CN112596281A - Spatial light modulator and method for manufacturing the same - Google Patents

Abstract

The invention discloses a spatial light modulator, comprising: a reflection layer for reflecting incident waves; a modulation layer arranged on the reflection layer, the optical properties of the modulation layer can be adjusted, including a pixel modulation unit; An electrode layer, arranged on the modulation layer, includes a modulation electrode, the modulation electrode is arranged on the pixel modulation unit, and the modulation electrode changes the optical properties of the modulation layer by changing the voltage applied to the pixel modulation unit , has the characteristics of high stability, high robustness, long service life and high modulation speed. The invention also discloses a preparation method of the spatial light modulator. By using the modulation electrode to change the voltage of the pixel modulation unit, the optical properties of the modulation layer are changed, thereby realizing the modulation of the light wave. Compared with the liquid crystal spatial light modulator, the The invention has the beneficial effects of few processing steps, low processing difficulty, high yield and low production cost.

Description

Spatial light modulator and method of making the same

technical field

The invention relates to the field of optics, in particular to a spatial light modulator and a preparation method thereof.

Background technique

Optical information processing technology is based on optical devices, uses light waves to carry information, and processes information in a parallel manner. It has the advantages of large information capacity and fast information processing speed. It has important application value in the rapidly developing information age. Sensors, optical computers, and digital holographic imaging play an important role.

Spatial light modulator is an important optical device in optical information processing system. It has multiple pixel units and can adjust optical parameters such as amplitude and phase of light waves, so that optical parameters can form one-dimensional or two-dimensional distribution in space. At present, the main types of spatial light modulators are liquid crystal spatial light modulators. The main functional material of the liquid crystal spatial light modulator is liquid crystal, and it also includes a guide layer and a sealant. The connection structure such as the frame sealant is easy to move, and there is a problem of weak fixing stability. The use temperature of liquid crystal is usually not more than 50 ℃. Liquid crystal, guide layer and frame sealant are all organic compounds with low temperature stability. They are easy to age when used under light and high temperature, and have the problems of low use temperature and short service life. The modulation mechanism of the liquid crystal spatial light modulator usually adopts the electro-birefringence effect of liquid crystal. Due to the limitation of the minimum uniformity of the liquid crystal material, the thickness of the liquid crystal layer and the minimum thickness of the liquid crystal layer, the liquid crystal spatial light modulator has the disadvantage of low modulation speed. The modulation speed is usually on the order of one hundred Hertz.

Since the liquid crystal spatial light modulator contains many structural parts, the preparation method of the liquid crystal spatial light modulator has the disadvantages of many processing steps, high processing difficulty, high production cost and low yield. The preparation steps of the liquid crystal spatial light modulator generally include the preparation steps of silicon-based complementary metal oxide semiconductor integrated circuits and the steps of laminating and packaging the liquid crystal panel. The preparation steps of silicon-based complementary metal oxide semiconductor integrated circuits usually include the first deposition of silicon oxide, the first patterning, ion implantation, the removal of remaining silicon oxide, the second deposition of silicon oxide, the deposition of silicon nitride, the second Patterning, the third deposition of silicon oxide, the deposition of silicon nitride, the third patterning, and the preparation of contact holes, gates and electrodes, etc., including 19 steps including 9 depositions, 3 ion implantations, and 7 patterning , the yield is 90%. The steps of laminating and encapsulating the liquid crystal panel include five steps, including preparing the guide layer, exposing the guide layer, coating the sealant, pouring the liquid crystal and coating the sealant, and the yield is 30%. Therefore, there are 24 preparation steps for the liquid crystal spatial light modulator, the yield is 27%, the yield is low, and the production cost is high. Among them, the number of patterns is large, the alignment deviation is large, the preparation of the contact hole is difficult, and the alignment deviation of the coating sealant is large, so the processing of the liquid crystal spatial light modulator is difficult.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, reduce the processing difficulty of the spatial light modulator, and improve the yield of the spatial light modulator, the present invention discloses a spatial light modulator and a preparation method thereof. The specific solutions are as follows.

