space It may also be configured to reduce color crosstalk between display zero order light of different colors by redirecting the display zero order light of different colors in different directions away from the scene. Below, FIGS. 30A-30B, 31A-31B, 32, and 33 illustrate different examples of implementations.

30A-30B illustrate an example of redirecting display zero order light of two different colors (eg, blue and red) in different directions away from the holographic scene.

As illustrated in FIG. 30A, similar to system 2400 of FIG. 24, system 3000 includes a computer 2401 (e.g., computer 2401 of FIG. 24), a controller 3002 (e.g., controller 2402 of FIG. 24), a reflective display 3004 (eg, reflective display 2404 of FIG. 24), and an illuminator 3006 (eg, illuminator 2406 of FIG. 24). System 3000 also includes an optical diffractive device 3010, which can include an optical diffractive device, such as optical diffractive device 900 of FIGS. 9A and 9B, or 1100 of FIG. 11. In some implementations, as illustrated in FIG. 30A, optical device 3010 includes a transmitted field grating structure 3014 on a substrate 3012 (eg, substrate 2412 of FIG. 24). Transmission field grating structure 3014 may include two corresponding different gratings for two different colors of light.

Controller 3002 receives graphics data corresponding to one or more objects from computer 3001 (e.g., by using a 3D software application such as Unity), performs calculations on the graphics data, and performs calculations on the graphics data for modulation. The control signal is configured to be generated and transmitted through memory buffer 3003 to display 3004 . Controller 3002 is also coupled to illuminator 3006 and configured to provide a timing signal 3005 to operate illuminator 3006 to provide input light 3020. Input light 3020 is then diffracted by transmission field grating structure 3014 of optical device 3010 to illuminate display 3004. A first portion of input light 3020 incident on a display element of display 3004 is diffracted by display 3004, and the diffracted primary light 3021 forms a holographic light field 3022 towards the viewer. The holographic light field 3022 can correspond to a reconstruction cone (or truncated cone) with a viewing angle. A second portion of the input light 3020 incident on the gap in the display 3004 is reflected by the display 3004 and becomes at least a portion of the display zero order light 3024.

Transmission field grating structure 3014 diffracts input light 3020 of different colors outward from illuminator 3006 to display display 3004 at an angle of incidence greater than half the viewing angle of the reconstruction cone (or truncated cone), e.g. , configured to illuminate off-axis at -6° in air or about -4° in glass. By applying the third technique, the diffracted first order light 3021 emerges from the display 3004 in the same manner as when the input light 3020 is incident on the axis at normal incidence, while the display zero order light 3024 It comes out at a reflection angle that is the same as the angle of incidence outside the construction cone.

As illustrated in FIG. 30A, the system 3000 can include an optical redirection structure with corresponding zero order redirection gratings 3016 and 3018 for different colors of light (blue and red). Each zero order redirection grating 3016, 3018 may be similar to redirection grating 2416 of FIG. , may be configured to diffract a first light beam having an angle that is the same as the predetermined angle. Each zero order redirection grating 3016, 3018 may be a holographic grating, such as a Bragg grating for a corresponding color of light.

As illustrated in FIG. 30A, the zero order redirection grating 3016 redirects the blue display zero order light at a diffraction angle of +45° in air (approximately +28° in glass), e.g. It is configured to diffract the secondary light 3026 at the reflection angle (same as the incident angle). The zero order redirection grating 3018 redirects the red display zero order light from about -6° in air (about -4° in glass) to about -45° (about -28° in glass), e.g. The display is configured to diffract zero order light 3028.

Zero order redirection gratings 3016, 3018 may be sequentially disposed on substrate 3012 opposite transmission field grating structure 3014. Since light with shorter wavelengths tends to crosstalk more strongly from gratings intended for longer wavelengths, the zero-order redirection grating 3016 for blue light is similar to the zero-order redirection grating 3016 for red light. It can be placed closer to the display than 3018. The two zero order redirection gratings 3016, 3018 can have substantially different fringe plane slopes, which can reduce chromatic crosstalk.

In some implementations, as illustrated in FIG. 30A, each zero-order redirection grating 3016, 3018 for a different color of light is recorded in a corresponding recording material, e.g., a photopolymer, with a corresponding It is protected by cover glasses 3017 and 3019.

In some implementations, as illustrated in FIG. 30B, each zero-order redirection grating 3046, 3048 of the optical device 3040 in the system 3030 for different colors of light is made of the same recording material, e.g. Recorded in polymer and protected by cover glass 3047. The zero order redirection grating 3046 can be the same as the zero order redirection grating 3016 and redirects the blue display zero order light from about -6° in air (about -4° in glass) to about +45° (about +45° in glass). +28°), for example, is configured to diffract into the redirected blue display zero order light 3036. The zero order redirection grating 3048 may be the same as the zero order redirection grating 3018 and may redirect the red display zero order light from about -6° in air (about -4° in glass) to about -45° (in glass). (approximately −28°), for example, is configured to diffract into the redirected red display zero order light 3038.

Optical devices 3010, 3040 include light absorbers (e.g., light absorber 2619 in FIG. 26A) on the edges of optical devices 3010, 3040 to reduce Fresnel reflections at the interface between the cover glass and air. can be included.

31A-31B illustrate example systems 3100 and 3150 that redirect display zero-order light of three different colors (blue, green, red) in different directions away from a holographic scene in the same plane. . Compared to a system for two different colors of light, a system for three different colors of light, as illustrated in FIGS. 30A or 30B, for example, diffracts input light of three colors. an optical diffraction structure containing three different diffraction gratings to illuminate the display at the same angle of incidence and three different zeros to diffract the display zero-order light of three colors at different diffraction angles toward different directions. an optical redirection structure including a second redirection grating.

As illustrated in FIG. 31A, similar to system 3000 of FIG. 30A, system 3100 includes a computer 3101 (e.g., computer 3101 of FIG. 30A), a controller 3102 (e.g., controller 3002 of FIG. 30A), a reflective display 3104 (e.g., reflective display 3004 of FIG. 30A), and an illuminator 3106 (e.g., illuminator 3006 of FIG. 30A). System 3100 may also include an optical diffractive device, such as optical diffractive device 1000 of FIGS. 10A and 10B, 1200 of FIG. 12A, 1250 of FIG. 12B, or 1270 of FIG. 12C, or optical device 3110 of FIG. 15. Also included. In some implementations, as illustrated in FIG. 31A, optical device 3110 includes a transmitted field grating structure 3112 on a substrate 3111. Transmission field grating structure 3112 may include three corresponding different gratings for three different colors of light.

Controller 3102 receives graphics data corresponding to one or more objects from computer 3101 (e.g., by using a 3D software application such as Unity), performs calculations on the graphics data, and performs calculations on the graphics data for modulation. The control signal is configured to be generated and transmitted through memory buffer 3103 to display 3104 . Controller 3102 is also coupled to illuminator 3106 and configured to provide timing signal 3105 to operate illuminator 3106 to provide input light 3120. Input light 3120 is then diffracted by transmission field grating 3112 of optical device 3110 to illuminate display 3104. A first portion of input light 3120 incident on a display element of display 3104 is diffracted by display 3104, and the diffracted primary light 3121 forms a holographic light field 3122 towards the viewer. The holographic light field 3122 can correspond to a reconstruction cone (or truncated cone) with a viewing angle. A second portion of input light 3120 incident on the gap in display 3104 is reflected by display 3104 and becomes display zero order light 3123.

Transmission field grating 3112 diffracts input light 3120 of different colors outward from illuminator 3106 to display display 3104 at an angle of incidence greater than half the viewing angle of the reconstruction cone (or truncated cone), e.g. It is configured to illuminate off-axis at -6° in air or about -4° in glass. By applying the third technique, the diffracted first order light 3121 emerges from the display 3104 in the same manner as when the input light 3120 is incident on the axis at normal incidence, while the display zero order light 3123 It comes out at a reflection angle that is the same as the angle of incidence outside the construction cone.

As illustrated in FIG. 31A, system 3100 includes an optical redirection structure with three corresponding zero-order redirection gratings 3114, 3116, and 3018 for light of different colors (blue, green, and red). be able to. Each zero order redirection grid 3114, 3116, 3118 may be similar to redirection grid 2416 of FIG. 24. Each zero order redirection grating 3114, 3116, 3118 may be a holographic grating, such as a Bragg grating for a corresponding color of light.

Zero-order redirection gratings 3114 , 3116 , 3118 may be sequentially disposed on substrate 3111 opposite transmission field grating structure 3112 . In some implementations, as illustrated in FIG. 31A, each zero-order redirection grating 3114, 3116, 3118 for a different color of light (blue, green, red) has a corresponding recording material, e.g. Recorded in a photosensitive polymer and protected by corresponding cover glasses 3113, 3115, 3117. As mentioned above, the zero-order redirection gratings 3114, 3116, 3118 for three different colors of light can be recorded in the same recording material, for example a photopolymer, and protected by a cover glass. The three zero order redirection gratings 3114, 3116, 3118 can have substantially different fringe plane slopes, which can reduce chromatic crosstalk.

As illustrated in FIG. 31A, the blue zero-order redirection grating 3114 redirects the blue display zero-order light from about -6° in air (about -4° in glass) to about +45° (about +45° in glass). +28°), for example, is configured to diffract the redirected blue display zero order light 3124. The green zero order redirection grating 3116 redirects the green display zero order light from about -6° in air (about -4° in glass) to about -45° (about -28° in glass), for example. The green display is configured to diffract zero-order light 3126. The red zero order redirection grating 3118 redirects the red display zero order light from approximately -6° in air (approximately -4° in glass) to approximately -57° at the Brewster angle (approximately -37° in glass). For example, the redirected red display is configured to diffract zero order light 3128 . If the red display zero-order light has a p-polarization state, the red display zero-order light can be completely transmitted into the air. Optical device 3110 includes one or more light absorbers on one or more edges of optical device 3110 to reduce Fresnel reflections of blue and green display zero-order light at the interface between the cover glass and air. (eg, light absorber 2619 in FIG. 26A).

If all three colors of display zero-order light have a p-polarization state, e.g. when the input light is p-polarized, the optical redirection device displays all three different colors of display zero-order light at Brewster's angle. The display can include a zero-order redirection grating for the display zero-order light of three different colors, configured to be diffracted into the air at an angle, which can reduce Fresnel reflections. One or more diffraction gratings can be used together to redirect light of a particular color.

As illustrated in FIG. 31B, the optical device 3160 of the system 3150 includes a blue redirection grating 3164, a pair of green redirection gratings 3166-1, 3166-2, and a red redirection grating 3168, which have corresponding recording The information is recorded on the medium and protected by corresponding cover glasses 3163, 3165-1, 3165-2, and 3167. The blue zero-order redirection grating 3164 redirects the blue display zero-order light from approximately +6° in air (approximately +4° in glass) to approximately -57° in air at the Brewster angle (approximately -37° in glass). For example, the redirected red display is configured to diffract zero order light 3154. The green display zero order light is first diffracted by the first green zero order redirection grating 3166-1 from about +6° in air (about +4° in glass) to about +70° (about +38° in glass). and then by a second green zero-order redirection grating 3166-2 to a Brewster angle of about -57° in air (about -37° in glass), e.g., to a redirected green display zero-order light 3156. It is diffracted. Red zero-order redirection grating 3168 redirects red display zero-order light from about +6° in air (about +4° in glass) to about +57° Brewster angle (about +37° in glass), e.g. The red display is configured to diffract the zero order light 3158. The four zero order redirection gratings 3164, 3166-1, 3166-2, and 3168 can have substantially different fringe plane slopes, which can reduce chromatic crosstalk.

To reduce color crosstalk between display zero-order light of different colors, the optical redirection device directs display zero-order light of different colors to It can be configured to redirect to different directions within the sample plane. The optical redirection device can also be configured to redirect display zero order light of different colors toward different planes in space, as illustrated in FIG. 32.

FIG. 32 shows an example system 3200 that includes an optical device 3210 that redirects display zero-order light of three different colors (e.g., blue, green, and red) in different directions away from the corresponding holographic scene in space. Illustrate.

Similar to optical device 3110 of FIG. 31A, optical device 3210 includes a transmission field grating structure 3212, which is the same as transmission field grating structure 3112 of FIG. ) is configured to illuminate the display 3104 off-axis at an angle of incidence that is greater than half the viewing angle of the display 3104, eg, −6° in air or approximately −4° in glass. By applying the third technique, the diffracted primary light emerges from the display 3104 in the same manner as when the input light is incident on the axis at normal incidence. As mentioned above, light with a larger wavelength corresponds to a larger viewing angle. As illustrated in FIG. 32, the blue diffracted primary light forms a blue holographic light field 3220, the green diffracted primary light forms a green holographic light field 3222, and the red diffracted primary light forms a green holographic light field 3222. The diffracted primary light forms a red holographic light field 3224.

Similar to the optical device 3110 of FIG. 31A, the optical device 3210 includes a blue redirection grating 3214, a green redirection grating recorded on different recording media and sequentially arranged on opposite sides of the substrate 3211 with respect to the transmitted field grating structure 3212. 3216 , including a red redirection grid 3218 . Blue redirection grid 3214, green redirection grid 3216, and red redirection grid 3218 are protected by corresponding blue, green, and red cover glasses 3213, 3215, 3217. However, unlike the redirection gratings 3114, 3116, 3118 of FIG. 31A, the redirection gratings 3214, 3216, 3218 redirect the display zero order light of the corresponding color to a different plane.

For example, as illustrated in FIG. 32, the blue redirection grating 3214 redirects the blue display zero-order light from about -6° in air (about -4° in glass) to about +57° in air ( 3230 into the redirected blue zero-order light 3230. The red redirection grating 3218 redirects the red display zero-order light from approximately -6° in air (approximately -4° in glass) to approximately -57° in air (approximately -37° in glass) downward. Brewster's angle, eg, redirect downward redirected red zeroth order light 3234. The green redirection grating 3216 redirects the green display zero order light from approximately -6° in air (approximately -4° in glass) to the rightward Brewster angle (approximately +57° in air and approximately +37° in glass). °), e.g., redirect to the right a redirected green zero-order light 3232 perpendicular to the plane of the upward redirected blue zero-order light 3230 and the downward redirected red zero-order light 3234. Note that the blue 3214 and red redirection gratings 3218 have different fringe plane tilts and/or orientations than the green redirection grating 3216, which can suppress color crosstalk.

FIG. 33 shows another illustration of redirecting three different colors of display zero-order light in different directions from a holographic scene using at least one switchable grating for at least one corresponding color display zero-order light. An exemplary system 3300 is illustrated.

Similar to the optical device 3110 of FIG. 31A, the optical device 3310 in the system 3300 includes a blue redirection grating 3314, a green redirection grating 3316, and a red redirection grating sequentially disposed on opposite sides of the substrate 3111 with respect to the transmitted field grating structure 3112. Contains 3318. The blue, green, red redirection gratings 3314, 3316, 3318 are protected by corresponding blue, green, red cover glasses 3313, 3315, 3317. Similar to the blue 3114 and red redirection gratings 3118 of FIG. 31A, the blue 3314 and red redirection gratings 3318 are permanently recorded on the corresponding recording media.

However, unlike the green redirection grating 3116 of FIG. 31A, which is permanently recorded on a corresponding recording medium, the green redirection grating 3316 is made of a switchable recording material, such as an electrically switchable holographic polymer dispersed It is recorded in a liquid crystal (HPDLC) material and configured to be switchable between different states. For example, the green redirection grating 3316 can be switched to a first state during a first interval of a field continuous color (FSC) illumination sequence when only green light is present. During the first green-only interval, the switchable green redirection grating 3316 in the first state changes the green display zero-order light from about -6° in air (about -4° in glass) to The redirected green display zero order light 3338 is diffracted at a downward angle of about -45° (about -28° in glass), for example.

