JP7267213B2 - Observation device and observation method - Google Patents

Description

The present invention relates to an observation device and an observation method.

For example, since it is difficult to observe a transparent observation target such as a cell with a normal microscope, an observation device capable of acquiring a phase image of the observation target such as a quantitative phase microscope is generally used. Several realization methods are known for such observation devices.

One of the conventional techniques (hereinafter referred to as "conventional technique 1") uses a Michelson interferometer or a Mach-Zehnder interferometer that splits and combines two beams, and an object to be observed is placed on the optical path of one of the two beams. to place. Then, in this prior art 1, the optical path length difference (phase difference) between the two light beams is sequentially set to each value by moving a mirror or the like on the optical path, and the interference image of the observed object is acquired. A phase image is created based on the interference image of .

The observation apparatus described in Non-Patent Document 1 (hereinafter referred to as "prior art 2") is an application of a phase-contrast microscope, in which object light (diffracted light) and reference light (non-diffracted light) are coaxially arranged. Propagate. In this prior art 2, by adjusting the phase of the reference light with respect to the object light by using a spatial light modulator, the phase difference between the object light and the reference light is sequentially set to each value to obtain an interference image of the observation target. is obtained, and a phase image is created based on these multiple interference images.

The observation apparatus described in Non-Patent Document 2 (hereinafter referred to as "prior art 3") uses a Michelson interferometer that splits and combines two light beams by a polarization beam splitter, and one of the two light beams An observation object is placed on the optical path. In this prior art 3, the object light and the reference light, which are combined and output by the Michelson interferometer, are converted into circularly polarized light by a quarter-wave plate, respectively, and then captured by a polarizing camera. Interference images of the observed object are simultaneously obtained with the phase difference between the light and the object set to each value, and a phase image is created based on the plurality of interference images.

In addition, these observation devices can acquire not only phase images of observation objects but also amplitude images, and can acquire complex amplitude images.

Zhuo Wang, et al, “Spatial lightinterference microscopy (SLIM),” OPTICS EXPRESS, Vol.19, No.2, pp.1016-1026 (2011). Katherine Creath, et al, “Dynamicquantitative phase imaging for biological objects using a pixelated phase mask,”BIOMEDICAL OPTICS EXPRESS, Vol.3, No.11, pp.2866-2880 (2012).

Compared with the prior art 2 in which the object light and the reference light are coaxially propagated, the prior arts 1 and 3 use a Michelson interferometer or a Mach-Zehnder interferometer to split and combine the two beams. Not easy to adjust and poor vibration resistance.

Compared with Conventional Technique 3, in which interference images of an observation target are simultaneously obtained by setting the phase difference between the object light and the reference light to each value, Conventional Techniques 1 and 2 have Since the phase difference is sequentially set to each value and the interference image of the observed object is acquired, it takes time to acquire the plurality of interference images.

Further, in the prior art 2, since an interference image is obtained by interfering object light (diffracted light) and reference light (non-diffracted light) with a configuration applying a phase-contrast microscope, the obtained phase image has a halo ( Halo) occurs and quantification is poor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides an observation apparatus and an observation method that can easily adjust the optical system and obtain complex amplitude images with improved quantification in a short time. for the purpose.

The observation device of the first aspect of the present invention has (1) a light source that outputs spatially incoherent light and (2) a passage area that allows the light to pass therethrough. (3) a first optical system that receives the light output from the aperture and forms a Fourier transform image of the light output from the aperture; (4) By inputting light from the first optical system to an observation object placed at a position where a Fourier transform image is formed by the first optical system, inputting the light output from the observation object, A second optical system that forms a Fourier transform image of the output light; (6) a polarizer that outputs light; and (6) a first region that is disposed at a position where a Fourier transform image is formed by a second optical system and that corresponds to the passage region of the aperture, and a second region other than the first region. selectively outputting linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light, out of the light input from the second optical system to the first region, a patterned polarizer for selectively outputting linearly polarized light having a plane of polarization of 35° to 55° relative to the plane of polarization of the input light, out of the light input from the second optical system to the second region; , (7) a third optical system for inputting the light output from the patterned polarizer and forming a Fourier transform image of the output light from the patterned polarizer; and (8) arranged on the optical path of the third optical system, At a position where a Fourier transform image is formed by a quarter-wave plate that circularly polarizes the light output from the first region and the second region of the patterned polarizer in different rotational directions, and (9) the third optical system. Two light beams circularly polarized in different rotational directions by a quarter wave plate are input, and an interference image on the imaging plane is obtained for each component of three or more polarization planes. and (10) an analysis unit that creates a complex amplitude image of the observed object based on the interference images for each of the components of the three or more polarization planes acquired by the polarization camera.