A spatial light modulator, comprising:

Reflective layer for reflecting incident waves;

a modulation layer, disposed on the reflective layer, the optical properties of the modulation layer can be adjusted, including a pixel modulation unit;

An electrode layer, arranged on the modulation layer, includes a modulation electrode, the modulation electrode is arranged on the pixel modulation unit, and the modulation electrode changes the optical properties of the modulation layer by changing the voltage applied to the pixel modulation unit .

According to some embodiments of the present invention, the number of the modulation electrodes is multiple, and a plurality of the modulation electrodes are arranged on the electrode layer in an array.

According to some embodiments of the present invention, the reflective layer includes at least two layers, each of which has a different refractive index; the material of the reflective layer includes one of the following: a conductor, a semiconductor, or an insulator.

According to some embodiments of the present invention, the number of layers of the reflective layer is an even number of layers, the material of the layers with an odd number of layers is SiO ₂ , the thickness is a positive integer multiple of 240 nm, and the refractive index is 1.5; the number of layers is numbered as The material of the even-numbered layers is Ta ₂ O ₅ , the thickness is a positive integer multiple of 190 nm, and the refractive index is 2.0.

According to some embodiments of the present invention, the material of the modulation layer includes one of the following: a thermo-optic material, an electro-optic material, an acousto-optic material or a magneto-optic material.

According to some embodiments of the present invention, the electrode layer further includes:

The common electrode pad is connected to the modulation electrode through the lead-out electrode;

a pixel electrode pad, connected to the modulation electrode through an extraction electrode;

Wherein, the common electrode pad is connected to the negative pole of the external power supply, and the pixel electrode pad is connected to the positive pole of the external power supply; or,

The common electrode pad is connected to the positive pole of the external power supply, and the pixel electrode pad is connected to the negative pole of the external power supply.

According to some embodiments of the present invention, the material of the electrode layer includes one or a combination of the following: metal, alloy and transparent conductive oxide.

A preparation method of a spatial light modulator, comprising:

preparing a reflective layer on the substrate layer;

preparing a modulation layer on the reflective layer, and patterning the modulation layer to prepare a pixel modulation unit;

preparing an electrode layer on the modulation layer, and patterning the electrode layer to prepare modulation electrodes, lead-out electrodes, common electrode pads and pixel electrode pads;

preparing an insulating layer on the electrode layer, and patterning the insulating layer;

Wherein, the modulation electrode is arranged on the pixel modulation unit, the common electrode pad is connected to the negative electrode of the external power supply, and the pixel electrode pad is connected to the positive electrode of the external power supply; or,

The common electrode pad is connected to the positive pole of the external power supply, and the pixel electrode pad is connected to the negative pole of the external power supply.

According to some embodiments of the present invention, before patterning the modulation layer, the method further includes: thinning and polishing the lower surface of the modulation layer, and forming the upper surface of the reflective layer and the lower surface of the modulation layer Bonding is performed.

According to some embodiments of the present invention, the preparation of the reflective layer, the preparation of the modulation layer, the preparation of the electrode layer, and the preparation of the insulating layer include a physical method or a chemical method; the physical method includes one of the following: magnetron sputtering spraying method, ion beam sputtering method, electron beam evaporation method, thermal evaporation method or molecular beam epitaxy method; the chemical method includes one of the following: chemical vapor deposition method, electrochemical method, sol-gel method or hydrothermal method.

Through the above technical solution, the optical properties of the modulation layer are changed by changing the voltage of the pixel modulation unit by using the modulation electrode, thereby realizing the modulation of the light wave. Compared with the liquid crystal spatial light modulator, at the same time, because the use of inorganic substances As a solid state reflection layer, modulation layer, electrode layer and insulating layer, it has the characteristics of high stability, high robustness, long service life and high modulation speed.