During other intervals of the FSC color illumination sequence, when only red or blue light is present, the switchable green redirection grating 3316 is in a second state in which the switchable green redirection grating does not diffract red or blue light. can be switched to As illustrated in FIG. 32, the blue redirection grating 3314 redirects the blue display zero-order light from about -6° in air (about -4° in glass) to about +45° in air (about -4° in glass). 3336) into an upwardly redirected blue zero-order light 3336, e.g. The red redirection grating 3318 redirects the red display zero-order light from approximately -6° in air (approximately -4° in glass) to approximately -45° in air (approximately -28° in glass) downward. Angle, eg, downward redirected red zero order light 3340. The redirected red zero-order light 3340 has the same direction as the redirected green zero-order light 3338, but the switchable green redirection grating 3316 has a first spacing for redirecting the green light. or a first state between the parts or parts and a second state between all, part, or parts of the other interval for transmitting red light or blue light; This can suppress color crosstalk.

In some implementations, two or more separate switchable grids can be used for two or more corresponding colors with fewer or no permanently recorded grids, and this can further suppress color crosstalk. In some implementations, the binary (on/off) switchable grating is a switchable grating in which a first switching state diffracts a first color and a second switching state diffracts a second color. , which may allow less or no use of permanently recorded grids.

FIG. 34 is a flowchart of an example process 3400 for suppressing display zero order light in a holographic scene. Process 3400 can be implemented in a system for reconstructing 2D or 3D objects. The system may be any suitable system, such as system 500 of FIG. 5A, 520 of FIG. 5B, 530 of FIG. 5C, 540 of FIG. 5D, 560 of FIG. 5E, 570 of FIG. 590, 590A in FIG. 5I, 590B in FIG. 5J, 590C in FIG. 5K, 1800 in FIG. 18, 1950 in FIG. 19B, 1980 in FIG. 19C, 2100 in FIG. 2350, 2400 in FIG. 24, 2600 in FIG. 26A, 2630 in FIG. 26B, 2650 in FIG. 26C, 2670 in FIG. 26D, 2690 in FIG. 26E, 2700 in FIG. 27A, 2730 in FIG. 2900 in FIG. 29, 3000 in FIG. 30A, 3030 in FIG. 30B, 3100 in FIG. 31A, 3150 in FIG. 31B, 3200 in FIG. 32, or 3300 in FIG.

At 3402, the display is illuminated with light. A first portion of the light illuminates a display element of the display. In some cases, the second portion of light illuminates the gap between adjacent display elements. The display may be display 1610 of FIG. 16, the display element may be display element 1612 of FIG. 16, and the gap may be gap 1614 of FIG. 16.

At 3404, a display element of the display is modulated with a hologram corresponding to the holographic data to diffract a first portion of the light to form a holographic scene corresponding to the holographic data, and display in the holographic scene. Suppresses zero-order light. Display zero order light may include reflected light from the display, eg, a second portion of light reflected at a gap. The reflected light from the display may be the dominant order of the display zero order light. Display zero-order light also includes any unwanted or undesired light, such as diffracted light in the gap, reflected light at the surface of the display element, and reflected light at the surface of the display cover that covers the display. be able to. The holographic scene corresponds to a reconstruction cone (or truncated cone) with a viewing angle. The hologram is configured such that display zero order light is suppressed in the holographic scene. The hologram may be configured such that the diffracted first portion of light has at least one property different from the display zero order light. The at least one characteristic may include power density (e.g., as illustrated in FIG. 18), beam divergence (e.g., as illustrated in FIG. 18), direction of propagation away from the display (e.g., as illustrated in FIG. 19B, 19C, 20B, and 21-33) or polarization states.

Display zero-order light is suppressed with light suppression efficiency in the holographic scene. Light suppression efficiency shall be defined as 1 minus the ratio of the amount of display zero-order light in a holographic scene with suppression to the amount of display zero-order light in a holographic scene without any suppression. Can be done. In some examples, the light suppression efficiency exceeds a predetermined percentage that is one of 50%, 60%, 70%, 80%, 90%, or 99%. In some examples, the light suppression efficiency is 100%.

In some implementations, the process 3400 calculates, for each of the plurality of primitives corresponding to the object, the electromagnetic (EM) field propagation from the primitive to the display element in a global three-dimensional (3D) coordinate system. The method further includes determining an EM field contribution to each of the display elements of the display, and generating, for each of the display elements, a sum of EM field contributions from the plurality of primitives to the display element. The holographic data may include the sum of EM field contributions from multiple primitives of the object to display elements of the display. If the display is phase modulated, the holographic data may include the respective phases for the display elements of the display. The holographic scene may include reconstructed objects corresponding to the objects. Holographic data can include information for more than one object.

In some implementations, as discussed above with respect to the first technique, “phase calibration,” the hologram adjusts the respective phases for the display elements within a predetermined phase range, e.g., [0,2π] It can be configured by adjusting it so that it has. In some implementations, each phase has the following equation (15):
can be adjusted according to
During the ceremony,
represents the initial phase value of each phase,
represents the adjusted phase value of each phase, and A and B are constants of each phase. Constants A and B are such that the light suppression efficiency of the holographic scene is maximized or exceeds a predetermined threshold, e.g., 50%, 60%, 70%, 80%, 90%, or 99%. Can be adjusted. In some implementations, constants A and B are adjusted by machine vision or machine learning algorithms.

In some implementations, the optical diverging component is located downstream of the display, as discussed above with respect to the second technique, "Zero Order Beam Divergence." The optical diverging component can be a defocusing element including a concave lens, such as concave lens 1802 in FIG. The optical diverging component may be a focusing element including a convex lens. The diffracted first portion of light is directed through an optical diverging component to form a holographic scene, while the display zero order light is diverged within the holographic scene. The light illuminating the display can be collimated, the display zero-order light can be collimated before reaching the optically diverging component, and the hologram is constructed so that the diffracted first portion of the light is optically divergent. It is constructed so that it converges before reaching the constituent elements. The optical diverging component can be a focusing element including a cylindrical lens. The optical diverging component can be a lenslet array including concave, convex, or cylindrical lenses, or combinations thereof. The optically diverging component is one or more holographic optical elements (HOEs) that are either added to the optical device or incorporated within one or more of the other diffractive layers of the optical device. It can be. The one or more HOEs may be configured to converge, diverge, or linearly focus light, or to direct the display zero-order light to regions outside the reconstruction cone of the holographic scene. It can be configured to add complex transfer functions. The region can include an annular or peripheral region or a portion of an annular or peripheral region. The light illuminating the display may be collimated and the hologram may include a diffracted first portion of the light such that the effect of the optically diverging component on the first portion of the light compensates for the shaping effect. It can be configured to be shaped with a shaping effect before reaching the optical diverging component.

In some examples, the hologram is constructed by adding a virtual lens, e.g., by adding a corresponding phase to each phase for each of the display elements, and a corresponding phase for each display element. The phase is compensated by optical diverging components such that the holographic scene corresponds to a respective phase for the display elements. The corresponding phase for each of the display elements is given by equation (16) below:
can be expressed by
During the ceremony,
represents the corresponding phase for the display element, λ represents the wavelength of the light, f represents the focal length of the optically diverging component, x and y represent the coordinates of the display element in the coordinate system, and a and b represent a constant.

In some examples, the hologram is created in 3D by moving the configuration cone relative to the display with respect to the global 3D coordinate system along a direction perpendicular to the display and a distance that corresponds to the focal length of the optically diverging component. It is configured in a software application, for example, Unity. The construction cone corresponds to the reconstruction cone and has the same apex angle as the viewing angle. The software application can generate object primitives based on the moved configuration cones in the global 3D coordinate system.

Process 3400 can include displaying the holographic scene on a two-dimensional (2D) screen, such as projection screen 1830 of FIG. 18, spaced apart from the display along a direction perpendicular to the display. The 2D screen can be moved along the direction to obtain different slices of the holographic scene on the 2D screen.

Process 3400 can further include directing light to illuminate the display. In some examples, light is directed by a beam splitter, e.g., beam splitter 1810 of FIG. 18, to illuminate the display, and the diffracted first portion of the light and the display zero-order light pass through the beam splitter. Transparent.

In some implementations, the display is illuminated with light at normal incidence, for example, as illustrated in FIG. 18 or 19A. In some implementations, the display is illuminated with light at an angle of incidence that can be greater than half the viewing angle, as illustrated in FIG. 19B or 19C.

In some implementations, as discussed above with respect to the third technique "Zero Order Optical Deviation," the hologram is constructed such that the diffracted first portion of the light is , forming a reconstruction cone that is the same as that formed by the diffracted first part of the light, while the reflected second part of the light, as illustrated in FIG. 19B or 19C, It is arranged so that it emerges from the display at the same reflected angle as the angle of incidence.

In some examples, the hologram is constructed by adding a virtual prism, e.g., by adding a corresponding phase to each phase for each of the display elements; are compensated by the angle of incidence so that the holographic scene corresponds to the respective phase for the display elements. The corresponding phase for each of the display elements is given by equation (17) below:
can be expressed by
During the ceremony,
represents the corresponding phase for the display element, λ represents the wavelength of the light, x and y represent the coordinates of the display element in the global 3D coordinate system, and θ represents the angle corresponding to the angle of incidence.

In some examples, the hologram is created on the surface of the display relative to the global 3D coordinate system by moving the configuration cone relative to the display relative to the global 3D coordinate system, e.g., as illustrated in FIG. 20B. by rotating the construction cone by an angle of rotation relative to the angle of incidence, where the angle of rotation corresponds to the angle of incidence.

In some implementations, the display zero order light is blocked to appear in the holographic scene, as discussed above with respect to the fourth technique, "zero order light blocking." The light suppression efficiency of the holographic scene can be 100%.

In some examples, the optical blocking component is located downstream of the display. The optical blocking component can include a plurality of microstructures or nanostructures. The optical blocking component can include a metamaterial layer, eg, metamaterial layer 2316 of FIGS. 23A-23B, or a louvered film, eg, the anisotropic transmitter of FIG. 28. The optical blocking component is configured to transmit a first beam of light having an angle less than a predetermined angle and block a second beam of light having an angle greater than a predetermined angle; The angle is less than the angle of incidence and greater than half the viewing angle. Thus, as illustrated in FIGS. 23A, 23B, the display zero-order light is blocked by the optical blocking component and the diffracted first portion of the light passes through the optical blocking component with a certain transmission efficiency. Transparent and forms a holographic scene. The transmission efficiency is a predetermined ratio, for example, 50%, 60%, 70%, 80%, 90%, or 99% or more.

In some implementations, process 3400 directs the light to illuminate the display by directing the light through an optical diffractive component on the substrate that is configured to diffract the light at an angle of incidence. Further comprising inducing. The optical diffractive component can be an outcoupler 1914 in FIG. 19A, 1964 in FIG. 19B or 19C, or a transmitted field grating structure 2414 in FIG. 24. In some examples, light is directed to the optical diffractive component through a waveguide coupler, such as in-coupler 1916 in FIG. 19A or 1966 in FIG. 19B or 19C. In some examples, light is directed to the optical diffractive component through a coupling prism, such as coupling prism 2111 of FIG. 21 or 2311 of FIG. 23A or 23B. In some examples, light is directed through the wedge-shaped surface of the substrate to the optical diffractive component, such as illustrated in FIG. 22, for example.

As illustrated in FIG. 23A or 23B, the optical diffractive component is formed on a first surface of the substrate facing the display, and the optical blocking component is opposite the first surface. The second surface of the substrate is formed on the second surface of the substrate.

In some implementations, as discussed above with respect to the fifth technique "Zero-order light redirection," the optical redirection component is located downstream of the display and the diffracted first portion of the light. The display is configured to transmit zero-order light to form a holographic scene and redirect zero-order light from the holographic scene. The optical redirection components include zero-order redirection grating structure 2416 in FIG. 24, 2616 in FIG. 26A, 2646 in FIG. 26B, 2666 in FIG. 26C or 26D, 2694 in FIG. 26E, 2716 in FIG. 27A, 2746 in FIG. 2816 in FIG. 28, 2916 in FIG. 29, 3016 and 3018 in FIG. 30A, 3046 and 3048 in FIG. 30B, 3114, 3116, and 3118 in FIG. or 3214, 3216, and 3218 in FIG. 32, or 3314, 3316, and 3318 in FIG.

The optical redirection component is configured to diffract the first beam of light having an angle that is the same as the predetermined angle with a substantially greater diffraction efficiency than the second beam of light having an angle that is different from the predetermined angle. The predetermined angle may be substantially the same as the angle of incidence. The optical redirection component can include one or more holographic gratings, such as a Bragg grating.

In some implementations, the optical diffractive component is formed on the first surface of the substrate facing toward the display, and the optical redirecting component is illustrated, for example, in FIGS. 24-33. The second surface of the substrate is formed on a second surface of the substrate opposite the first surface.

The optical redirection component directs the display zero-order light outside the holographic scene in three-dimensional (3D) space along at least one of an upward direction, a downward direction, a leftward direction, a rightward direction, or a combination thereof. It is configured so that it is diffracted into The light suppression efficiency of the holographic scene can be 100%. In some examples, as illustrated in FIG. 26A, the angle of incidence of the light is negative, e.g., −6° in air, and the diffraction angle of the display zero-order light diffracted by the optical redirection component is negative, eg -45° in air. In some examples, as illustrated in FIG. 26B, the angle of incidence of the light is positive in air, e.g., +6°, and the diffraction angle of the display zero order light diffracted by the optical redirection component is , positive in air, for example +45°. In some examples, as illustrated in FIG. 26C or 26D, the angle of incidence of the light is negative in air, e.g., −6°, and the display zero-order light is diffracted by the optical redirection component. The diffraction angle is positive in air, eg +45°. In some examples, the angle of incidence of the light is positive, +6° in air, and the angle of diffraction of the display zero-order light diffracted by the optical redirection component is negative, e.g., −45°, in air. be.

The optical redirection component can be covered by a second substrate, such as cover glass 2618 in FIG. 26A. The optical redirection component directs the display zero-order light to a light absorber, such as light absorber 2619 of FIG. 26A or FIG. 26B formed on at least one of the sides of the second substrate or the sides of the substrate. 2649. The second substrate can include an anti-reflection (AR) coating, such as AR coating 2682 of FIG. 26D on the surface of the second substrate opposite the optical redirection components. The anti-reflective coating is configured to transmit the display zero order light and prevent Fresnel reflections of the display zero order light. The anti-reflective coating is also configured to reduce or eliminate reflections of ambient light from the viewer and reflected from the viewer-facing front surface of the second substrate, e.g., AR coating 2682 in FIG. 26D. obtain. The final AR coating can be designed to not interfere with those of the five techniques described herein, depending on the characteristics of the final transition to air on the viewer side. Preventing Fresnel reflections from the front surface prevents the viewer from seeing themselves and the room lights reflected by the front surface. Deeper surfaces within the optical device have only relatively small refractive index changes, thus with minimal Fresnel reflections of the observer and room light returning towards the viewer, or the surface can also be AR coated. , or as in the case of the rear reflector of a display, the surface is behind multiple absorbing layers, such as linear polarizers, in which the ambient illumination can make a double pass and thus be attenuated, with a cumulative optical density of 0.2 to The effect can be enhanced by adding or incorporating layers of materials in the range of 1.0 to the device.

In some implementations, the display zero order light is p-polarized before reaching the second substrate. As illustrated in FIG. 27A, the optical redirection component directs the display zero-order light between the second substrate and the surrounding media such that the display zero-order light is completely transmitted through the second substrate. , for example, can be configured to be diffracted such that it is incident at Brewster's angle on the interface with air.

In some implementations, the display zero order light is s-polarized before reaching the second substrate. Process 3400 can further include converting the polarization state of the display zero order light from s-polarization to p-polarization. In some examples, converting the polarization state of display zero-order light includes an optical retarder (e.g., optical retarder 2747 of FIG. 27B) (and optionally (typically, with a linear polarizer). In some examples, converting the polarization state of the display zero-order light includes an optical retarder (e.g., optical retarder 2747 of FIG. 27C) (and optionally (typically, with a linear polarizer). An optical retarder can be formed on the side of the second substrate opposite the optical redirection component, and the optical retarder can be covered by a third substrate (eg, retarder cover glass 2762 of FIG. 27C).