The observation device according to the second aspect of the present invention has (1) a light source that outputs spatially incoherent linearly polarized light, and (2) a passage area that allows the light to pass therethrough, and is used to transmit the light output from the light source. (3) a first optical system that receives the light output from the aperture and forms a Fourier transform image of the light output from the aperture; (4) inputting light from the first optical system into an observation object placed at a position where a Fourier transform image is formed by the first optical system; a second optical system for forming a Fourier transform image of output light from an object; A straight line having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light in the light input from the second optical system to the first region. Linearly polarized light that selectively outputs polarized light and has a plane of polarization of 35° to 55° relative to the plane of polarization of the input light among the light that has entered the second region from the second optical system. (6) a third optical system that receives the light output from the patterned polarizer and forms a Fourier transform image of the output light from the patterned polarizer; (7) a third (8) a third optical system; has an imaging plane arranged at a position where a Fourier transform image is formed by, inputs two lights that are circularly polarized in different rotational directions by a quarter-wave plate, and has three or more polarization plane components, respectively and (9) an analysis unit that creates a complex amplitude image of the observed object based on the interference images for each of the three or more polarization plane components acquired by the polarization camera. And prepare.

In one aspect of the observation apparatus according to the first aspect or the second aspect of the present invention, it is preferable that the first optical system and the second optical system have a common portion for inputting and outputting light with respect to the observed object. Preferably, the second optical system includes a relay optical system. A polarization camera preferably has a structure in which a plurality of pixels are arranged two-dimensionally on an imaging surface, and acquires a two-dimensional interference image. The polarization camera has a structure in which a plurality of pixels are arranged one-dimensionally on the imaging plane, and it is also suitable for obtaining a one-dimensional interference image. It is preferable to obtain a two-dimensional interference image of the observed object by relatively moving the observed object in a different direction.

Further, in one aspect of the observation apparatus of the first aspect or the second aspect of the present invention, the optical element constituting the second optical system or the observation object is scanned in a direction parallel to the optical axis of the second optical system, and the polarized light is Preferably, the camera acquires an interference image at each scanning position, and the analysis unit creates a three-dimensional complex amplitude image of the observed object based on the interference images acquired by the polarization camera at each scanning position. .

The optical module of the present invention has: (1) a first region and a second region other than the first region, and out of light input from the second optical system to the first region, the polarization plane of the input light is Selectively output linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light among the light input from the second optical system to the second region a patterned polarizer for selectively outputting linearly polarized light having a plane of polarization of 35° to 55° at 2; and (3) an imaging plane for inputting two lights circularly polarized in different rotational directions by the quarter-wave plate, and three or more polarization plane components and a polarization camera for acquiring an interference image on the imaging plane for each. In one aspect, the optical module of the present invention preferably further includes a polarizer that is arranged upstream of the patterned polarizer and that outputs input light to the patterned polarizer as linearly polarized light.