Description of drawings

FIG. 1 schematically shows a schematic structural diagram of a spatial light modulator according to an embodiment of the present invention;

FIG. 2 schematically shows a schematic structural diagram of a spatial light modulator according to another embodiment of the present invention;

3 schematically shows a schematic top view of a spatial light modulator according to an embodiment of the present invention;

FIG. 4 schematically shows a schematic top view of a spatial light modulator according to another embodiment of the present invention;

5 schematically shows a flow chart of a method for manufacturing a spatial light modulator according to an embodiment of the present invention;

Among them, 100 represents the substrate layer; 200 represents the reflective layer, 201-208 represent the odd and even layers of the reflective layer, respectively; 300 represents the modulation layer, 301 represents the pixel modulation unit; 400 represents the electrode layer, and 401 represents the common electrode pad , 402 represents the pixel electrode pad, 403 represents the lead-out electrode, 404 represents the modulation electrode; 500 represents the insulating layer.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

It should be understood, however, that these descriptions are exemplary only, and are not intended to limit the scope of the present invention. In the following detailed description, for convenience of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present invention. It will be apparent, however, that one or more embodiments may be practiced without these specific details. Also, in the following description, descriptions of well-known technologies are omitted to avoid unnecessarily obscuring the concepts of the present invention.

The terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the present invention. The term "comprising" as used herein indicates the presence of a feature, step, operation, but does not exclude the presence or addition of one or more other features.

All terms (including technical and scientific terms) used herein have the meaning as commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly rigid manner.

The purpose of the present invention is to provide a spatial light modulator and a preparation method thereof, by which the problems of weak fixation stability, low use temperature, short service life and low modulation speed can be solved by using the spatial light modulator. The preparation method of the modulator can solve the problems of many processing steps, high processing difficulty, low yield and high production cost.

In order to solve the above technical problems, the present invention discloses a spatial light modulator and a preparation method thereof. The specific solutions are as follows.

FIG. 1 schematically shows a schematic structural diagram of a spatial light modulator according to an embodiment of the present invention.

As shown in FIG. 1 , a spatial light modulator includes: a reflective layer 200 , a modulation layer 300 and an electrode layer 400 .

According to some embodiments of the present invention, the reflective layer 200 is used to reflect incident waves. Specifically, the light waves pass through the electrode layer 400 and the modulation layer 300 in sequence, are reflected at the reflective layer 200 , and then pass through the modulation layer 300 and the electrode in sequence. The layer 400 completes the modulation of the light wave.

According to some embodiments of the present invention, the reflective layer 200 includes at least two layers, each of which has a different refractive index; the material of the reflective layer 200 includes one of the following: a conductor, a semiconductor, or an insulator.

According to some embodiments of the present invention, the number of layers of the reflective layer 200 is an even number, the material of the layers with an odd number of layers is SiO ₂ , the thickness is a positive integer multiple of 240 nm, and the refractive index is 1.5; the number of layers is an even number The layered material is Ta ₂ O ₅ , the thickness is a positive integer multiple of 190 nm, and the refractive index is 2.0.

FIG. 2 schematically shows a schematic structural diagram of a spatial light modulator according to another embodiment of the present invention.

According to some embodiments of the present invention, as shown in FIG. 2 , optionally, the reflective layer 200 includes 8 layers.

The layers with odd numbers (eg: layer 201 , layer 203 , layer 205 and layer 207 ) are made of SiO ₂ , the thickness is a positive integer multiple of 240 nm, and the refractive index is 1.5.

The layers with even numbers (eg: layer 202 , layer 204 , layer 206 and layer 208 ) are made of Ta ₂ O ₅ , the thickness is a positive integer multiple of 190 nm, and the refractive index is 2.0.

With the above structure, the reflectivity of the reflective layer 200 at a wavelength of 1550 nm can be made to be 95%.

According to some embodiments of the present invention, the reflective layer 200 is composed of a layered interval of a high refractive index material and a low refractive index material, which can achieve higher reflectivity.

According to some embodiments of the present invention, the reflective layer 200 is located below the modulation layer 300 , and the reflective layer 200 has a high reflectivity, so the reflective layer 200 can reflect the light waves incident through the modulation layer 300 from above and back to the top, thereby The modulation of light waves is realized to form a reflective spatial light modulator.

According to some embodiments of the present invention, the thickness of the reflective layer 200 is 1 nm to 1 mm.

According to some embodiments of the present invention, the reflective layer 200 is conductor Al. The thickness of Al is 200 nm, and the reflectance at a wavelength of 1550 nm is 90%.