In some implementations, as illustrated in FIG. 28, the optical blocking component is formed on the side of the second substrate opposite the optical redirecting component. The optical blocking component is configured to transmit the diffracted first portion of the light and absorb the display zero order light diffracted by the optical redirecting component. In some examples, the optical blocking component is configured to transmit a first beam of light having an angle less than the predetermined angle and absorb a second beam of light having an angle greater than the predetermined angle. Anisotropic transmitter (eg, anisotropic transmitter 2820 of FIG. 28) configured. The predetermined angle is greater than half the viewing angle and less than the diffraction angle at which the display zero order light is diffracted by the optical redirection component.

In some implementations, as illustrated in FIG. 29, the optical redirection component diffracts the display zero-order light to the interface between the second substrate and the surrounding medium below the critical angle. The display zero-order light that is configured to be incident at a large angle and is thus diffracted by the optical diffractive component is completely reflected at the interface. A light absorber, such as light absorber 2920 in FIG. 29, can be formed on the sides of the substrate and the second substrate and configured to absorb completely reflected display zero order light.

In some implementations, as illustrated in FIGS. 30A-33, the light includes a plurality of different colors of light, and the optical diffractive component reflects the plurality of different colors of light at an angle of incidence on the display. It is configured to cause diffraction. The optical redirection component includes a respective optical redirection subcomponent for each of the plurality of different colors of light.

In some implementations, as illustrated in FIG. 30B, each optical redirection subcomponent for a plurality of different colors of light has the same recording structure, or is adjacent to a thin optical index layer, contact recorded in layers, or recording structures separated only by adhesive layers. In some implementations, as illustrated in FIGS. 30A, 31A, 31B, 32, 33, each optical redirection subcomponent for a plurality of different colors of light may be separated by a cover glass, recorded in the corresponding recording structure.

The optical redirection component can be configured to diffract light of a plurality of different colors toward different directions and at different diffraction angles in 3D space. In some examples, as illustrated in FIGS. 31A-31B, the optical redirection component diffracts at least one of the plurality of different colors of light at at least one Brewster's angle at the interface. It is configured to allow the light to enter. The interface can include one of an interface between a top substrate and a surrounding medium or an interface between two adjacent substrates.

In some implementations, as illustrated in FIG. 32, the optical redirection component includes a first color of light (e.g., blue) and a second color of light (e.g., red) in a plane; It is also configured to diffract light of a third color (for example, green) that is perpendicular to the plane.

In some implementations, as illustrated in FIG. 31B, the optical redirection component includes at least two different optical components configured to diffract the same color of light of the plurality of different colors of light. Redirect sub-components (eg, redirection grids 3166-1, 3166-2 in FIG. 31B). Two different optical redirection sub-components can be arranged sequentially in the optical redirection component.

Directing the light to illuminate the display may include sequentially directing a plurality of different colors of light to illuminate the display in a series of time periods. In some implementations, as illustrated in FIG. 33, the optical redirection component directs light of the first color in the first state during all, some, or a portion of the first time period. A switchable light redirecting sub-component (e.g., 33 switchable green redirection grids 3316).

In some implementations, the switchable optical redirection sub-component diffracts light of the first color in the first state during all, some, or a portion of the first time period and diffracts the first color of light during the second time period. is configured to diffract light of a second color in a second state into all, some, or a portion of the second state.

The plurality of different colors of light can include a first color of light and a second color of light, the first color of light having a shorter wavelength than the second color of light. In the optical redirection component, a first optical redirection subcomponent for a first color of light is connected to a second optical redirection subcomponent for a second color of light, as illustrated in FIGS. 30A-33. Can be placed closer to the display than the redirection subcomponent.

In some implementations, the fringe planes of at least two optical redirection subcomponents for at least two different colors of light are oriented in substantially different directions.

In some implementations, the optical redirection component includes a first optical redirection component configured to diffract light of a first color and a first optical redirection component configured to diffract light of a second color. a second optical redirection component, and a second optical redirection component disposed between the first optical redirection subcomponent and the second optical redirection subcomponent, and wherein the first color of light passes through the second optical redirection component. at least one optical retarder (and optionally, a linear polarizer) configured to convert the polarization state of the first color of light such that the first color of light is transmitted through the light.

The second reflected portion of the light has an angle of reflection that is the same as the angle of incidence and propagates outside the holographic scene. In some examples, half of the viewing angle is within a range of -10 degrees to 10 degrees, or within a range of -5 degrees to 5 degrees. In some examples, the angle of incidence is -6 degrees or 6 degrees.

In some implementations, the optical redirection component allows the display zero-order light to pass through unaltered and redirects the diffracted first portion of the light away from the display zero-order light. The holographic scene is configured to form a holographic scene corresponding to a cone or truncated cone having a predetermined angle.

In some implementations, the optical redirection component redirects the display zero-order light toward the first direction and directs the diffracted first portion of the light in a second direction away from the first direction. is configured to redirect towards. For example, the diffracted first part of the light can be redirected to be perpendicular to the wedge-shaped surface of the substrate, and the display zero-order light can be redirected to hit the wedge-shaped surface beyond a critical angle. and can therefore undergo total internal reflection (TIR) back into the substrate.

Additional Aspects of Displaying Reconstructed Three-Dimensional Objects Implementations of the present disclosure may be implemented using a holographic light field, such as holographic light field 518 of FIG. 5A, 528 of FIG. 5B, 538 of FIG. 5C, or 548, 568 in FIG. 5E, 578 in FIG. 5F, 599-1 or 599-2 in FIG. 5H, 5I, 5J, or 5K, 2422 in FIG. 24, 2622 in FIG. 26A, 2632 in FIG. or 2652 in FIG. 26E, 2702 in FIG. 27A, 2732 in FIG. 27B or 27C, 2802 in FIG. 28, 2902 in FIG. 29, 3022 in FIG. 30A or 30B, 3122 in FIG. , 3224, provides a display system for displaying the reconstructed three-dimensional (3D) object. The techniques described herein can be applied to one or more holographic light fields, e.g., by using larger reflective displays, by using larger gratings, and/or by controlling the input light. (e.g., size or zero-order suppression), thereby improving the performance of the display system. For purposes of illustration only, the technique will be discussed with reference to system 3100 of FIG. 31A.

First Exemplary Method - Using a Larger Reflective Display One method for increasing the size of the holographic light field 3122 of FIG. 31A is to have a larger reflective display 3104 and an unchanged beam angle. The same optical geometry is constructed using a proportionally larger substrate 3111.

As the linear range of the reflective display 3104 increases, the front area of the substrate 3111 increases as the square of the increase in the linear range of the reflective display 3104. If the beam angle and beam distribution remain unchanged, the thickness of the substrate 3111 increases as the linear range of the reflective display 3104 increases. As a result, the volume of the substrate 3111 can increase as the cube of the linear range increase of the reflective display 3104. For example, doubling the width of reflective display 3104 while maintaining the same width-to-height aspect ratio of reflective display 3104 and the proportional thickness of substrate 3111 quadruples the entire surface area of substrate 3111 and Increase the volume of 3111 by 8 times. Finally, the large thickness and high cost of substrate 3111 may, for example, result in substrate 3111 having substantially no significant inclusions, absorption, scattering, birefringence, and/or other visible optical defects or imperfections. may be undesirable, as it may be desirable to maintain optical-grade clarity without containing

The weight of the substrate 3111 may also be undesirable. For example, substrate 3111 may have a thickness of about 20% of the height of reflective display 3104. As an example, for a 686 mm (27 inch) diagonal reflective display 3104 with a 16:9 aspect ratio (typical dimensions of a computer monitor), the substrate 3111 may have dimensions of 598 mm x 336 mm x 68 mm or more. . If such a substrate 3111 is made from a solid block of acrylic having a density of 1.17-1.20 g/cm ³ , the weight of the substrate 3111 may be at least 16 kg (35 lbs). For a similar diagonal 1,650 mm (65 inch) reflective display 3104 having an aspect ratio of 16:9, the substrate 3111 may be at least 165 mm thick and weigh at least 225 kg (495 lbs); This can be difficult to ship, install, and move. The mounting and support structures for such blocks of acrylic can also be large and heavy.

Furthermore, if all or part of the holographic light field 3122 is projected into viewing space in front of the final cover glass 3113, the holographic light field 3122 may be positioned proportionally further in front of the front cover glass 3113. It may be desirable (eg, more than 165 mm in front of a reflective display 3104 with a 1,650 mm diagonal). This can reduce field of view and resolution. If a smaller, zero, or negative Z-axis translation is applied, the holographic light field 3122 may appear deeper behind the front surface of the front cover glass 3113.

To address the above issues, the substrate 3111 can be made thinner, which may reduce its mass, cost, and provide the substrate with fewer constraints on its z-position and field of view.

In some embodiments, the substrate 3111 is a material with a lower density and/or index of refraction that allows for more extreme angles and changes in beam angle of the beam entering and exiting the substrate 3111. It can be made with For example, liquid-filled substrate 3111 can be used with a liquid, such as water or oil, that has a refractive index that may be less than that of acrylic (eg, 17% to 20% less). The liquid can be enclosed within a tank, which can help solve certain potential transportation and installation problems, as the tank can be transported empty and then filled on-site.

In certain embodiments, the angle of input light 3120 refracted into substrate 3111 may increase with respect to one or more wavelengths of input light 3120. This may allow the use of a relatively thin substrate 3111 for the input light 3120, for example to illuminate the same area of the reflective display 3104. In some cases, it may be desirable to select an angle to achieve a particular diffraction efficiency and/or to meet desired critical angle characteristics.

In some embodiments, the substrate 3111 is similar to, for example, the substrate 1252 of FIG. 12B or the substrate 1272 of FIG. 12C such that the angle of incidence of the input light 3120 on the field grating 3112 can be relatively large. Can be made into a wedge shape.

In certain embodiments, two or more illuminators can be used to illuminate different areas of the reflective display 3104, for example, from above and from below, respectively. For example, a first illuminator 3106 that provides a first input light 3120 to a first end surface of the substrate 3111 (e.g., the bottom end surface of the substrate 3111) may be used to provide a first region of the reflective display 3104 (e.g., , lower half) can be irradiated. A second illuminator (which is different from the first illuminator) that provides a second input light (which can be similar to the first input light 3120) to a second end surface of the substrate 3111 (e.g., a top end surface of the substrate 3111). 3106) can be used to illuminate only the second region (eg, the top half) of the reflective display 3104. Such an arrangement allows the reflective display 3104 to be fully illuminated while allowing the substrate 3111 to be relatively thin (e.g., allowing the thickness of the substrate 3111 to be halved). can do. Optionally, a third, fourth, or greater number of input lights are each input through different corresponding end faces of the substrate 3111 (e.g., the left end face and the right end face of the substrate 3111). Then, regions of reflective display 3104 (eg, left and right regions, respectively) can be respectively illuminated.

In some embodiments, the input light can illuminate different areas of the reflective display 3104 along different optical paths. For example, a first illuminator 3106 that provides first input light 3120 to an end surface of the substrate 3111 (e.g., a lower end surface of the substrate 3111) and directly illuminates the transmission field grating 3112 may can be used in combination with a second illuminator that provides a second input light to the end face (which may be the same end face used by one input light), but the second input light is first redirected. directed forward toward grating 3114 and then reflected toward transmission field grating 3112 such that the first input light illuminates a first region (e.g., the top half) of reflective display 3104; A second input light illuminates a second adjacent area (eg, the bottom half) of reflective display 3104. Such reflection of the second input light may be caused by total internal reflection (TIR) or reflection gratings at or before the surface of redirection grating 3114 (e.g., by an interface between substrate 3111 and redirection grating 3114). This can be achieved by using . Alternatively, a partially reflective surface (e.g., a 50:50 or sloped or patterned beam splitter) can be incorporated into the substrate 3111 to split a single input light 3120 in the substrate 3111 into two beams. This includes a first beam that travels directly to the transmission field grating 3112 with reduced optical power, and a first beam that travels away from the transmission field grating 3112 with also reduced optical power and then, e.g., TIR, or includes a second beam directed back towards the transmission field grating 3112 by a reflection grating at or before the surface of the redirection grating 3114.

In certain embodiments, the diffraction efficiency of the transmission field grating 3112 is such that only a selected fraction of the input light 3120 is directed toward the reflective display 3104 when the input light 3120 first encounters a subregion of the transmission field grating 3112. The input light 3120 may be patterned such that all or a portion of the remaining input light 3120 is reflected into the substrate 3111. The reflected input light 3120 in the substrate 3111 is further reflected by TIR onto the front surface of the substrate 3111, e.g. backwards towards the second sub-region of the transmission field grating 3112, The sub-regions are arranged in reflective display 3104 with adjusted diffraction efficiencies such that two such regions of transmission field grating 3112 illuminate two corresponding sub-regions of reflective display 3104 with substantially similar optical power. Join the second part towards. The process described above can be extended to three or more such sub-regions of the transmission field grating 3112 and thus to three or more corresponding sub-regions of the reflective display 3104.

In some embodiments, light that is not initially diffracted to the reflective display is recycled to illuminate the reflective display. For example, the diffraction efficiency of the transmission field grating 3112 is such that when the input light 3120 first encounters a first sub-region of the transmission field grating 3112, only a selected fraction of such input light 3120 is reflected in the reflective display 3104. The remaining input light 3120 can be patterned or selected such that all or a portion of the remaining input light 3120 is reflected onto the substrate 3111. Reflected input light 3120 is ultimately transmitted (e.g., by TIR within the substrate 3111 or via a direct path) to a reflective element (e.g., the absorber of FIG. 12B) attached to or following the end face of the substrate 3111 1203) and the reflective element reflects it back through the substrate 3111 (directly or after further TIR or diffraction redirection) to transmit the transmitted light. Re-illuminating the first sub-region of field grating 3112 or the second sub-region of transmission field grating 3112 causes it to diffract outward toward reflective display 3104.

In some embodiments, each of the sub-regions of the reflective display 3104 is made from an individual display device (e.g., LCoS) or any other reflective display device, and the reflective display 3104 is made from a smaller display device. It is formed by a tiled array of This allows differences in diffraction efficiency, and therefore device illumination, for each sub-region of the transmission field grating 3112 to be compensated for by operating such smaller display devices with different reflectivities.

In certain embodiments, a relatively high width to height aspect ratio of the reflective display is used to increase the size of the holographic light field. The thickness of the substrate 3111 generally depends on the illuminated height of the reflective display 3104 but not the illuminated width of the reflective display 3104, so as the aspect ratio of the reflective display 3104 increases, the thickness of the substrate The thickness of 3111 need not increase as its width necessarily increases without a corresponding increase in its height. For example, instead of a 16:9 width:height aspect ratio, a 20:9 aspect ratio may be used. Increasing the aspect ratio of the reflective display 3104 in this way can increase the size of the holographic light field since the viewer typically has two eyes in a primarily horizontal arrangement, resulting in stereoscopic viewing. .

In some cases, when multiple viewers observe a holographic light field display simultaneously, the viewers are likely positioned side by side (rather than one looking over the other's head), so The wider field of view provided by the high aspect ratio may be suitable for group viewing. Furthermore, it has been empirically observed that most viewers of holographic light fields, e.g. casual viewers, are more likely to move their heads from side to side rather than up and down, so again, having a wider High aspect ratios can be implemented to improve system performance.

In some cases, useful and comfortable holographic light field displays can have very high aspect ratios (strip or slit displays). For example, if grids 3112, 3114, 3116, and 3118 are horizontally tiled, a wider aspect ratio can be achieved with relatively thin substrate 3111.

In general, regardless of the aspect ratio of reflective display 3104 (and therefore of substrate 3111 and gratings 3112, 3114, 3116, and 3118), the width of input light 3120 is 3112, 3114, 3116, and 3118). For low aspect ratios of the reflective display 3104, the input light 3120 can have a gently elongated rectangular profile or cross-section (or even a square profile or cross-section), which is well away from the illuminator 3106. can be implemented by masking or otherwise cutting out large circular or elliptical beam profiles.

Second Exemplary Method - Using a Larger Grating If reflective display 3104 and substrate 3111 are expanded, transmission field grating 3112 and display zero-order redirection gratings 3114, 3116, and 3118 are also expanded to match. can do.