The observation method according to the first aspect of the present invention includes (1) outputting spatially incoherent light from a light source, and (2) using an aperture having a passage area for allowing the light to pass therethrough, and observing the light output from the light source. (3) form a Fourier transform image of the light output from the aperture by the first optical system that receives the light output from the aperture; (4) ) By the second optical system that inputs the light output from the observation object by inputting the light from the first optical system into the observation object placed at the position where the Fourier transform image is formed by the first optical system , forms a Fourier transform image of the output light from the observation object, and (5) a polarizer arranged on the optical path from the light source to the position where the Fourier transform image is formed by the second optical system. (6) a first region corresponding to the passage region of the aperture, which is arranged at a position where a Fourier transform image is formed by the second optical system, and a second region other than the first region; By the patterned polarizer having, linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light, among the light input from the second optical system to the first region, is selectively selected. and selectively outputs linearly polarized light having a plane of polarization of 35° to 55° relative to the plane of polarization of the input light, among the light input from the second optical system to the second region. , (7) forming a Fourier transform image of the output light from the patterned polarizer by a third optical system for inputting the light output from the patterned polarizer, and (8) arranged on the optical path of the third optical system The light output from the first region and the second region of the patterned polarizer is circularly polarized in different directions by the quarter-wave plate, and (9) the third optical system forms a Fourier transform image. A polarization camera having an arranged imaging plane inputs two lights that have been circularly polarized in different rotational directions by a quarter-wave plate, and an interference image on the imaging plane is obtained for each component of three or more polarization planes. (10) creating a complex amplitude image of the observed object based on the interference images for each of the three or more polarization plane components acquired by the polarization camera;

The observation method of the second aspect of the present invention comprises: (1) outputting spatially incoherent linearly polarized light from a light source; (3) forming a Fourier transform image of the light output from the aperture by means of a first optical system for inputting the light output from the aperture; and (4) a second optical system for inputting the light output from the observation object by inputting the light from the first optical system to the observation object arranged at the position where the Fourier transform image is formed by the first optical system. The optical system forms a Fourier transform image of the output light from the observation object, and (5) a first area and a first area which are arranged at positions where the Fourier transform image is formed by the second optical system and which correspond to the passage area of the aperture. With a patterned polarizer having a second region other than one region, the light input from the second optical system to the first region has a polarization plane of −10° to +10° relative to the polarization plane of the input light. and selectively outputs linearly polarized light having selectively outputting polarized light; (6) forming a Fourier transform image of the output light from the patterned polarizer by a third optical system for inputting the light output from the patterned polarizer; The quarter-wave plate arranged on the optical path of the optical system converts the light output from the first region and the second region of the patterned polarizer into circularly polarized lights with different rotation directions, and (8) the third optical system A polarization camera having an imaging plane arranged at a position where a Fourier transform image is formed inputs two lights that are circularly polarized in different rotational directions by a quarter-wave plate, and three or more polarization plane components are detected. An interference image on the imaging plane is acquired for each of them, and (9) a complex amplitude image of the observed object is created based on the interference images for each of the components of the three or more polarization planes acquired by the polarization camera.

In one aspect of the observation method of the first aspect or the second aspect of the present invention, it is preferable that the first optical system and the second optical system have a common portion for inputting and outputting light to the observed object. Preferably, the second optical system includes a relay optical system. A polarization camera preferably has a structure in which a plurality of pixels are arranged two-dimensionally on an imaging surface, and acquires a two-dimensional interference image. The polarization camera has a structure in which a plurality of pixels are arranged one-dimensionally on the imaging plane, and it is also suitable for obtaining a one-dimensional interference image. It is preferable to obtain a two-dimensional interference image of the observed object by relatively moving the observed object in a different direction.

Further, in one aspect of the observation method of the first aspect or the second aspect of the present invention, the optical element constituting the second optical system or the observation object is scanned in a direction parallel to the optical axis of the second optical system, and the polarized light is Preferably, the camera acquires an interference image at each position of the scan, and a three-dimensional complex amplitude image of the observed object is generated based on the interference images acquired by the polarization camera at each position of the scan.

According to the present invention, the adjustment of the optical system is easy, and a complex amplitude image with improved quantification can be obtained in a short period of time.