According to some embodiments of the present invention, the modulation layer 300 is disposed on the reflective layer 200 , and the optical properties of the modulation layer 300 can be adjusted, including the pixel modulation unit 301 .

According to some embodiments of the present invention, the optical properties of the modulation layer 300 can be adjusted, including refractive index or absorption coefficient.

According to some embodiments of the present invention, the shape of the pixel modulation unit 301 includes a cube, a rectangular parallelepiped, a cylinder or a trapezoidal pyramid.

According to some embodiments of the present invention, the number of pixel modulation units 301 is multiple, and a gap is provided between two adjacent pixel modulation units 301 .

According to some embodiments of the present invention, the material of the modulation layer 300 includes one of the following: a thermo-optic material, an electro-optic material, an acousto-optic material or a magneto-optic material.

According to some embodiments of the present invention, the modulation layer 300 is a conductor, a semiconductor or an insulator.

According to some embodiments of the present invention, the structure of the modulation layer 300 is a thin film structure, a nanostructure, a superlattice structure or a photonic crystal structure.

According to some embodiments of the present invention, the modulation layer 300 includes one of the following: Si, Ge, ITO, AZO, ZnO, GaN, AlN, ZnS, SiC, AlP, GaP, Au, _Ag , Pt, VO2, _LiNbO3 , LiTaO ₃ , BaTiO ₃ , Ta ₂ O ₅ or SiO ₂ .

According to some embodiments of the present invention, the thickness of the modulation layer 300 is 1 nm to 1 mm.

According to some embodiments of the present invention, optionally, the modulation layer 300 is BaTiO ₃ . _The thickness of BaTiO3 is 500 nm. BaTiO3 is an electro _- optic material with an electro-optic coefficient of 105pm/V and a refractive index of 2.1 at a wavelength of 1550nm. It can be understood that the modulation layer 300 is located below the electrode layer 400, and the modulation layer 300 has a large electro-optic coefficient, so applying a voltage to the modulation layer 300 through the electrode layer 400 can change the refractive index of the modulation layer 300, thereby changing the incident light The modulation of the light wave is realized by the optical path difference of the modulation layer.

According to some embodiments of the present invention, optionally, the modulation layer 300 is VO ₂ . _The thickness of VO2 is 100nm. VO2 is a thermo _- optic material with a refractive index of 2.1 at 1550nm wavelength. It can be understood that the modulation layer 300 is located below the electrode layer 400, so the heat generated by applying a voltage to the electrode layer 400 can change the temperature of the modulation layer 300, thereby changing the refractive index of the modulation layer 300, thereby changing the incident light passing through The optical path difference of the modulation layer 300 realizes modulation of light waves.

FIG. 3 schematically shows a schematic top view of a spatial light modulator according to an embodiment of the present invention; FIG. 4 schematically shows a top view of a spatial light modulator according to another embodiment of the present invention.

According to some embodiments of the present invention, which can be described with reference to FIG. 2 , as shown in FIG. 3 and FIG. 4 , the electrode layer 400 is provided on the modulation layer 300 , including the modulation electrode 404 , and the modulation electrode 404 is provided on the pixel modulation unit 301 , The modulation electrode 404 completes changing the optical properties of the modulation layer 300 by changing the voltage applied to the pixel modulation unit 301 .

According to some embodiments of the present invention, the number of modulation electrodes 404 is multiple, and the plurality of modulation electrodes 404 are arranged on the electrode layer in an array.

According to some embodiments of the present invention, the shape of the modulation electrode 404 includes a cube, a rectangular parallelepiped, a cylinder, or a trapezoidal pyramid.

According to some embodiments of the present invention, the shape of the modulation electrode 404 is consistent with the shape of the pixel modulation unit 301 .

According to some embodiments of the present invention, optionally, the electrode layer 400 is Au. The thickness of Au is 100 nm. The resistivity of Au material is 2.4×10 ^-8 Ω·m. The modulation electrode 404 has a length of 1 mm, a width of 1 μm, and a pitch of 1 mm.

According to some embodiments of the present invention, optionally, the length and width of the common electrode pad 401 are both 100 μm.

According to some embodiments of the present invention, optionally, the length and width of the pixel electrode pads 402 are both 100 μm, and the smaller spacing in the vertical direction is 10 μm.