In some embodiments, the transmitted field grating 3112 can be divided into two or more regions, each utilizing input light that enters the substrate 3111 through a different edge surface of the substrate 3111, as described above. do.

In certain embodiments, larger gratings 3112, 3114, 3116, and 3118 can be produced by expanding the corresponding optical elements and recording materials of the respective production systems.

In some embodiments, the larger gratings 3112, 3114, 3116, and 3118 can be produced by tiled optical recording, with each sub-region of the grating being formed by smaller optical elements in a step-and-repeat process. and can be recorded sequentially using full-size recording material. This allows the use of smaller optical components, which are often relatively inexpensive. Additionally or alternatively, this allows the use of relatively inexpensive recording laser light sources, and/or the relatively wide range of laser technologies, wavelengths, and vendors available to provide such light sources. The use of lower recording capacity (eg, rather than increasing the recording exposure duration) may be possible. Such a tiled grid can also be used to provide multiple regions for extending the transmitted field grating 3112 using multiple input lights.

The edges of the tiled sub-regions of the grid can abut each other with slight gaps between the sub-regions of the grid. Optionally, the sub-regions can be seamlessly combined, or the sub-regions can slightly or substantially overlap. A combination of such approaches is possible. In some cases, slight gaps may not be visible or may have low viewer visibility. For example, when the holographic light field 3122 occupies an optical distance from the viewer that does not include the optical distance of the grating from the viewer, the gap is such that when the viewer's eye is focused on the holographic light field 3122, the focal point It may not match. In certain cases, slight overlap may have little or no visibility to the viewer. Substantial overlap, e.g. 50% overlap, between two sub-regions of the grid may be used to smooth and/or reduce the visibility of the tiling and/or to improve the final uniformity of the overlapping grid. can be implemented to improve.

In some cases, to reduce the visibility of such small gaps or overlaps between tiled sub-regions of the grating, the sub-regions of the grating are reflective as a tiled array of smaller display devices. It can be aligned with the gaps between smaller display devices forming display 3104.

In some cases, an effectively seamless grating with no significant gaps or significant overlap may be achieved by adding one or more layers to the recording reference and/or object beam optics when recording the subregion grating. including edge-defining elements, such as square, rectangular, or otherwise planar tiled openings, and during recording of the grid or grid, the edges are substantially tightly focused within the recording material; This can be implemented by projecting or re-imaging the edges formed as shown. Sharply defined edges can also be achieved when recording the grating of sub-areas, for example by using a reflection or transmission phase mask in the optical system of the recording reference and/or the object beam.

In some embodiments, larger gratings 3112, 3114, 3116, and 3118 can be fabricated using mechanical rather than optical means, such as embossing, nanoimprinting, or self-assembled structures; Such mechanically generated grids can also be tiled in one or more dimensions, for example by the use of roller embossing in a roll-to-roll system.

Third Exemplary Method - Controlling Input Light As discussed above, as the aspect ratio of the reflective display 3104 increases, a more extended rectangular profile for the input light 3120 may be desirable, and the illuminator 3106 A more elliptical beam profile from . Because many laser diodes produce elliptical beams, in some cases the desired beam profile from the illuminator 3106 can be determined by rotating the ellipticity of the laser diode source within the illuminator 3106, e.g. It can be implemented by mechanically or optically rotating the laser diode light source within 3106.

Because many laser diodes emit substantially polarized light, and certain other components of optical device 3110 may perform better for particular polarization orientations (e.g., (which may require polarization orientation), for example, by rotating all polarizations of the input light 3120 using a broad wavelength band half-wave retarder, or by using individual narrow wavelength band half-wave retarders. , it may be desirable to independently rotate the ellipticity and polarization orientation of the light source within the illuminator 3106 by rotating the polarization of each color of input light 3120 separately. Because the profile or cross-section of the input light 3120 can vary widely in both width and height, low-cost half-wave plates, such as polymer wave plates or liquid crystal wave plates, can be compared to high-cost half-wave plates made from, for example, quartz. half-wave plate.

In some embodiments, the uniformity of the input light 3120 is achieved by using an arrangement of optical elements such as apodizing optical elements or profile converters, e.g., lenses or holographic optical elements (HOEs), or, e.g. It can be improved by integrating rods or by using polarization recycling elements to perform Gaussian to top hat and/or circular to rectangular profile transformations.

In certain embodiments, anamorphic optics may be implemented. The aspect ratio of the reflective display 3104 is such that the desired degree of anamorphicity of the input light 3120 allows for cost-effectiveness within the illuminator 3106 without masking off and thus wasting an unacceptable percentage of the source power. It can be increased to such an extent that the threshold degree can be exceeded, which can be suitably provided by a high light source. In such cases, the width of the input light 3120 may be further increased by using anamorphic optics, e.g., an anamorphic or cylindrical lens, or an HOE acting as an anamorphic or cylindrical lens or mirror. can be done.

Exemplary System FIGS. 35A-C illustrate an example system 3500 for displaying reconstructed 3D objects. 36A-C each show the same views as FIGS. 35A-C of a system 3500, but with three colors of light (eg, red, green, blue) propagating through the system 3500.

A rectangular section (illustrated in FIG. 36A) of a substantially coaxial elliptical beam 3501 (e.g., made with three laser diodes of three different colors, such as red, green, and blue) from an illuminator 3501S ) is reflected from mirror 3502 and then refracted onto first surface 3503 of prism element 3504 . Beam 3501 has a width defined between the top and bottom beams, as illustrated in FIG. 36A. The light beams of different colors refracted into the prismatic element 3504 are stacked together along a first direction and spaced apart from each other along a second direction (e.g., as illustrated in FIG. 36A). (or overlap) (eg, as illustrated in FIG. 36B). A second surface 3505 of the prismatic element 3504 reflects the beam to a third surface 3506 of the prismatic element 3504 on which one or more transmission expansion gratings 3507 are optically stacked (typically one grating per color). let Each expanded grating is configured to be illuminated by its corresponding color at a relatively high angle of incidence within prismatic element 3504, for example 68°, and to diffract a portion of its illumination outwardly toward a series of reflectors 3508. ing. In effect, the grating 3507 divides the original rectangular section of the light beam 3501 from the laser diode by a substantial multiple (e.g., about 6 times) in one dimension (e.g., the width as illustrated in FIG. 36A). ). The light beam reflected to the prismatic element 3504 by the third surface 3506 and/or the expanded grating 3507 and/or the cover layer applied to the expanded grating 3507 is absorbed by the absorption layer 3504A applied to the surface of the prismatic element 3504. (eg, as illustrated in FIG. 36A).

Since the light incident on the grating 3507 is incident at a high angle, the depth of the prism element 3504 (e.g., the length of its surface 3505, at least a portion of which is reflective) should be relatively small. I can do it. The angle of incidence can exceed a critical value if light enters the grating 3507 from air at such a large angle (refractive index of about 1.0), causing all of the incident light to be reflected away from the grating. In system 3500, light is incident from a prismatic element 3504, which can be made, for example, from glass or acrylic with a high index of refraction (eg, about 1.5), so the angle of incidence does not exceed a critical angle.

In some embodiments, a reflector 3508 includes a beam (all three colors) 3509 that is diffracted outward by an expanded grating 3507 to reflect each color onto a cover plate 3510 attached to a shaped substrate 3511. three dichroic reflectors, one for each color, or two dichroic reflectors and a mirror for one color, or one dichroic reflector for two colors, and one dichroic reflector for one color, arranged in Can include a mirror for. Each colored light is incident on the cover plate 3510 at a different angle and over a different area of the cover plate 3510, and the colored light is then formed, for example, on the front surface 3512 of the shaped substrate 3511, and then on the shaped substrate 3511. In the cover plate 3510 (and subsequently shaped (within the substrate 3511). All three colors of light are incident on the array of reflective display devices 3515 at substantially the same angle for each color, and each color is incident on the array of reflective display devices 3515 at substantially the same angle for each color; Irradiate the entire area. The reflective display device passes through a field grating 3513, through a shaped substrate 3511, and into three stacked display (e.g., LCoS) zero-order suppression (LZOS) gratings 3516 attached to the front surface 3512 of the substrate 3511. (one for each color) (referred to elsewhere herein as redirection gratings, e.g., redirection gratings 3114, 3116, and 3118 of FIG. 31A) and causes each color to be reflected and outwardly diffracted. .

A portion of each color incident on reflective display device 3515 is reflected into display zero order beam 3521, and a portion of each color incident on each display device (e.g., LCoS) may be viewed by a viewer by each display device. , is diffracted into a corresponding holographic light field 3522, e.g., holographic light fields 3220, 3222, 3224 in FIG. As discussed elsewhere herein, the display zero-order suppression grating (or redirection grating) 3516 substantially diffracts light incident at the display zero-order angle, but at larger or smaller angles. An angle selective transmission grating that substantially transmits incident light and separates reflected display zero order light from the diffracted holographic light field. The rejected display zero-order light 3523 may exit the front face of the redirection grating at a substantial angle, as shown in FIG. 36B, or by TIR, as described elsewhere herein. , or can be reflected to the shaped substrate 3511 by a reflective grating.

In some embodiments, the tilt angles of the reflective elements 3508 are adjusted to achieve greater uniformity of diffraction from the transmission field gratings 3513 (e.g., to illuminate the transmission field gratings 3513 at their reproduction Bragg angles, or by illuminating the transmission field gratings 3513 at angles close to their reproduction Bragg angles) and/or to achieve greater brightness of the diffraction from the transmission field gratings 3513 (e.g., by illuminating the transmission field gratings 3513 at their reproduction Bragg angles). or by illuminating at an angle close to their reproduction Bragg angle). Such adjustments can be made substantially independently for each color by adjusting the tilt angle of each one of the reflective elements 3508.

In some embodiments, adjustments can be made as one-time adjustments during manufacturing or assembly. Optionally, adjustments can be made by an on-site user or installer. In certain embodiments, the adjustment utilizes color and/or brightness sensors to detect and optimize optical properties of the holographic light field, such as, for example, brightness, uniformity, color uniformity, or white point. can be executed automatically as part of a feedback loop. In some cases, the tilt angle of reflective element 3508 orthogonal to the tilt angle shown in FIG. 35B is adjusted to optimize performance of display system 3500. These approaches can be combined as needed.

In some cases, the tilt adjustment of the reflective element 3508 can be used to account for, for example, manufacturing and assembly tolerances, vibration and shock during shipping, storage, and use, thermal expansion and contraction, gratings, laser diodes, or other Compensate for changes or misalignment of display system components caused by factors such as wavelength-dependent component degradation and laser diode wavelength shifts due to operating temperature, operating duty cycle, and/or component-to-component variations can do.

In some cases, a substantially larger or smaller tilt adjustment of the reflective element 3508 may be used, for example, to tilt or rotate the shaped substrate 3511 backwards or forwards to improve the holographic light field. The alignment can be maintained even when the angle between the expanding prism 3504 and the molded substrate 3511 is changed from substantially 90° by tilting them upward or downward, respectively (as shown in FIG. 35B). ).

The center of the beam from the laser diode can be offset to achieve relatively uniform illumination on the reflective display 3515, which can also maintain color uniformity in the holographic light field. Slight differences in the paths traveled by each color to and from the display device 3515 (generally due primarily to the chromatic dispersion of the beams) may cause, for example, the differences between the three Color intensity can be slightly shifted. This can also be corrected by adjusting the diffraction efficiency of the reflective display device 3515 (eg, in one dimension or two dimensions) in a spatially modified manner. Because the diffraction efficiency is a function of a computer-generated hologram (CGH), or a constant or tunable spatially varying transmittance or absorbance before or after the display device 3515 (e.g., in one dimension or two dimensions). Such adjustments can be made on the fly by utilizing the elements that have.

In some cases, input light 3517 to substrate 3511 (e.g., as illustrated in FIG. 36B) is p-polarized at the edge surface of substrate 3511 such that input light 3517 is cover glass 3510) to reduce Fresnel losses at the surface, or the surface can be sloped or anti-reflective coated to reduce such Fresnel losses. A broadband half-wave retarder fixed at or after the surface can convert such p-polarized light to s-polarized light if that is the required or desired polarization for the transmission field grating 3513.

In some cases, a broadband retarder positioned between the transmitted field grating 3513 and the reflective display device 3515 is used to further adjust the polarization of the illumination light for the reflective display device 3515 to provide a reflective display. A necessary or desired or optimal polarization state can be provided to the device 3515. Such a retarder can be fixed to the exit face of the field grating 3513 or to the outer surface of the reflective display device 3515, or both, and is a half-wave plate to provide p-polarized or s-polarized light. or a quarter wave plate to provide circularly polarized light, or a spatial and/or quarter wave plate to provide circularly polarized light, or a spatial and/or Or it can have another value of delay that can vary in time and/or wavelength. Insofar as such a waveplate provides a polarization state for the reflected holographic light field from the reflective display device 3515, this may affect the desired or optimal polarization of subsequent polarization dependent elements, e.g. The polarization state may not be the same. In some cases, one or more additional waveplates may be used to further adjust the polarization to fill the element or elements, either uniformly or spatially or temporally or chromatically. It is possible to provide in front of such an element or elements with varying delays.

In some cases, the optical distance between the substrate 3511 and the combined reflective element 3508 is proportional to allow the three colors of light to be further separated in their reflection of the reflective element 3508. so that each color is reflected by the corresponding reflective element without passing through one or two other reflective elements, or three colors of light are transmitted through the other reflective elements. They can even be made large enough to be separated enough to be reflected using three mirrors.

In certain embodiments, the combined reflective elements 3508 are positioned and tilted such that the illumination of each of the reflective elements 3508 comes from substantially different directions rather than from substantially optically coaxial laser beams. be able to. This allows the illuminator 3501S to be split into two or three separate illuminators, each providing one or two of the three illumination colors, which are within the illuminator 3501S. may be cheaper and/or more efficient than using an optical system to combine the light from three laser diodes into a combined white input light providing input light 3501.

In some embodiments, the shaped substrate 3511 can be formed monolithically, e.g., by computer numerical control (CNC) machined from a larger block of material, and can be formed from two or more can be formed by optically combining or indexing simpler (and therefore more manufacturable) shapes, or by additive or subtractive manufacturing techniques.

In certain embodiments, a reflective display 3515 (or an array of reflective display devices 3515) with a larger vertical extent can be illuminated by increasing the height of the input light 3517, which increases the display illumination. The input light 3517 actually enters the cover glass 3510 (which may be omitted) at the tip of the shaped substrate 3511 forming a first lower cutoff for display illumination and an upper cutoff for display illumination. The corner 3518 of the shaped substrate 3511 forming the lower cutoff of 2 is affected by the missing input light 3517.

In some embodiments, the illumination of the reflective display 3515 is at an angle of about 6°, since the transmission field grating 3513 can also function as a zero-order suppression element similar to the redirection grating 3516. , can be changed to approximately 0°. In such embodiments, the field grating 3513 can reflect rather than transmit the specularly reflected zero-order light from the reflective display 3515 in the shaped substrate 3511, and the TIR directs it upwardly. and can be led from the top of the shaped substrate 3511 or to an absorber 3524 formed thereon. Using the field grating 3513 in combination with the redirection grating 10016 at or near 0° reduces residual displayed zero-order light to a very high degree, e.g., less than 2% residual displayed zero-order light, or even <1 %.

In certain embodiments, when a one-dimensional suppression grid is used, the display zero-order suppression appears as a dark band across the reflective display 3515, rather than a point, and the zero-order of each illuminated color falls within this dark band. It is visible only as a point of that color. If the viewer is more likely to view reflective display 3515 from above than perpendicular to reflective display 3515, as is typically the case with a tabletop or tabletop display, the system It may be configured to position the band so that it is above (but in angular space, close to) the holographic light field that is less likely to be noticed or is unfavorable, rather than below or to either side. . Similarly, if the viewer is likely to view the display from below the normal and perpendicular to the reflective display 3515, the system may be configured to position the band so that it is below the holographic light field. Can be configured. If most viewers view the display using two primarily horizontally distributed eyes, the band can be placed above or below the holographic light field instead of to the left or right.