FIG. 1 is a diagram showing the configuration of an observation device 1 according to the first embodiment. FIG. 2 is a diagram illustrating the polarizer 12, the aperture 13, and the patterned polarizer 14. FIG. 2(a) shows the polarizer 12, FIG. 2(b) shows the aperture 13, and FIG. 2(c) shows the patterned polarizer 14. FIG. FIG. 3 is a diagram showing a configuration example of the image sensor of the polarization camera 16. As shown in FIG. FIG. 4 is a diagram showing another configuration example of the image sensor of the polarization camera 16. As shown in FIG. FIG. 5 is a diagram for explaining the light output from the patterned polarizer 14. FIG. FIG. 6 shows the original image used in the simulation. FIG. 7(a) is a phase image created according to the present embodiment when the passage area 13a of the aperture 13 is narrow. FIG. 7B is an image showing the difference between this phase image and the original image. FIG. 8(a) is a phase image created by prior art 2 when the passage area 13a of the aperture 13 is narrow. FIG. 8(b) is an image showing the difference between this phase image and the original image. FIG. 9(a) is a phase image created according to the present embodiment when the passage area 13a of the aperture 13 is wide. FIG. 9B is an image representing the difference between this phase image and the original image. FIG. 10(a) is a phase image created by prior art 2 when the passage area 13a of the aperture 13 is wide. FIG. 10(b) is an image showing the difference between this phase image and the original image. FIG. 11 is a diagram showing the configuration of an observation device 1A that is a modification of the observation device 1 of the first embodiment. FIG. 12 is a diagram showing the configuration of the observation device 2 of the second embodiment. FIG. 13 is a diagram showing the configuration of the observation device 3 of the third embodiment. FIG. 14 is a diagram showing the configuration of an observation device 3A that is a modification of the observation device 3 of the third embodiment. FIG. 15 is a diagram showing the configuration of an observation device 4 according to the fourth embodiment. FIG. 16 is a diagram showing the configuration of an observation device 5 according to the fifth embodiment. FIG. 17 is a diagram showing the configuration of an observation device 5A that is a modification of the observation device 5 of the fifth embodiment. FIG. 18 is a diagram showing the configuration of the observation device 6 of the sixth embodiment. FIG. 19 is a diagram showing the configuration of the observation device 7 of the seventh embodiment. FIG. 20 is a diagram showing the configuration of an observation device 1B that is a modification of the observation device 1 of the first embodiment. FIG. 21 is a diagram showing the configuration of an observation device 1C that is a modification of the observation device 1 of the first embodiment. FIG. 22 is a diagram showing the configuration of an observation device 7B that is a modification of the observation device 7 of the seventh embodiment. FIG. 23 is a diagram showing the configuration of an observation device 7C that is a modification of the observation device 7 of the seventh embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted. The present invention is not limited to these exemplifications, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of equivalents of the scope of the claims.

FIG. 1 is a diagram showing the configuration of an observation device 1 according to the first embodiment. The observation device 1 includes a light source 11, a polarizer 12, an aperture 13, a patterned polarizer 14, a quarter-wave plate 15, a polarization camera 16, an analysis section 18, a first optical system 20, a second optical system 30 and a third optical system. A system 40 is provided.

The light source 11 outputs spatially incoherent light. The light output from the light source 11 may be temporally coherent or temporally incoherent. The light output from the light source 11 may be linearly polarized or non-polarized. The light source 11 preferably includes, for example, a halogen lamp, a light-emitting diode or a laser diode, and further includes a diffuser plate behind it.

Polarizer 12 is optically connected to light source 11 . The polarizer 12 receives the light output from the light source 11 and outputs linearly polarized light having a plane of polarization corresponding to the orientation of the optical axis of the polarizer 12 .

Aperture 13 is optically connected to polarizer 12 . Aperture 13 has a passage area for passing light, selectively passes light that has reached the passage area among the light output from polarizer 12, and outputs light that has reached an area other than the passage area. block the

The first optical system 20 is provided between the aperture 13 and the observed object S, and includes one or more lenses. The first optical system 20 receives the light output from the aperture 13 and forms a Fourier transform image of the light output from the aperture 13 .

The observation target S is arranged at a position where a Fourier transform image is formed by the first optical system 20 .