According to some embodiments of the present invention, the width of the extraction electrode 403 is 1 μm, and the smaller distance between the extraction electrode and the modulation electrode in the vertical direction is 1 μm.

According to some embodiments of the present invention, the electrode layer has a total of 16 modulation electrodes 404 arranged in a 4*4 array. Correspondingly, each modulation electrode 404 corresponds to a pixel modulation unit 301 below. The number of common electrode pads 401 is one, and the common electrode pad 401 is used to connect the negative electrode of the external power supply, and is connected to one end of each modulation electrode 404 through the lead-out electrode 403 . The number of pixel electrode pads 402 is 16, and the pixel electrode pads 402 are used for connecting the positive electrode of the external power supply. It can be understood that the electrode layer 400 is located above the modulation layer 300, and the common electrode pad 401 and each pixel electrode pad 402 can independently control the voltage on each pixel modulation unit 301, thereby independently controlling the refractive index of the modulation layer 300 , and then realize the two-dimensional distribution of light waves in space.

According to some embodiments of the present invention, the electrode layer 400 further includes a common electrode pad 401 , an extraction electrode 403 and a pixel electrode pad 402 .

According to some embodiments of the present invention, gaps are provided between the common electrode pad 401 , the pixel electrode pad 402 , the extraction electrode 403 and the modulation electrode 404 .

According to some embodiments of the present invention, the thickness of the electrode layer 400 is 1 nm to 1 mm.

According to some embodiments of the present invention, the modulation electrode 404 has a length of 1 nm to 1 mm and a width of 1 nm to 1 mm.

According to some embodiments of the present invention, the length of the common electrode pad 401 is 1 nm to 1 mm, and the width is 1 nm to 1 mm.

According to some embodiments of the present invention, the pixel electrode pad 402 has a length of 1 nm to 1 mm and a width of 1 nm to 1 mm.

According to some embodiments of the present invention, the length of the extraction electrode 403 is 1 nm to 1 mm.

According to some embodiments of the present invention, the spacing between two adjacent modulation electrodes 404 is 1 nm to 1 mm.

According to some embodiments of the present invention, the distance between the extraction electrode 403 and the modulation electrode 404 in the vertical direction is 1 nm to 1 mm.

According to some embodiments of the present invention, the common electrode pad 401 is connected to the modulation electrode 404 through the lead-out electrode 403 .

According to some embodiments of the present invention, the pixel electrode pad 402 is connected to the modulation electrode 404 through the lead-out electrode 403 .

According to some embodiments of the present invention, the common electrode pad 401 is connected to the negative pole of the external power supply, and the pixel electrode pad 402 is connected to the positive pole of the external power supply; or,

The common electrode pad 401 is connected to the positive pole of the external power supply, and the pixel electrode pad 402 is connected to the negative pole of the external power supply.

According to some embodiments of the present invention, the material of the electrode layer 400 includes one or a combination of the following: metal, alloy and transparent conductive oxide.

According to some embodiments of the present invention, the electrode layer 400 includes Ag, Cu, Au, Al, Pt, Ni, Cr, Ti or ITO.

According to some embodiments of the present invention, the electrode layer 400 is Au. The thickness of Au is 100 nm. The resistivity of the Au material is 2.4×10 ^-8 Ω·m. The width of the modulation electrode 404 is 1 μm.

According to some embodiments of the present invention, as shown in FIG. 4 , the shape of the modulation electrode 404 is a square frame or a square structure, as shown in FIG. The side length of the square of the electrode 404 is 1 mm. The length and width of the common electrode pad 401 are both 100 μm. The length and width of the pixel electrode pads 402 are both 100 μm, and the smaller pitch in the vertical direction is 10 μm. The width of the extraction electrode 403 is 1 μm. The smaller distance between the extraction electrode and the modulation electrode in the vertical direction is 1 μm. The electrode layer has a total of 16 modulation electrodes 404 arranged in a 4*4 array. Correspondingly, each modulation electrode 404 corresponds to a pixel modulation unit 301 below. The number of common electrode pads 401 is one, and the common electrode pad 401 is used to connect the negative electrode of the external power supply, and is connected to one end of each modulation electrode 404 through the lead-out electrode 403 . The number of pixel electrode pads 402 is 16, and the pixel electrode pads 402 are used for connecting the positive electrode of the external power supply. It can be understood that the electrode layer 400 is located above the modulation layer 300, and the common electrode pad 401 and each pixel electrode pad 402 can independently control the voltage on each pixel modulation unit 301, thereby independently controlling the refractive index of the modulation layer 300 , and then realize the two-dimensional distribution of light waves in space.