In some embodiments where the illuminator 3501S is derived from a light source with a spectral bandwidth on the order of a few nanometers or tens of nanometers, the diffraction at the expanded grating 3505 and the field grating 3507 is caused by the radiation incident on the reflective display 3515. Light can be spectrally dispersed. The illuminating light then has spectral diversity (from the spectral bandwidth of the laser diode) and spatial diversity (from the dispersion of the light from the laser diode by these gratings and, to a lesser extent, from the source size of the laser diode). can be shown. These multiple orthogonality diversities can cause a significant reduction in visible laser speckle in the holographic optical field compared to that provided solely by the spectral and spatial diversity of the laser diode itself. .

In some embodiments, the expanded grating 3505 can fully or partially collimate the input light 3501 in one or two lateral directions, eliminating the need for laser diode collimation in the illuminator 3501S. The optical power can be configured to reduce or eliminate.

The angles of incidence of input light 3517 on cover plate 3510 may be selected such that two or more such angles of incidence are substantially equal, in which case a single such reflective element The number of reflective elements 3508 may be reduced as the number of reflective elements 3508 may be sufficient to reflect . Additionally, the final reflective element at 3508 may be provided as a reflective coating on the surface of the previous reflective element or within its substrate, which may be wedge-shaped to provide different angles of reflection for this final reflector.

Implementations of the subject matter and functional operations described herein may be implemented in computers including digital electronic circuits, specifically embodied computer software or firmware, the structures disclosed herein and structural equivalents thereof. It can be implemented in hardware, or a combination of one or more thereof. Implementations of the subject matter described herein include a computer program encoded on a tangible, non-transitory computer storage medium for execution by or for controlling the operation of a data processing device. It may be implemented as one or more computer programs, such as one or more modules of instructions. Alternatively or additionally, the program instructions may be a machine-generated electrical signal, an optical signal, generated to encode information for transmission to a suitable receiving device, for execution by a data processing device. or can be encoded on an artificially generated propagating signal, such as an electromagnetic signal. A computer storage medium can be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or a combination of one or more thereof.

The term "data processing apparatus," "computer," or "electronic computing device" (or equivalent as understood by those skilled in the art) refers to data processing hardware, such as a programmable processor, computer, or includes all kinds of apparatus, devices and machines for processing data, including processors or computers. The device may also be or further include special purpose logic circuits, such as a central processing unit (CPU), an FPGA (field programmable gate array), or an ASIC (application specific integrated circuit). In some implementations, data processing devices and special purpose logic circuits can be hardware-based and software-based. The apparatus optionally includes code that creates an execution environment for a computer program, such as code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more thereof. I can do it. This specification contemplates the use of data processing devices with or without conventional operating systems.

A computer program, which may also be referred to as a program, software, software application, module, software module, script, or code, may be written in any form of programming language, including a compiled or interpreted language, or a declarative or procedural language. It may be written as a stand-alone program or deployed in any form including modules, components, subroutines, or other units suitable for use in a computing environment. A computer program can, but need not, correspond to files in a file system. The program may be part of a file holding one or more scripts stored in other programs or data, for example a markup language document, a single file dedicated to the program in question, or a plurality of coordinated files. For example, one or more modules, subprograms, or portions of code may be stored in a storage file. A computer program can be deployed to run on one computer or multiple computers located at one site or distributed across multiple sites and interconnected by a communications network. Although portions of the program illustrated in the various drawings are shown as individual modules that implement various features and functionality through various objects, methods, or other processes, the program may instead be implemented as necessary. Depending on the application, it may include several submodules, third party services, components, libraries, etc. Conversely, the features and functionality of various components can be combined into a single component as desired.

The processes and logic flows described herein are performed by one or more programmable computers executing one or more computer programs to perform functions by operating on input data and producing output. can do. The processes and logic flows can also be executed, and the devices can also be implemented, as special purpose logic circuits such as CPUs, GPUs, FPGAs, or ASICs.

A computer suitable for the execution of a computer program may be based on a general purpose or special purpose microprocessor, both, or any other type of CPU. Generally, a CPU receives instructions and data from read only memory (ROM) and/or random access memory (RAM). The main elements of a computer are a CPU for implementing or executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also includes or is operably coupled to and receives data from one or more mass storage devices for storing data, e.g., magnetic disks, magneto-optical disks, or optical disks. , or transfer data to it, or both. However, the computer does not need to have such a device. Additionally, the computer may be connected to another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device, such as a Universal Serial Bus ( (USB) can be embedded in a flash drive.

Computer readable media (transitory or non-transitory, as appropriate) suitable for storing computer program instructions and data include, by way of example, semiconductor memory devices such as erasable programmable read only memory (EPROM). All forms of non-volatile memory, media and memory devices, including , electrically erasable programmable read only memory (EEPROM), and flash memory devices, magnetic disks, such as internal hard disks or removable disks, magneto-optical disks, and CD- Includes ROM, DVD-R, DVD-RAM, and DVD-ROM discs. Memory stores caches, lookup tables, classes, frameworks, applications, backup data, jobs, web pages, web page templates, database tables, repositories that store business and dynamic information, and any parameters, variables, algorithms, Various objects or data may be stored, including instructions, rules, constraints, or any other suitable information, including references. Additionally, memory may include any other suitable data such as logs, policies, security or access data, report files, and the like. The processor and memory may be supplemented by or incorporated with special purpose logic circuits.

To provide user interaction, implementations of the subject matter described herein include display devices, such as cathode ray tubes (CRTs), liquid crystal displays (LCDs), light emitting Implementation on a computer with a diode (LED), holographic or light field display, or plasma monitor, keyboard and pointing device, such as a mouse, trackball or trackpad, that allows the user to provide input to the computer I can do it. Input may also be provided to the computer using a touch screen, such as a pressure-sensitive tablet computer surface, a multi-touch screen using capacitive or electrical sensing, or other types of touch screens. Other types of devices may be used to provide interaction with the user as well, e.g. the feedback provided to the user may be arbitrary, such as visual feedback, auditory feedback, or haptic feedback. Input from the user can be received in any form, including acoustic, audio, or tactile input. In addition, the computer may send the document to the device used by the user, for example, by sending a web page to the web browser of the user's client device in response to a request received from the web browser, and then send the document to the device used by the user. By receiving, it is possible to interact with the user.

The term "graphical user interface" or "GUI" may be used in the singular or plural to describe each of one or more graphical user interfaces and specific graphical user interface displays. Thus, a GUI may represent any graphical user interface, including, but not limited to, a web browser, touch screen, or command line interface (CLI) that processes information and efficiently presents information results to a user. . Generally, a GUI may include some or all of the user interface (UI) elements associated with a web browser, such as interactive fields, pull-down lists, and buttons, that can be operated on by a business suite user. These and other UI elements may relate to or represent functionality of a web browser.

Implementations of the subject matter described herein include back-end components, e.g., as data servers, or middleware components, e.g., application servers, or front-end components, e.g. A client computer having a graphical user interface or web browser capable of interacting with an implementation of the subject matter described herein, or one or more such back-end components, middleware components, or front-ends. It can be implemented in a computing system including any combination of components. The components of the system may be interconnected by any form or medium of wired or wireless digital data communication, such as a communication network. Examples of communication networks include local area networks (LANs), radio access networks (RANs), metropolitan area networks (MANs), wide area networks (WANs), Worldwide Interoperability for Microwave Access (WIMAX), Examples include wireless local area networks (WLANs) using 902.11a/b/g/n and 902.20, all or part of the Internet, and any other communication system at one or more locations. . The network may communicate, for example, Internet Protocol (IP) packets, Frame Relay frames, Asynchronous Transfer Mode (ATM) cells, voice, video, data, or other suitable information between network addresses.

A computing system can include clients and servers. Clients and servers generally interact remotely with each other, typically through a communications network. The relationship between clients and servers is created by computer programs running on their respective computers and having a client-server relationship with each other.

In some implementations, any or all of the components of a computing system, both hardware and software, may interface with each other using application programming interfaces (APIs) or service layers; Can interface with surfaces. The API may include specifications for routines, data structures, and object classes. An API may be either computer language independent or computer language dependent and may refer to a complete surface, a single function, or even a set of APIs. The service layer provides software services to the computing system. The functionality of the various components of the computing system may be accessible to all service consumers through this service layer. Software services provide reusable, defined business functionality through defined interfaces. For example, the surface may be software written in any suitable language that provides data in any suitable format. The API and service layer may be integrated or stand-alone components in relation to other components of the computing system. Additionally, any or all portions of the service layer may be implemented as a child or submodule of another software module, enterprise application, or hardware module without departing from the scope of this specification.

Although this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or what may be claimed, but rather as limitations on the scope of any particular invention or what may be claimed. It should be construed as a description of features that may be implementation-specific. Certain features that are described herein in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Furthermore, although features may be described as operative in a particular combination and may initially be claimed as such, one or more features from the claimed combination may in some cases be excluded from the combination. The claimed combination may be directed to a subcombination or a variation of a subcombination.

Specific implementations of the subject matter are described. Other implementations, modifications, and substitutions of the described implementations are within the scope of the following claims, as will be apparent to those skilled in the art. Although acts are shown in the drawings or in the claims in a particular order, this does not mean that such acts may be performed in the particular order shown or in sequential order to achieve a desired result. It is not to be understood that this or that all illustrated operations are required to be performed (some operations may be considered optional). In certain situations, multitasking or parallel processing may be performed when deemed advantageous and appropriate.

For the sake of brevity, conventional techniques for the construction, use, and/or the like of holographic gratings, LCOS devices, and other optical structures and systems may not be described in detail herein. Moreover, the connecting lines illustrated in the various figures contained herein are intended to represent example functional relationships, signal or optical paths, and/or physical couplings between the various elements. It is noted that many alternative or additional functional relationships, signal or optical paths, or physical connections may exist in an exemplary holographic grating, LCOS, or other optical structure or system and/or its components. sea bream.

The detailed description of the various exemplary embodiments herein refers to the accompanying drawings and photographs that illustrate the various exemplary embodiments by way of illustration. Although these various exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure, other exemplary embodiments may be realized and logically It is to be understood that physical, optical, and mechanical changes may be made without departing from the spirit and scope of the disclosure. Accordingly, the detailed description herein is presented by way of illustration only and not as a limitation. For example, the steps described in any of the method or process descriptions may be performed in any suitable order and are not limited to the order presented unless explicitly stated. Additionally, any of the functions or steps may be outsourced to or performed by one or more third parties. Modifications, additions, or omissions may be made to the systems, devices, and methods described herein without departing from the scope of the disclosure. For example, system and device components may be integrated or separated. Moreover, the operations of the systems and apparatus disclosed herein may be performed by more, fewer, or other components, and the methods described may involve more, fewer, or other steps. may include.

As used herein, "each" refers to each member of a set or each member of a subset of a set. Furthermore, any reference to the singular may include a plurality of exemplary embodiments, and any reference to two or more elements may include a singular exemplary embodiment. Although specific advantages are enumerated herein, various exemplary embodiments may include some, none, or all of the enumerated advantages.

Benefits, other advantages, and solutions to problems are described herein with respect to certain exemplary embodiments. However, any benefit, advantage, solution to a problem, and any element that makes or could make any benefit, advantage, or solution more significant is important, necessary, or essential to the present disclosure. It should not be construed as a unique feature or element. Accordingly, the scope of the disclosure is not limited except by the appended claims, and references to an element in the singular mean "one and only one" unless explicitly stated otherwise. rather, it means "one or more." Furthermore, when a phrase similar to "at least one of A, B, and C" or "at least one of A, B, or C" is used in the claims or the specification, This phrase means that only A may be present in the exemplary embodiment, only B may be present in the exemplary embodiment, only C may be present in the exemplary embodiment, or element A, to be taken to mean that any combination of B and C, e.g., A and B, A and C, B and C, or A and B and C, may be present in a single exemplary embodiment is intended.

Therefore, the description provided above of the example implementations does not define or constrain the specification. Other changes, substitutions, and permutations are possible without departing from the spirit and scope of this specification.

Claims (76)