FIG. 2 schematically shows a schematic structural diagram of a spatial light modulator according to another embodiment of the present invention.

According to some embodiments of the present invention, as shown in FIG. 2 , the spatial light modulator further includes a substrate layer 100 disposed under the reflective layer 200 .

According to some embodiments of the present invention, the substrate layer 100 is a conductor, a semiconductor or an insulator.

According to some embodiments of the present invention, the material of the substrate layer includes Al, Si, SiO ₂ or Al ₂ O ₃ .

According to some embodiments of the present invention, the thickness of the substrate layer 100 is 1 nm to 1 mm.

According to some embodiments of the present invention, the substrate layer 100 is a Si material. The thickness of the substrate layer was 0.4 mm. The substrate layer is mainly used for carrying, which is conducive to achieving high integration. The price of the substrate layer is relatively cheap, which can reduce the production cost.

According to some embodiments of the present invention, the spatial light modulator further includes an insulating layer 500 disposed on the electrode layer 400 .

According to some embodiments of the present invention, the insulating layer 500 is a single crystal material, a polycrystalline material or an amorphous material.

According to some embodiments of the present invention, the insulating layer 500 includes one of the following: SiO ₂ , TiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ or Si ₃ N ₄ .

According to some embodiments of the present invention, the thickness of the insulating layer 500 is 1 nm to 1 mm.

According to some embodiments of the present invention, the insulating layer 500 is Al ₂ O ₃ . The thickness of Al ₂ O ₃ is 200 nm, and the refractive index at a wavelength of 1550 nm is 1.9. It can be understood that the insulating layer has excellent insulating performance and wear resistance, so as to prevent short circuit of the electrodes, prevent the surface of the electrode layer from being oxidized, and protect the surface of the modulation layer.

According to some embodiments of the present invention, the reflection layer 200 , the modulation layer 300 and the electrode layer 400 are all solid, and the reflection layer 200 , the modulation layer 300 and the electrode layer 400 are all inorganic. The use temperature of inorganic solids is usually higher than that of organic substances such as liquid crystals, which has the advantage of high service temperature. At the same time, the anti-aging property of inorganic solids is generally higher than that of organics, and has the advantage of long service life, and the positions and relative positions of the reflective layer 200, the modulation layer 300 and the electrode layer 400 are fixed and immutable. Therefore, the present invention Compared with the liquid crystal spatial light modulator in the prior art, the disclosed spatial light modulator has the characteristics of high stability, high robustness and long service life.

In addition, the modulation layer 300 is a solid, and the modulation layer 300 is an inorganic substance. The minimum uniformity of the thickness of the inorganic solid modulation layer 300 is better than that of the liquid crystal layer, and the minimum thickness of the inorganic solid modulation layer 300 is an order of magnitude smaller than the thickness of the liquid crystal layer, which has the advantage of high modulation speed. The modulation speed of the light modulator is more than 4 orders of magnitude higher than the modulation speed of the liquid crystal spatial light modulator. The modulation speed can reach the order of megahertz.

FIG. 5 schematically shows a flowchart of a method for fabricating a spatial light modulator according to an embodiment of the present invention.

As shown in Figure 5, the present invention also discloses a preparation method of a spatial light modulator, comprising:

S1: preparing the reflective layer 200 on the substrate layer 100;

S2: preparing the modulation layer 300 on the reflective layer 200, and patterning the modulation layer 300 to prepare the pixel modulation unit 301;

S3: preparing the electrode layer 400 on the modulation layer 300, and patterning the electrode layer 400 to prepare the modulation electrode 404, the lead-out electrode 403, the common electrode pad 401 and the pixel electrode pad 402;

S4: preparing the insulating layer 500 on the electrode layer 400, and patterning the insulating layer 500;

The modulation electrode 404 is arranged on the pixel modulation unit 301, the common electrode pad 401 is connected to the negative electrode of the external power supply, and the pixel electrode pad 402 is connected to the positive electrode of the external power supply; or,

The common electrode pad 401 is connected to the positive pole of the external power supply, and the pixel electrode pad 402 is connected to the negative pole of the external power supply.

According to some embodiments of the present invention, the patterning process includes photolithography and etching.

According to some embodiments of the present invention, before patterning the modulation layer 300 , the method further includes thinning and polishing the lower surface of the modulation layer 300 , and bonding the upper surface of the reflective layer 200 and the lower surface of the modulation layer 300 .

According to some embodiments of the present invention, the preparation of the reflective layer 200 , the preparation of the modulation layer 300 , the preparation of the electrode layer 400 and the preparation of the insulating layer 500 include physical methods or chemical methods; the physical methods include one of the following: magnetron sputtering, ion beam sputtering radiation, electron beam evaporation, thermal evaporation or molecular beam epitaxy; chemical methods include one of the following: chemical vapor deposition, electrochemical, sol-gel or hydrothermal methods.

According to some embodiments of the present invention, the preparation method of the spatial light modulator disclosed in the present invention includes 4 times of deposition and 3 times of patterning, a total of 7 small steps, which is far less than that of the liquid crystal spatial light modulator in the prior art. There are 24 processing steps, therefore, the manufacturing method of the spatial light modulator disclosed in the present invention simplifies the processing technology, improves the production efficiency, and reduces the production cost.

In addition, the preparation method of the spatial light modulator disclosed in the present invention only includes processes with relatively low processing difficulty such as deposition and patterning, the number of patterning is small, the alignment deviation is small, and there is no preparation of contact holes and sealing glue. , has the advantage of low processing difficulty, further reduces the production cost and improves the production efficiency.

The yield of the spatial light modulator produced by the preparation method of the spatial light modulator disclosed in the present invention can be as high as 90%. Compared with the yield of the liquid crystal spatial light modulator in the prior art, which is 27%, the yield is improved and the yield is reduced. loss and cost.

The modulation mechanism of the spatial light modulator disclosed in the present invention is as follows: using the change of the optical properties of the modulation layer 300 to modulate the optical parameter of the light wave passing through the spatial light modulator. The spatial light modulator is irradiated with incident light, and some energy (eg, electricity and heat, etc.) is applied to the modulation layer 300 through the electrode layer 400 to change the optical properties (eg, refractive index and absorption coefficient, etc.) of the modulation layer 300 , thereby changing the space The optical parameters (eg: phase and amplitude, etc.) of the reflected light of the light modulator. The reflective layer 200 is located under the modulation layer 300, and the reflective layer 200 has a high reflectivity for a certain wavelength or a certain range of wavelengths, so the reflective layer 200 can reflect the light waves incident through the modulation layer 300 from above and return to the upper side, thereby Realize the modulation of light waves. The electrode layer 400 is located above the modulation layer 300, and the common electrode pad 401 and each pixel electrode pad 402 can independently control the voltage of each pixel modulation unit 301, thereby independently controlling the refractive index of the modulation layer 300, thereby realizing light waves in space. two-dimensional distribution.

Through the above technical solution, the optical properties of the modulation layer are changed by changing the voltage of the pixel modulation unit by using the modulation electrode, thereby realizing the modulation of the light wave. Compared with the liquid crystal spatial light modulator, the layer and the insulating layer have the characteristics of simple structure, high stability, high robustness, long service life and high modulation speed, and the modulation speed can reach the order of megahertz. With the corresponding preparation method, it has many beneficial effects, such as few processing steps, low processing difficulty, high yield and low production cost.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. It should be noted that, in the accompanying drawings or the text of the description, the implementations that are not shown or described are in the form known to those of ordinary skill in the technical field, and are not described in detail. In addition, the above definitions of various components are not limited to various specific structures, shapes or manners mentioned in the embodiments, and those of ordinary skill in the art can simply modify or replace them.