An optical device,
a first optical diffractive component;
a second optical diffractive component;
a color selective polarizer between the first optical diffractive component and the second optical diffractive component;
When a first light beam comprising light of a first color in a first polarization state is incident on the first optical diffractive component, the first optical diffractive component is in the first polarization state. diffracting the first color light;
When a second light beam comprising a second color of light in a second polarization state is incident on the color selective polarizer, the color selective polarizer directs the second light beam to the first light beam. into a third light beam comprising light of said second color in a polarization state of said first color, said second color being different from said first color, said second polarization state being different from said first color; Unlike the polarization state,
when the third light beam is incident on the second optical diffractive component, the second optical diffractive component diffracts the second color of light in the first polarization state;
The diffraction efficiency with which the first optical diffractive component diffracts the second color of light in the second polarization state is such that the first optical diffractive component diffracts the first color of light in the first polarization state. An optical device that diffracts colored light with substantially less diffraction efficiency. An optical device,
a first optical diffractive component;
a second optical diffractive component;
a color selective polarizer between the first optical diffractive component and the second optical diffractive component;
When light of a first color is incident on the first optical diffractive component at a first angle of incidence and in a first state of polarization, the first optical diffractive component diffracting colored light at a first diffraction angle with a first diffraction efficiency;
Light of a second color different from the first color of light is applied to the first optical diffractive component at a second angle of incidence in a second polarization state different from the first polarization state. upon incidence, the first optical diffractive component diffracts the second color light with a diffraction efficiency that is substantially less than the first diffraction efficiency;
When the second color light in the second polarization state is incident on the color selective polarizer, the color selective polarizer changes the polarization state of the second color light to the second color light. from the polarization state to the first polarization state,
When the second color of light is incident on the second optical diffractive component at the second angle of incidence and in the first polarization state, the second optical diffractive component An optical device that diffracts light of a second color at a second diffraction angle with a second diffraction efficiency. An optical device,
i) diffracting light of a first color in a first polarization state incident at a first angle of incidence at a first diffraction angle with a first diffraction efficiency; and ii) incident at a second angle of incidence. a first optical diffractive component configured to diffract light of a second color in a second polarization state with a diffraction efficiency that is substantially less than the first diffraction efficiency;
a color configured to rotate the polarization state of light of the second color in the second polarization state incident on the color selective polarizer from the second polarization state to the first polarization state; a selective polarizer;
a second optical diffraction arrangement configured to diffract light of the second color in the first polarization state incident at the second angle of incidence at a second diffraction angle and with a second diffraction efficiency; comprising an element and
An optical device, wherein the color selective polarizer is between the first optical diffractive component and the second optical diffractive component. the second optical diffractive component diffracts light of the first color in the second polarization state at the first angle of incidence with a diffraction efficiency that is substantially less than the second diffraction efficiency; It is configured to
Optionally, the first optical diffractive component, the color-selective polarizer, and the second optical diffractive component are configured such that the first color of light and the second color of light are Optical device according to any one of the preceding claims, wherein the optical device is stacked one after the other such that the first optical diffractive component is incident on the first optical diffractive component before the second optical diffractive component. a third optical diffractive component;
a second color selective polarizer between the second optical diffractive component and the third optical diffractive component;
The second color selective polarizer changes the polarization state of the third color light when the third color light is incident on the second color selective polarizer in the second polarization state. the third optical diffractive component is configured to rotate from the second polarization state to the first polarization state, the third optical diffractive component configured to rotate light of the third color to the third optical diffractive component; configured to diffract the third color light at a third diffraction angle with a third diffraction efficiency when the light is incident at a third incident angle and in the first polarization state;
Optionally, the color selective polarizer is configured to rotate the polarization state of the first color light from the first polarization state to the second polarization state, and the color selective polarizer is configured to rotate the polarization state of the first color light from the first polarization state to the second polarization state, a color-selective polarizer that changes the polarization state of the second color light from the first polarization state to the second polarization state without rotation of the polarization state of the first color light. It is configured to rotate to the state
Optionally, the polarization state of each of the first color light and the second color light is changed to the second color light without rotation of the polarization state of the third color light. a third color-selective polarizer configured to rotate from a polarization state to the first polarization state, wherein the third optical diffractive component is configured to rotate between the second color-selective polarizer and the first polarization state; further comprising a third color-selective polarizer between the third color-selective polarizer;
Optionally, the third optical diffractive component receives light of the first color and the the first optical diffraction component is configured to diffract each of the second colors of light, the first optical diffraction component diffracting the third color of light incident in the second diffraction state from the first the second optical diffractive component is configured to diffract light of the first color incident in the second state of polarization and the second optical diffractive component is configured to diffract the light of the first color and the second configured to diffract each of the three colors of light with a diffraction efficiency substantially lower than the second diffraction efficiency,
Optionally, said second color-selective polarizer comprises a pair of first and second sub-polarizers, said first sub-polarizer for controlling light of said first color. and rotating the polarization state of the second color light from the first polarization state to the second polarization state without rotating the polarization state of each of the third color light. The second sub-polarizer is configured to polarize the third color of light without rotating the polarization state of each of the first color light and the second color light. configured to rotate the polarization state of light from the second polarization state to the first polarization state;
Optionally, the polarization state of the first color light is changed to the polarization state of the second color light without rotation of the polarization state of each of the second color light and the third color light. a fourth color-selective polarizer configured to rotate from the fourth color-selective polarizer to the first polarization state, the first optical diffractive component being configured to rotate from the fourth color-selective polarizer to the first polarization state; 5. The optical device of claim 4, further comprising a fourth color-selective polarizer between the selective polarizers. each of the first optical diffractive component, the second optical diffractive component, and the third optical diffractive component comprises a respective holographic grating formed in a recording medium;
Optionally, the recording medium comprises a photosensitive polymer;
Optionally, the recording medium is optically transparent;
Optionally, said respective holographic grating is fixed to said recording medium;
Optionally, each of the first optical diffractive component, the second optical diffractive component and the third optical diffractive component comprises a carrier film attached to a side of the recording medium;
Optionally, each of the first optical diffractive component, the second optical diffractive component, and the third optical diffractive component is on another side of the recording medium opposite the carrier film. optionally, the carrier film of the first optical diffractive component is attached to a first side of the color-selective polarizer, and the carrier film of the first optical diffractive component is attached to a first side of the color-selective polarizer; the diffractive substrate of the diffractive component is attached to a second, opposite side of the color-selective polarizer, and the carrier film of the second optical diffractive component is attached to the second, opposite side of the color-selective polarizer; 5. The diffractive substrate of the second optical diffractive component is attached to a second opposite side of the second color-selective polarizer. Optical device described in. further comprising a substrate;
the first optical diffractive component is between the substrate and the color selective polarizer;
Optionally, the optical device further comprises an anti-reflection coating on the surface of the substrate;
Optionally, the optical device further comprises a front surface and a back surface,
Optionally, the first color of light and the second color of light are incident on the front surface, and the optical device further comprises an anti-reflection coating on the rear surface. The optical device according to item 1. a plurality of optical components, including the first optical diffractive component, the color selective polarizer, and the second optical diffractive component;
7. The optical device of any one of the preceding claims, wherein two adjacent optical components of the plurality of components are attached together through an index matching material. each of the first optical diffractive component and the second optical diffractive component comprises a respective Bragg grating formed in a recording medium;
each Bragg grating comprises a plurality of fringe planes, the plurality of fringe planes having a fringe tilt angle θ _t and a fringe spacing Λ perpendicular to the fringe plane within the volume of the recording medium;
Optionally, the respective Bragg gratings have a respective diffraction angle θ _m according to the Bragg equation mλ=2 n Λ sin (θ _m −θ _t ), where λ represents the respective wavelength of a certain color of light in vacuum, n represents the refractive index within the recording medium, and θ _m represents the wavelength of the recording medium. represents the m-th diffraction order Bragg angle in the medium, _θt represents the fringe slope in the recording medium,
Optionally, each of the first angle of incidence and the second angle of incidence is substantially the same as the On Bragg angle, and each of the first angle of diffraction and the second angle of diffraction is , is substantially identical to the first-order Bragg angle,
Optionally, the fringe tilt angle of each of the Bragg gratings is substantially equal to 45 degrees;
Optionally, the thickness of the recording medium is more than an order of magnitude greater than the fringe spacing;
Optionally, the thickness of the recording medium is about 30 times greater than the fringe spacing;
Optionally, the first diffraction angle and the second diffraction angle are substantially the same as each other;
Optionally, each of the first diffraction angle and the second diffraction angle is in a range of -10 degrees to 10 degrees;
Optionally, each of the first diffraction angle and the second diffraction angle is substantially the same as 0 degrees;
Optionally, each of the first diffraction angle and the second diffraction angle is in a range of -7 degrees to 7 degrees;
Optionally, each of the first diffraction angle and the second diffraction angle is substantially the same as 6 degrees;
Optionally, each of said first diffraction angle and said second diffraction angle is in a range of 70 degrees to 90 degrees;
Optionally, the first diffraction angle and the second diffraction angle are substantially the same as each other, an optical device according to any one of the preceding claims. the first polarization state is s-polarized light, and the second polarization state is p-polarized light;
the first optical diffraction component is configured to diffract incident light of the second color in the second polarization state with the diffraction efficiency at least one order of magnitude less than the first diffraction efficiency; the color-selective polarizer is configured not to rotate the polarization state of the first color light; and the optical device rotates the polarization state of the second color light. a second color-selective polarizer configured to rotate the polarization state of the first color light from the second polarization state to the first polarization state without rotation; , wherein the first optical diffractive component further comprises a second color-selective polarizer between the second color-selective polarizer and the color-selective polarizer. Optical device according to any one of the preceding claims, in which one is valid. the first optical diffractive component comprises a first diffractive structure, the second optical diffractive component comprises a second diffractive structure,
The optical device includes a first reflective layer and a second reflective layer, the first reflective layer being between the first diffractive structure and the second diffractive structure, and the second reflective layer a diffractive structure is between the first reflective layer and the second reflective layer,
The first diffraction structure is configured to: i) diffract first-order and zero-order light of the first color that is incident on the first diffraction structure at the first angle of incidence; , at the first diffraction angle, and the zeroth order is transmitted at the first angle of incidence; ii) incident on the first diffractive structure at the second angle of incidence; Transmitting the light of the second color;
The first reflective layer is configured to: i) fully reflect light of the first color incident on the first reflective layer at the first angle of incidence; and ii) at the second angle of incidence. and transmitting the light of the second color that is incident on the first reflective layer,
The second diffraction structure is configured to diffract first-order and zero-order light of the second color that is incident on the second diffraction structure at the second incident angle, and the first-order is , the zeroth order is transmitted at the second angle of incidence;
3. The method of claim 1, wherein the second reflective layer is configured to completely reflect light of the second color incident on the second reflective layer at the second angle of incidence. Optical devices described in Section. An optical device,
a first optical diffractive component comprising a first diffractive structure;
a second optical diffractive component comprising a second diffractive structure;
a first reflective layer;
a second reflective layer;
the first reflective layer is between the first diffractive structure and the second diffractive structure,
the second diffraction structure is between the first reflective layer and the second reflective layer,
When light of a first color is incident on the first diffraction structure at a first angle of incidence, the first diffraction structure diffracts the first-order and zero-order light of the first color, and is diffracted at a first diffraction angle, the zeroth order is transmitted at the first angle of incidence,
When light of a second color is incident on the first diffraction structure at a second angle of incidence, the first diffraction grating transmits the light of the second color at the second angle of incidence;
When the first color light is incident on the first reflective layer at the first incident angle, the first reflective layer completely reflects the first color light;
When the light of the second color is incident on the first reflective layer at the second angle of incidence, the reflective layer transmits the light of the second color at the second angle of incidence;
When the light of the second color is incident on the second diffraction structure at the second angle of incidence, the second diffraction structure diffracts the first-order and zero-order light of the second color, the first order is diffracted at a second diffraction angle, the zero order is transmitted at the second angle of incidence,
The optical device, wherein the second reflective layer completely reflects the second color light when the second color light is incident on the second reflective layer at the second angle of incidence. An optical device,
a first diffractive structure, the first diffractive structure comprising: i) diffracting first-order and zero-order first-color light incident on the first diffraction structure at a first angle of incidence; ii) a second color that is incident on the first diffractive structure at a second angle of incidence; a first optical diffractive component comprising a first diffractive structure configured to transmit light of;
i) fully reflecting the first color of light incident on the first reflective layer at the first angle of incidence; and ii) incident on the first reflective layer at the second angle of incidence. a first reflective layer configured to transmit light of the second color;
a second diffraction structure configured to diffract first-order and zero-order light of the second color that is incident on the second diffraction structure at the second incident angle, the first order being: a second optical diffractive component comprising a second diffractive structure configured to diffract at a second diffraction angle, the zero order being transmitted at the second angle of incidence; and,
a second reflective layer configured to completely reflect the light of the second color that is incident on the second reflective layer at the second incident angle,
The first reflective layer is between the first diffractive structure and the second diffractive structure, and the second diffractive structure is between the first reflective layer and the second reflective layer. In between is an optical device. An optical device,
a first optical diffractive component comprising a first diffractive structure configured to diffract light of a first color having a first angle of incidence at a first angle of diffraction;
a second optical diffractive component comprising a second diffractive structure configured to diffract light of a second color having a second angle of incidence at a second diffraction angle;
The light of the first color having the first angle of incidence is completely reflected, and the light of the second color having the second angle of incidence is transmitted. a first reflective layer;
a second reflective layer configured to completely reflect the second color light having the second incident angle;
The first reflective layer is between the first diffractive structure and the second diffractive structure, and the second diffractive structure is between the first reflective layer and the second reflective layer. In between is an optical device. The optical device further comprises a color-selective polarizer between the first diffractive structure and the second diffractive structure, wherein the first diffractive structure is: i) incident at the first angle of incidence; diffracting the first color light in a first polarization state with a first diffraction efficiency; ii) the second color light in a second polarization state incident at the second angle of incidence; with a diffraction efficiency that is substantially lower than the first diffraction efficiency, and the color-selective polarizer is configured to diffract the second color-selective polarizer that is incident on the color-selective polarizer. The second diffraction structure is configured to rotate the polarization state of the second color light in the polarization state from the second polarization state to the first polarization state, and the second diffraction structure configured to diffract the second color light in the first polarization state that is incident at an incident angle of at a second diffraction efficiency;
the optical device further comprising a side surface and a light absorber attached to the side surface and configured to absorb fully reflected light of the first color and the second color;
The first reflective layer allows the first color light having the first incident angle to reflect the second color light having the second incident angle without completely reflecting the first color light having the first incident angle. the first optical diffractive component directly adjacent the first reflective layer such that it is completely reflected by the interface between the reflective layer of the second optical diffractive component and the layer of the first optical diffractive component; configured to have a refractive index smaller than that of the layer;
The first optical diffractive component comprises a first carrier film and a first diffractive substrate attached to opposite sides of the first diffractive structure, the first carrier film the first carrier film is closer to the second diffractive structure than the substrate, the first carrier film comprises the first reflective layer, and the second optical diffractive component is closer to the second diffractive structure than the substrate; a second carrier film and a second diffractive substrate attached to both sides of the structure, the second diffractive substrate being closer to the first diffractive structure than the second carrier film; Optical device according to any one of claims 12 to 14, wherein it is advantageous that at least one of: a second reflective layer is attached to the second carrier film. a third diffractive structure configured to diffract first-order and zero-order third color light that is incident on the third diffractive structure at a third angle of incidence; further comprising a third optical diffractive component comprising: the first order is diffracted at a third angle of diffraction; the zero order is transmitted at the third angle of incidence; and the second reflective layer comprises: between the second diffraction structure and the third diffraction structure,
Optionally, each of the first reflective layer and the second reflective layer is configured to transmit light of the third color incident at the third angle of incidence;
Optionally, the optical device is a third reflective layer configured to completely reflect light of the third color incident on the third reflective layer at the third angle of incidence. further comprising a third reflective layer, wherein the third diffraction structure is between the second reflective layer and the third reflective layer,
Optionally, said second optical diffractive component comprises a second diffractive substrate and a second carrier film disposed on either side of said second diffractive structure, and said third optical diffractive component comprises a third carrier film and a third diffractive substrate positioned on both sides of the third diffractive structure, and the second reflective layer is arranged on both sides of the second carrier film and the third carrier film. The optical device according to any one of claims 12 to 15, which is between. each of the first diffractive structure and the second diffractive structure comprises a respective holographic grating formed on a recording medium;
Optionally, the recording medium comprises a photosensitive polymer;
Optionally, the recording medium is optically transparent;
Optionally, each of said first optical diffractive component and said second optical diffractive component comprises a respective Bragg grating formed in said recording medium, said respective Bragg grating comprising a plurality of fringes. a plurality of fringe planes that are planar and have a fringe inclination angle θ _t and a fringe spacing Λ perpendicular to the fringe plane within the volume of the recording medium;
Optionally, the respective Bragg gratings have a respective diffraction angle θ _m according to the Bragg equation mλ=2 n Λ sin (θ _m −θ _t ), where λ represents the respective wavelength of a certain color of light in vacuum, n represents the refractive index within the recording medium, and θ _m represents the wavelength of the recording medium. represents the mth diffraction order Bragg angle in the medium, θ _t represents the fringe tilt in the recording medium, and each of the first angle of incidence and the second angle of incidence is a respective on Bragg angle. and each of the first diffraction angle and the second diffraction angle is substantially the same as a respective primary Bragg angle;
Optionally, the thickness of the recording medium is more than an order of magnitude greater than the fringe spacing;
Optionally, the thickness of the recording medium is about 30 times greater than the fringe spacing;
Optionally, the first diffraction angle and the second diffraction angle are substantially the same as each other;
Optionally, each of the first diffraction angle and the second diffraction angle is in a range of -10 degrees to 10 degrees;
Optionally, each of the first diffraction angle and the second diffraction angle is substantially the same as 0 degrees;
Optical device according to any one of claims 12 to 16, optionally each of the first and second diffraction angles being substantially the same as 6 degrees. the first angle of incidence is different from the second angle of incidence,
Optionally, the first color of light has a smaller wavelength than the second color of light, and the first angle of incidence of the first color of light is such that the first color of light has a smaller wavelength than the second color of light. greater than the second angle of incidence of light;
Optical device according to any one of claims 12 to 17, wherein optionally each of the first angle of incidence and the second angle of incidence is in the range from 70 degrees to 90 degrees. a plurality of components including the first optical diffraction component and the second optical diffraction component, wherein two adjacent components of the plurality of components include an index matching material, OCA, UV attached together by an intermediate layer comprising at least one of a cured optical adhesive or a thermoset optical adhesive, or an optical contact material;
Optical device according to any one of claims 12 to 18, optionally wherein the second reflective layer comprises the intermediate layer. further comprising a substrate having a back surface attached to the front surface of the first optical diffractive component;
Optionally, the substrate has a side surface angled relative to the back surface and is configured to receive a plurality of different colors of light at the side surface;
Optionally, the angle between the side surface and the back surface of the substrate is 90 degrees or more,
Optionally, the substrate is configured such that the plurality of different colored lights are incident on the side surface at an angle of incidence substantially equal to 0 degrees;
Optionally, the substrate is wedge-shaped and comprises an inclined front surface, and the angle between the front surface and the side surface is less than 90 degrees. optical device. A system,
an illuminator configured to provide a plurality of different colors of light;
An optical device according to any one of claims 1 to 20,
The optical device is disposed adjacent to the illuminator and receives the plurality of different colors of light from the illuminator and diffracts the plurality of different colors of light. The system is configured as follows. the optical device is configured to diffract the plurality of different colors of light at respective diffraction angles that are substantially the same as each other, and optionally each of the respective diffraction angles: - 22. The system of claim 21, in the range of 10 degrees to 10 degrees. further comprising a controller coupled to the illuminator and configured to control the illuminator to provide each of the plurality of different colors of light;
Optionally, the system further includes a display comprising a plurality of display elements, and the optical device is configured to diffract the plurality of colors of light with respect to the display;
Optionally, the controller is coupled to the display and configured to transmit a respective control signal to each of the plurality of display elements for modulation of at least one characteristic of the display element. It is configured,
Optionally, the controller obtains graphics data including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space; and for each of the plurality of primitives, the plurality of primitives of the display. determining an electromagnetic (EM) field contribution to each of the display elements of the plurality of display elements; and generating a sum of the EM field contributions from the plurality of primitives to the display element for each of the plurality of display elements; and generating, for each of the plurality of display elements, the respective control signal based on the sum of the EM field contributions to the display element. system described in. A system,
a display comprising a plurality of display elements;
An optical device according to any one of claims 1 to 20,
The system wherein the optical device is configured to diffract light of a plurality of different colors to the display. The optical device and the display are arranged along a direction, the optical device having a front surface and a back surface along the direction, and the display having a front surface and a back surface along the direction. , the front surface of the display is spaced apart from the back surface of the optical device;
Optionally, the front side of the display is spaced from the back side of the optical device by a gap;
Optionally, at least one of the front side of the display or the back side of the optical device is treated with an anti-reflection coating;
Optionally, the system further comprises a transparent protective layer on the back side of the optical device;
Optionally, the front side of the display and the back side of the optical device are attached together by an intermediate layer;
Optionally, the intermediate layer is configured such that each of the plurality of colors of light transmitted by the optical device at zero order is completely reflected at an interface between the intermediate layer and the layer of the optical device. configured to have a refractive index lower than the refractive index of the layer of the optical device, so as to
Optionally, the system further includes a cover on the front surface of the display, and the optical device is formed within a cover glass;
25. The system of claim 24, optionally wherein the optical device is configured to receive the plurality of colors of light at the front surface of the optical device. The optical device includes a substrate in front of the optical device and is configured to receive the plurality of colors of light from at least one side of the substrate,
Optionally, the optical device comprises at least one diffraction grating supported by the substrate and configured to diffract the plurality of different colors of light towards the display;
Optionally, the substrate comprises a container filled with a liquid having a lower refractive index than the recording medium of the grating;
Optionally, the substrate is wedge-shaped and has an inclined front surface;
Optionally, the angle between the front surface and the side surface is less than 90 degrees;
Optionally, the optical device receives different portions of the plurality of different colored lights along different optical paths within the substrate and diffracts the different portions to produce different corresponding areas of the display. is configured to irradiate and to
Optionally, the different areas comprise two or more of a bottom area, a top area, a left area, and a right area of the display;
Optionally, the different portions of the plurality of different colored lights are provided by different corresponding illuminators;
Optionally, the optical device is configured to receive different portions of the plurality of different colored lights from different corresponding sides of the substrate;
Optionally, the optical device receives a first portion of the plurality of different colors of light from a first side of the substrate to the back side of the optical device and diffracts the first portion. irradiating a first region of the display and receiving a second portion of the plurality of different colored lights from a second side of the substrate to the front surface of the optical device; reflecting a second portion back against the back surface of the optical device and diffracting the second portion to illuminate a second region of the display. ,
Optionally, the first side and the second side are the same side,
Optionally, the second portion of the plurality of different colors of light is reflected by total internal reflection or a reflective grating within the optical device;
26. A system according to claim 24 or 25, wherein the substrate optionally comprises a partially reflective surface configured to separate input light into the first part and the second part. the optical device comprises at least one diffraction grating disposed on the back side of the optical device;
Optionally, said diffraction grating comprises different sub-regions with different corresponding diffraction efficiencies;
Optionally, the diffraction grating diffracts a first portion of the plurality of different colored lights incident on a first sub-region of the diffraction grating to illuminate a first region of the display; further directing a second portion of the plurality of different colored lights onto the front surface of the optical device that is reflected back against the back surface of the optical device and impinges on a second sub-region of the diffraction grating. and diffracting the second portion to illuminate a second different area of the display;
Optionally, the diffraction grating is configured such that the diffracted first portion and the diffracted second portion on the first region and the second region of the display have substantially the same optical It is constructed to have power,
Optionally, the first region and the second region of the display have a first different diffraction efficiency and a second different diffraction efficiency of the first sub-region and the second sub-region of the diffraction grating. A system according to any one of claims 24 to 26, having different reflectivities associated with different diffraction efficiencies. the diffraction grating comprises a plurality of sub-regions tiled together;
Optionally, the sub-region is tiled along a horizontal direction;
Optionally, edges of said different sub-regions are configured to abut each other in an optically seamless manner;
Optionally, the different sub-areas are formed by including one or more edge-defining elements in the optical path of at least one of the recording beam or the object beam when recording each sub-area on the recording medium. the one or more edge-defining elements comprising a square aperture, a rectangular aperture, or a planar tile aperture;
Optionally, two adjacent sub-regions of the grating abut a gap;
Optionally, the display comprises a plurality of tiled display devices, and the gaps between the adjacent sub-regions of the grating are aligned with the gaps between adjacent tiled display devices of the display. Ori,
28. The system of claim 27, optionally, two adjacent different sub-regions have an overlap. the diffraction grating is mechanically formed by using embossed, nanoimprinted, or self-assembled structures; and the display has a width along a horizontal direction; a height along a vertical direction, both the horizontal direction and the vertical direction are perpendicular to the direction, and an aspect ratio of the width to the height is greater than 16:9; 29. A system according to claim 27 or 28, wherein at least one is enabled. the optical device is configured to diffract the plurality of different colors of light at respective diffraction angles that are substantially the same as each other;
Optionally, each of said respective diffraction angles is in a range of -10 degrees to 10 degrees;
Optionally, the display is configured to diffract the diffracted colored light back through the optical device;
30. A system according to any one of claims 24 to 29, optionally wherein an area of the optical device covers an area of the display. further comprising an illuminator disposed adjacent to the optical device and configured to provide the plurality of colors of light to the optical device;
Optionally, the illuminator comprises a plurality of light emitting elements, each light emitting element configured to emit a respective color of light;
Optionally, the centers of the beams from the plurality of light emitting elements are offset with respect to each other;
Optionally, the illuminator is configured to provide a light beam with an elliptical beam profile or a rectangular beam profile;
Optionally, the illuminator is configured to provide a light beam with a particular polarization orientation;
Optionally, the illuminator comprises one or more optical components configured to independently control the ellipticity and polarization orientation of each of the plurality of different colored lights;
Optionally, the illuminator comprises one or more optical components configured to control the uniformity of the plurality of different colors of light;
Optionally, the one or more optical components comprise an apodizing optical element or a profile converter;
Optionally, the system comprises one or more anamorphic optical elements or one or more cylindrical optical elements configured to increase the width of the plurality of different colors of light. The system according to any one of the following. a prismatic element between the illuminator and the optical device, the prismatic element configured to receive the plurality of different colors of light from an input surface of the prismatic element;
one or more expansion gratings adjacent an exit face of the prismatic element, each of the one or more expansion gratings expanding a beam profile of light of a different corresponding color by a factor in at least one dimension; one or more expanded gratings configured to
Optionally, the system further includes one or more reflectors downstream of the one or more expanded gratings, each of the one or more reflectors directing a respective color of light to the optical device. It is designed to reflect
Optionally, the tilt angle of each of the one or more reflectors is independently adjustable to cause uniformity of diffraction from the optical device to the display;
Optionally, the system further comprises at least one of a color sensor or a brightness sensor configured to detect one or more optical properties of the holographic light field formed by the system; the tilt angle of one or more reflectors is adjustable based on the detected optical property of the holographic light field;
Optionally, the one or more optical properties include brightness uniformity, color uniformity, or white point;
Optionally, the one or more reflectors are adjustable to compensate for changes in alignment of components of the system;
Optionally, the optical distance between the one or more reflectors and the optical device is such that each of the plurality of different colors of light corresponds without transmission through one or more other reflectors. is configured to be reflected by a reflector that
Optionally, the one or more reflectors are configured such that light emitted by each of the one or more reflectors comes from substantially different directions;
Optionally, the angle between the prismatic element and the substrate of the optical device is adjustable to tilt the position of the holographic light field formed by the system;
32. The system of claim 31, wherein the one or more expansion gratings are configured to at least partially collimate the plurality of different colored light in one or two lateral directions. . further comprising a controller coupled to the illuminator and configured to control the illuminator to provide each of the plurality of colors of light;
Optionally, the controller is coupled to the display and configured to transmit a respective control signal to each of the plurality of display elements for modulation of at least one characteristic of the display element. has been
Optionally, the controller obtains graphics data including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space; and for each of the plurality of primitives, the plurality of primitives of the display. determining an electromagnetic (EM) field contribution to each of the display elements of the plurality of display elements; and generating a sum of the EM field contributions from the plurality of primitives to the display element for each of the plurality of display elements; generating, for each of the plurality of display elements, the respective control signal based on the sum of the EM field contributions to the display element;
Optionally, the controller sequentially modulates the display with information associated with the plurality of colors of light for a series of time periods, and wherein each of the plurality of colors of light is modulated by the optical device into the display. of each of said series of time periods so as to be diffracted against and reflected by a modulated display element of said display to form a respective color three-dimensional light field corresponding to said object within said respective time period. controlling the illuminator to sequentially emit each of the plurality of colors of light to the optical device during a period;
Optionally, the controller is configured such that the respective color three-dimensional light fields are: i) completely in front of the display, ii) completely behind the display, or iii) partially in front of the display. 33. The system of claim 31 or 32, wherein the system is configured to modulate the display so that it appears, and partially behind the display. the display comprises a spatial light modulator (SLM) including a digital micromirror device (DMD) or a liquid crystal on silicon (LCOS) device;
Optionally, the system further includes an optical polarizer disposed between the display and the optical device, the optical polarizer changing the polarization state of the plurality of different colors of light. A system according to any one of claims 24 to 33, wherein the system is configured. Optical diffraction, wherein the optical device is configured to diffract light comprising the plurality of different colors of light relative to the display, the optical device being configured to diffract a portion of the light illuminating the display element. Equipped with constituent elements,
Optionally, the optical device transmits the portion of the light to form a holographic scene and displays zero order light away from the holographic scene in three-dimensional (3D) space. further comprising an optical redirection component configured to redirect the display zero-order light including reflected light from the display;
Optionally, the optical redirection component comprises a plurality of redirecting holographic gratings for the display zero-order light of the plurality of different colors of light, each of the plurality of redirecting holographic gratings having a plurality of different colors of light. the display is configured to diffract the zero-order light of each of the colored lights toward a respective direction in the 3D space at a respective diffraction angle;
Optionally, the optical diffractive component redirects the display zero order light reflected from the display away from the holographic scene. configured to diffract colored light to illuminate the display at an angle of about 0 ^° ;
Optionally, the amount of the display zero order light in the holographic scene with suppression of the optical diffraction component and the optical redirection component and the display in the holographic scene without the suppression. The ratio to the amount of zero-order light is less than 2%,
Optionally, the optical redirection component comprises a one-dimensional suppression grating, the holographic scene includes a band corresponding to suppression of the display zero-order light, and the system is configured such that the band corresponds to suppression of the display zero-order light. System according to any one of claims 24 to 34, configured to be external. A system,
a display comprising a plurality of display elements;
an optical device disposed adjacent to the display and configured to diffract light with respect to the display;
obtaining graphic data coupled to the display and including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space;
determining the EM field contribution to each of the plurality of display elements of the display by calculating, for each of the plurality of primitives, electromagnetic (EM) field propagation from the primitive to the display element in a three-dimensional coordinate system; to judge and
for each of the plurality of display elements, generating the sum of the EM field contributions from the plurality of primitives to the display element;
transmitting a respective control signal for each of the plurality of display elements based on the sum of the EM field contributions to the display element for modulation of at least one characteristic of the display element; A system, including a controller configured to perform. The optical device includes the optical device according to any one of claims 1 to 11, and the optical device includes the optical device according to any one of claims 12 to 20. 37. The system of claim 36, wherein at least one of the: the optical device comprises a holographic grating formed on a recording medium;
The optical device comprises a plurality of holographic gratings formed on a recording medium, each of the plurality of holographic gratings emitting light of a respective color having a respective angle of incidence with respect to the display. be configured to diffract
the optical device is disposed in front of the display, the display diffracting the diffracted light back through the optical device to form a three-dimensional light field corresponding to the object; and the optical device further comprises an illuminator disposed adjacent the optical device and configured to provide the light to the optical device. 38. The system of claim 36 or 37, wherein one is enabled. The controller,
sequentially modulating the display with information associated with a plurality of colors corresponding to a plurality of colors of light during a series of time periods;
The illuminator is controlled to cause each of the plurality of colors of light to be diffracted by the optical device to the display and reflected by a modulated display element of the display to cause the plurality of colors of light to be diffracted by the optical device and reflected by a modulated display element of the display to sequentially emitting each of the plurality of colors of light to the optical device within each of the series of time periods to form a respective color three-dimensional light field corresponding to an object; 39. The system of claim 38, wherein the system is configured to. A method,
A method comprising making an optical device according to any one of claims 1 to 20. A method for producing an optical device according to any one of claims 1 to 11, comprising:
forming the first optical diffractive component;
forming the second optical diffractive component;
disposing the color selective polarizer between the first optical diffractive component and the second optical diffractive component. forming the first optical diffractive component includes forming a first diffractive structure in a recording medium;
Optionally, forming the first diffractive structure on the recording medium comprises directing a first recording object beam onto the recording medium at a first recording object angle and at a first recording reference angle. recording a first holographic grating on the recording medium by irradiating a first recording reference beam, the first recording object beam and the first recording reference beam having the same wavelength and have the same first polarization state,
Optionally, the first color of light comprises a wider or the same wavelength range as the first recording reference beam or the first recording object beam;
Optionally, the first recording reference beam corresponds to a different color from the first color of the first color of light;
Optionally, the first angle of incidence of the first color of light is substantially the same as the first recording reference angle, and the first angle of diffraction is substantially the same as the first recording reference angle. substantially the same as the angle,
Optionally, the first recording reference angle is in a range of 70 degrees to 90 degrees;
Optionally, the first recording reference angle is in a range of 80 degrees to 90 degrees,
Optionally, the first recording object angle is in the range -10 degrees to 10 degrees;
Optionally, the first recording object angle is substantially equal to 6 degrees;
Optionally, the first recording object angle is substantially the same as 0 degrees;
Optionally, the sum of the first recording reference angle and the first recording object angle is substantially equal to 90 degrees;
Optionally, the thickness of the recording medium is more than an order of magnitude greater than the wavelength of the first recording object beam;
Optionally, the thickness of the recording medium is about 30 times greater than the wavelength of the first recording object beam;
Optionally, forming the first diffractive structure on the recording medium includes fixing the first diffractive structure to the recording medium, and optionally, the recording medium is a carrier film. and the diffraction substrate,
Optionally, the first diffraction angle and the second diffraction angle are substantially the same as each other;
42. The method of claim 41, optionally, the first diffraction angle and the second diffraction angle are substantially the same as each other. disposing the color selective polarizer between the first optical diffractive component and the second optical diffractive component;