It should also be noted that, in the specific embodiments of the present disclosure, unless known to the contrary, the numerical parameters in the specification and the appended claims are approximations that can Characteristics change. In particular, all numbers used in the specification and claims to indicate compositional dimensions, range conditions, etc., should be understood to be modified by the word "about" in all instances. In general, the meaning expressed is meant to include a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±1% in some embodiments. Example ±0.5% variation.

Those skilled in the art will appreciate that various combinations or/or combinations of features recited in the various embodiments and/or claims of the present invention may be performed, even if such combinations or combinations are not expressly recited in the present invention. In particular, various combinations and/or combinations of the features recited in the various embodiments of the invention and/or the claims may be made without departing from the spirit and teachings of the invention. All such combinations and/or combinations fall within the scope of the present invention.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

1. A spatial light modulator, comprising:

the reflecting layer is used for reflecting incident waves;

a modulation layer disposed on the reflective layer, the modulation layer having adjustable optical properties and comprising a pixel modulation unit;

and the electrode layer is arranged on the modulation layer and comprises a modulation electrode, the modulation electrode is arranged on the pixel modulation unit, and the modulation electrode is used for changing the optical property of the modulation layer by changing the voltage applied to the pixel modulation unit.

2. The spatial light modulator according to claim 1, wherein the number of the modulation electrodes is plural, and the plural modulation electrodes are arranged in an array on the electrode layer.

3. The spatial light modulator of claim 1, wherein the reflective layer comprises at least two layers, each of the layers having a different refractive index; the reflective layer material comprises one of the following materials: a conductor, a semiconductor, or an insulator.

4. The spatial light modulator of claim 3, wherein the reflective layer has an even number of layers, and the odd number of layers is made of SiO₂The thickness is positive integral multiple of 240nm, and the refractive index is 1.5; the material of the layered layer with the number of even layers is Ta2O5, the thickness is positive integral multiple of 190nm, and the refractive index is 2.0.

5. A spatial light modulator according to claim 1 wherein the material of the modulation layer comprises one of: thermo-optic materials, electro-optic materials, acousto-optic materials, or magneto-optic materials.

6. A spatial light modulator according to any of claims 1-5 wherein the electrode layer further comprises:

the common electrode pad is connected with the modulation electrode through an extraction electrode;

the pixel electrode pad is connected with the modulation electrode through an extraction electrode;

the common electrode pad is connected with the negative electrode of an external power supply, and the pixel electrode pad is connected with the positive electrode of the external power supply; or,

the public electrode bonding pad is connected with the positive electrode of an external power supply, and the pixel electrode bonding pad is connected with the negative electrode of the external power supply.

7. The spatial light modulator according to claim 6, wherein the material of the electrode layer comprises one or a combination of the following: metals, alloys, and transparent conductive oxides.

8. A method of fabricating a spatial light modulator, comprising:

preparing a reflective layer on the substrate layer;

preparing a modulation layer on a reflection layer, and carrying out imaging on the modulation layer to prepare a pixel modulation unit;

preparing an electrode layer on the modulation layer, and carrying out imaging on the electrode layer to prepare a modulation electrode, an extraction electrode, a common electrode pad and a pixel electrode pad;

preparing an insulating layer on the electrode layer, and patterning the insulating layer;

the modulation electrode is arranged on the pixel modulation unit, the common electrode pad is connected with the negative electrode of an external power supply, and the pixel electrode pad is connected with the positive electrode of the external power supply; or,

the public electrode bonding pad is connected with the positive electrode of an external power supply, and the pixel electrode bonding pad is connected with the negative electrode of the external power supply.

9. The method of claim 8, further comprising, prior to patterning the modulation layer, thinning and polishing a lower surface of the modulation layer to bond an upper surface of the reflective layer and the lower surface of the modulation layer.

10. The production method according to claim 8, wherein the producing the reflective layer, the producing the modulation layer, the producing the electrode layer, and the producing the insulating layer include a physical method or a chemical method; the physical method comprises one of the following: magnetron sputtering, ion beam sputtering, electron beam evaporation, thermal evaporation or molecular beam epitaxy; the chemical process comprises one of: chemical vapor deposition, electrochemical, sol-gel, or hydrothermal methods.

Images