the first optical diffractive component such that the first color of light and the second color of light are incident on the first optical diffractive component before the second optical diffractive component; , the color-selective polarizer, and the second optical diffractive component;
Optionally, sequentially stacking the first optical diffractive component, the color-selective polarizer, and the second optical diffractive component comprises: sequentially disposing a polarizer and the second optical diffractive component on the substrate in front of the first optical diffractive component;
Optionally, sequentially laminating the first optical diffractive component, the color-selective polarizer, and the second optical diffractive component comprises combining the color-selective polarizer with a first intermediate layer. and attaching the second optical diffractive component to the color-selective polarizer through a second interlayer. 43. The method of claim 42, wherein each of the first interlayer and the second interlayer comprises a respective index matching material. forming a third optical diffractive component configured to diffract light of a third color having the first polarization state and a third angle of incidence at a third diffraction angle with a third diffraction efficiency; to do and
a second color-selective polarizer disposed between the second optical diffractive component and the third optical diffractive component, the second color-selective polarizer comprising: configured to rotate a polarization state of a third color of light from the second polarization state to the first polarization state;
Optionally, the color selective polarizer is configured to rotate the polarization state of the first color light from the first polarization state to the second polarization state, and the color selective polarizer is configured to rotate the polarization state of the first color light from the first polarization state to the second polarization state, a color-selective polarizer that changes the polarization state of the second color light from the first polarization state to the second polarization state without rotation of the polarization state of the first color light. It is configured to rotate to the state
Optionally, the method includes a third color-selective polarizer in sequence with the third optical diffractive component, and the third optical diffractive component is in series with the second color-selective polarizer. and the third color-selective polarizer, the third color-selective polarizer rotating the polarization state of the third color of light. the polarization state of each of the first color light and the second color light is rotated from the second polarization state to the first polarization state;
Optionally, the method includes a fourth color-selective polarizer before the first optical diffractive component, and a fourth color-selective polarizer and the first optical diffractive component. and a color-selective polarizer, the fourth color-selective polarizer disposed between each of the second color light and the third color light. The polarization state of the first color light is configured to be rotated from the second polarization state to the first polarization state without rotating the polarization state. The method described in any one of the above. 45. A method according to any one of claims 41 to 44, wherein the first polarization state is s-polarization and the second polarization state is p-polarization. A method for producing an optical device according to any one of claims 12 to 20, comprising:
forming the first optical diffractive component comprising the first diffractive structure;
forming the second optical diffractive component comprising the second diffractive structure;
arranging the first reflective layer between the first diffractive structure and the second diffractive structure, wherein the second diffractive structure overlaps the first diffractive structure along a certain direction; to be continuous with, to place;
arranging the second reflective layer in succession to the second diffractive structure along the direction. further comprising forming a light absorber on a side surface of the optical device, the light absorber configured to absorb the fully reflected light of the first color and the second color. and
Optionally, the first reflective layer causes the first color of light having the first angle of incidence to fully reflect the second color of light having the second angle of incidence. the first reflective layer directly adjacent to the first reflective layer such that it is completely reflected by the interface between the first reflective layer and the layer of the first optical diffractive component without is configured to have a refractive index that is less than the layer of optical diffractive components of the
Optionally, the method further comprises forming a third optical diffractive component comprising a third diffractive structure configured to diffract light of a third color having a third angle of incidence. and disposing the second reflective layer consecutively to the second diffractive structure along the direction, between the second diffractive structure and the third diffractive structure along the direction. arranging the second reflective layer at a position where each of the first reflective layer and the second reflective layer transmits light of the third color having the third incident angle. It is composed of
Optionally, the method further comprises arranging a third reflective layer in succession to the third diffractive structure along the direction, the third reflective layer being configured to completely reflect the third color light having corners,
Optionally, each of said first optical diffractive component, said second optical diffractive component, and said third optical diffractive component comprises a respective carrier film and a respective diffractive substrate; one reflective layer comprising a first carrier film of the first optical diffractive component, and locating the first reflective layer between the first diffractive structure and the second diffractive structure. attaching a second diffractive substrate of the second optical diffractive component to the first carrier film of the first optical diffractive component by a first intermediate layer, arranging the second reflective layer between the second diffractive structure and the third diffractive structure, the second intermediate layer comprising the second carrier film of the second optical diffractive component; attaching to a third carrier film of a third optical diffractive component, the second reflective layer comprising the second intermediate layer, the third reflective layer comprising the third optical diffractive component; 47. The method of claim 46, wherein the element is attached to a third diffractive substrate. arranging the first optical diffractive component on a substrate in front of the first optical diffractive component along the direction, the substrate comprising a front surface and a back surface; Furthermore, it includes
Optionally, arranging the first optical diffractive component on the substrate includes attaching a front surface of the first optical diffractive component to the back surface of the substrate through an index matching material. including;
Optionally, the substrate comprises a side surface that is angled relative to the back surface of the substrate, and the substrate is configured to receive a plurality of different colors of light at the side surface;
48. The method of claim 47, wherein the substrate is optionally configured such that the plurality of different colored lights are incident on the side surface at an angle of incidence substantially the same as 0 degrees. forming the first optical diffractive component comprising the first diffractive structure includes forming the first diffractive structure on a recording medium;
Optionally, forming the first diffractive structure in the recording medium causes a first recording object beam at a first recording object angle and a first recording reference beam at a first recording reference angle. recording a first holographic grating on the recording medium by injecting a holographic grating into the recording medium, the first recording object beam and the first recording reference beam having the same wavelength and the same polarization state. death,
Optionally, the first color of light includes a wider or the same wavelength range as the first recording reference beam;
Optionally, the first recording reference beam corresponds to a different color from the first color of the first color of light;
Optionally, the first angle of incidence of the first color of light is substantially the same as the first recording reference angle, and the first angle of diffraction is substantially the same as the first recording reference angle. substantially the same as the angle,
Optionally, the first recording reference angle is in a range of 70 degrees to 90 degrees;
Optionally, the first recording reference angle is in a range of 70 degrees to 80 degrees;
Optionally, the first recording object angle is in the range -10 degrees to 10 degrees;
Optionally, the thickness of the recording medium is more than two orders of magnitude greater than the wavelength of the first recording object beam;
Optionally, the thickness of the recording medium is about 30 times greater than the wavelength of the first recording object beam;
49. Optionally, forming the first diffractive structure on the recording medium comprises fixing the first diffractive structure to the recording medium. the method of. the first angle of incidence is different from the second angle of incidence,
46. Optionally, the first color of light has a smaller wavelength than the second color of light and the first angle of incidence is greater than the second angle of incidence. 49. The method according to any one of items 49 to 49. A method,
Forming an optical device according to the method according to any one of claims 40 to 50;
arranging the optical device and a display comprising a plurality of display elements such that the optical device is configured to diffract a plurality of different colors of light onto the display; Method. Optionally, positioning the optical device and the display includes spacing a back side of the optical device from a front side of the display by a gap, and optionally the method includes separating the front side of the display or the optical further comprising forming an anti-reflective coating on at least one of the back surfaces of the device;
arranging the optical device and the display includes attaching a back side of the optical device onto the front side of the display through an intermediate layer, optionally the intermediate layer being less than the refractive index of the layers of the optical device such that each of the plurality of different colors of light transmitted in the zero order is completely reflected at the interface between the intermediate layer and the layer of the optical device. is also configured to have a low refractive index;
the optical device is configured to diffract the plurality of different colors of light at respective diffraction angles that are substantially the same as each other, and optionally each of the respective diffraction angles: - be in the range of 10 degrees to 10 degrees,
the display is configured to diffract the diffracted colored light back through the optical device;
an area of the optical device covers an area of the display; and the optical device comprises a substrate in front of the optical device, a side of the substrate being angled with respect to a back side of the substrate. 52. The method of claim 51, wherein at least one of: configured to receive the plurality of different colors of light at. A method,
using an optical device to convert an incident beam containing a plurality of different colors of light into individually diffracted colored lights;
A method, wherein the optical device comprises an optical device according to any one of claims 1 to 20. A method,
transmitting at least one timing control signal to the illuminator such that the optical device converts the plurality of different colors of light into individually diffracted colors of light to illuminate a display comprising a plurality of display elements; and actuating the illuminator to emit the plurality of different colored lights to the optical device, the optical device comprising an optical device according to any one of claims 1 to 20. preparing and releasing;
the plurality of display elements of the display such that the individually diffracted colored light is reflected by the modulated display elements to form a multicolored three-dimensional light field corresponding to the respective control signals; transmitting at least one respective control signal for each of the display elements to modulate the display element. obtaining graphic data including respective primitive data for a plurality of primitives corresponding to objects in three-dimensional space;
determining the EM field contribution to each of the plurality of display elements of the display by calculating, for each of the plurality of primitives, electromagnetic (EM) field propagation from the primitive to the display element in a three-dimensional coordinate system; to judge and
for each of the plurality of display elements, generating the sum of the EM field contributions from the plurality of primitives to the display element;
generating, for each of the plurality of display elements, the respective control signal based on the summation of the EM field contributions to the display element for modulation of at least one characteristic of the display element; further including;
the polychromatic three-dimensional light field corresponds to the object;
Optionally, the method sequentially modulates the display with information associated with the plurality of different colors for a series of time periods, and wherein each of the plurality of different colors of light is applied to the display by the optical device. each of said series of periods so as to be diffracted against and reflected by said modulated display element of said display to form a respective color three-dimensional light field corresponding to said object within said respective period; controlling the illuminator to sequentially emit each of the plurality of colors of light to the optical device within a period of time;
Optionally, the plurality of different colored lights are diffracted by the optical device at substantially the same diffraction angle with respect to the display;
Optionally, the diffraction angle is in the range -10 degrees to 10 degrees,
Optionally, the illuminator and the optical device are configured such that the plurality of different colors of light are incident on the first optical diffractive component of the optical device at respective angles of incidence. ,
Optionally, the respective incident angles are different from each other,
Optionally, the respective angles of incidence are substantially the same as each other;
55. The method of claim 54, wherein optionally each of said respective angles of incidence is in the range of 70 degrees to 90 degrees. An optical device,
at least two optical diffractive components;
at least one color selective polarizer;
The optical device is configured such that when light of different colors is incident on the optical device, the optical device separates individual colored lights of the different colors while suppressing crosstalk between the different colors. An optical device consisting of: the optical device is configured such that each of the optical diffractive components diffracts a respective one of the different colors when the different colors of light are incident on the optical device;
Optionally, the optical device is configured such that in an output light beam diffracted by the optical device, the power of light of a particular color of the different colors is such that the power of light of a particular color of the different colors is greater than that of one or more other of the different colors. The power of the light is at least one order of magnitude higher than that of the
Optionally, said at least one color-selective polarizer is configured such that light of a particular color of said different colors is incident on a respective one of said optical diffractive components in a first polarization state. , such that light of one or more of the different colors is incident on a respective one of the optical diffractive components in a second polarization state different from the first polarization state; 57. The optical device of claim 56, configured to rotate the polarization state of light of at least one of the different colors. An optical device,
at least two optical diffractive components;
at least one reflective layer;
The optical device is configured such that when light of different colors is incident on the optical device, the optical device separates individual colored lights of the different colors while suppressing crosstalk between the different colors. It is configured,
The optical device, wherein the at least one reflective layer is configured for total internal reflection of light of at least one of the different colors. The optical device is arranged such that the output light beam diffracted by the optical device is configured to provide light of a particular color among the different colors without crosstalk from one or more other colors of the different colors. It is configured to contain only
Optionally, said at least one reflective layer completely reflects zero-order light of a particular color of said different colors transmitted by a respective one of said optical diffractive components, while configured to transmit one or more other colors;
Optionally, the optical device is configured such that each of the optical diffractive components diffracts a respective color of light of the different colors when the different colors of light are incident on the optical device. 59. The optical device of claim 58. A system,
display and
An optical device according to any one of claims 56 to 59,
The system wherein the optical device is configured to diffract light of a plurality of different colors to the display. A system,
an illuminator configured to provide a plurality of different colors of light;
An optical device according to any one of claims 56 to 59,
The system, wherein the optical device is configured to diffract the plurality of different colors of light from the illuminator. A system,
display and
an optical device comprising one or more transmissive diffractive structures for diffracting light to the display. the display is a reflective display configured to diffract the light back through the optical device;
Optionally, the system further comprises an illuminator configured to provide the light to the optical device, the illuminator being positioned in front of the transmissive diffractive structure of the optical device. 63. The system of claim 62. the display is a transmissive display configured to diffract the light forward without passing through the optical device;
Optionally, the system further comprises an illuminator configured to provide the light to the optical device, the illuminator being positioned behind the transmissive diffractive structure of the optical device. 63. The system of claim 62. each of the one or more transmissive diffractive structures is configured to diffract a respective one of a plurality of different colors, and the optical device further comprises one or more reflective diffractive structures, and the optical device further comprises one or more reflective diffractive structures; At least one of the following is effective: each of the one or more transmission diffraction structures and the one or more reflection diffraction structures are configured to diffract a respective one of a plurality of different colors. 65. The system according to any one of 62 to 64. A system,
display and
an optical device comprising one or more reflective diffractive structures for diffracting light to the display. the display is a reflective display configured to diffract the light back through the optical device;
Optionally, the system further comprises an illuminator configured to provide the light to the optical device, the illuminator being positioned behind the reflective diffractive structure of the optical device. 67. The system of claim 66. the display is a transmissive display configured to diffract the light forward without passing through the optical device;
Optionally, the system further comprises an illuminator configured to provide the light to the optical device, the illuminator being positioned in front of the reflective diffractive structure of the optical device. 67. The system of claim 66. each of the one or more reflective diffractive structures is configured to diffract a respective one of a plurality of different colors; and the optical device further comprises one or more transmissive diffractive structures; At least one of the following is effective: each of the one or more transmission diffraction structures and the one or more reflection diffraction structures are configured to diffract a respective one of a plurality of different colors. 69. The system according to any one of 66 to 68. An optical device,
comprising a plurality of optical diffractive components comprising at least one transmissive diffractive structure and at least one reflective diffractive structure;
the optical device is configured to separate individual colored lights of the different colors while suppressing crosstalk between the different colors when the different colored lights are incident on the optical device; optical device. Each of the transmission diffraction structure and the reflection diffraction structure is configured to diffract light of each of the different colors,
Optionally, the optical device further comprises at least one reflective layer configured for total internal reflection of light of at least one of the different colors;
Optionally, the optical device is configured such that light of a particular one of the different colors is incident on a respective one of the optical diffractive components in a first polarization state; of said different colors such that light of one or more other colors of said is incident on each one of said optical diffractive components in a second polarization state different from said first polarization state. 71. The optical device of claim 70, further comprising at least one color-selective polarizer configured to rotate the polarization state of at least one color of light. A system,
display and
An optical device according to claim 70 or claim 71,
The system wherein the optical device is configured to diffract light of a plurality of different colors onto the display. A system,
an illuminator configured to provide a plurality of different colors of light;
An optical device according to claim 70 or claim 71,
The system, wherein the optical device is configured to diffract the plurality of different colors of light from the illuminator. An optical device,
configured to expand the input light beam in at least two dimensions to produce the output light beam by diffracting the input light beam and adjusting the beam size of the input light beam in at least two dimensions; 1. An optical device comprising at least two beam expanders. the beam size includes width and height;
Optionally, each of said at least two beam expanders comprises a respective optical diffraction device;
Optionally, the input light beam includes a plurality of different colors of light, and the respective optical diffraction devices diffract the plurality of different colors of light at respective diffraction angles that are substantially the same as each other. It is configured as follows.
Optionally, the respective optical diffraction devices are configured to suppress crosstalk between the different colors when the light of the different colors is incident on the respective optical diffraction devices. while being configured to separate the individual colored lights of the different colors;
Optionally, each optical diffractive device comprises at least two optical diffractive components and at least one color selective polarizer;
Optionally, said each optical diffractive device comprises at least two optical diffractive components and at least one reflective layer, said at least one reflective layer for total internal reflection of at least one color of light. It is composed of
75. The optical device of claim 74, optionally, said respective optical diffractive device comprising at least one of one or more transmissive diffractive structures or one or more reflective diffractive structures. the at least two beam expanders,
a first one-dimensional beam expander configured to expand the input light beam of a first of the at least two dimensions to produce an intermediate light beam;
a second one-dimensional beam expander configured to expand the intermediate light beam in a second of the at least two dimensions to produce the output light beam;
the intermediate light beam has a larger beam size than the input light beam of the first dimension and the same beam size as the input light beam of the second dimension; a beam size larger than the intermediate light beam of dimensions , and the same beam size as the intermediate light beam of the first dimension;
Optionally, the optical device uses at least one of a free-space aerial geometry, a monolithic or segmented substrate, or one or more coupling elements to direct the intermediate light beam to the first configured to couple from the first one-dimensional beam expander to the second one-dimensional beam expander;
Optionally, said intermediate input beam comprises collinearly collimated light of two or more colors, and said one or more coupling elements comprises said collinearly collimated light of said two or more colors. 75 or 80, wherein the light beam is configured to convert the light into two or more independent collimated but non-collinear light beams having corresponding colors of the two or more colors. 75. The optical device according to 75.