The second optical system 30 is provided between the observed object S and the patterned polarizer 14 and includes one or more lenses. The second optical system 30 receives the light output from the observation object S when the light is input from the first optical system 20 to the observation object S, and outputs a Fourier transform image of the output light from the observation object S. to form

The patterned polarizer 14 is arranged at a position where the Fourier transform image is formed by the second optical system 30 . That is, the patterned polarizer 14 is arranged at a position having an optically conjugate relationship with respect to the aperture 13 via the first optical system 20 and the second optical system 30 . The patterned polarizer 14 has a first area corresponding to the passage area of the aperture 13 and a second area other than the first area. The patterned polarizer 14 is relatively −10° to +10° (preferably −5° to +5°, It selectively outputs linearly polarized light having a plane of polarization of 0°, most preferably. Further, the patterned polarizer 14 is relatively 35° to 55° (preferably 40° to 50°, It selectively outputs linearly polarized light having a plane of polarization of 45°, most preferably.

The third optical system 40 is provided between the patterned polarizer 14 and the imaging plane of the polarization camera 16 and includes one or more lenses. The third optical system 40 receives the light output from the patterned polarizer 14 and forms a Fourier transform image of the output light from the patterned polarizer 14 .

The quarter-wave plate 15 is arranged on the optical path of the third optical system 40 between the patterned polarizer 14 and the imaging plane of the polarization camera 16 . The quarter-wave plate 15 converts the linearly polarized light output from the first region and the second region of the patterned polarizer 14 into circularly polarized light with different rotation directions and outputs the circularly polarized light.

The polarizing camera 16 has an imaging plane arranged at a position where a Fourier transform image is formed by the third optical system 40 . The polarization camera 16 receives two lights circularly polarized in different directions of rotation by the quarter-wave plate 15, and acquires interference images on the imaging plane for each component of three or more polarization planes. In addition, the circularly polarized light in the present invention is not limited to the case where the phase difference is ±π/2 [rad] and the amplitude is equal between the electric field vectors in two mutually orthogonal directions, and includes elliptically polarized light.

The analysis unit 18 creates a complex amplitude image (amplitude image and phase image) of the observed object S based on the interference images for each of the three or more polarization plane components acquired by the polarization camera 16 . The analysis unit 18 is, for example, a computer. The analysis unit 18 includes a calculation unit including a CPU for performing calculation processing such as creation of a complex amplitude image, a storage unit including a hard disk drive for storing the interference image and the complex amplitude image, a RAM and a ROM, and the like, and an interference image and the complex amplitude image. A display unit including a liquid crystal display for displaying an amplitude image and the like, and an input unit including a keyboard, a mouse, etc. for receiving input of various conditions for obtaining an interference image and displaying the image are provided.

FIG. 2 is a diagram illustrating the polarizer 12, the aperture 13, and the patterned polarizer 14. FIG. 2(a) shows the polarizer 12, FIG. 2(b) shows the aperture 13, and FIG. 2(c) shows the patterned polarizer 14. FIG. These figures are views in the direction of the chief ray.

The polarizer 12 (FIG. 2A) receives the light output from the light source 11 and outputs linearly polarized light having a plane of polarization corresponding to the orientation of the optical axis of the polarizer 12 . The hatched orientation in FIG. 2A indicates the orientation of the optical axis of the polarizer 12 .

The aperture 13 (FIG. 2(b)) has a passage area 13a through which light passes and a blocking area 13b other than the passage area 13a. The aperture 13 selectively transmits and outputs the light that has reached the passing region 13a among the light that is output from the polarizer 12, and blocks the light that has reached the blocking region 13b. The passage area 13a may be an opening or a transparent member. The passing area 13a may be ring-shaped as shown in this figure, or may be of any shape. The passing area 13a may be a single area as shown in this figure, or may consist of a plurality of partial areas.

The patterned polarizer 14 (FIG. 2(c)) is arranged at a position having an optically conjugate relationship with respect to the aperture 13 via the first optical system 20 and the second optical system 30 . The patterned polarizer 14 has a first region 14a corresponding to the passing region 13a of the aperture 13 and a second region 14b other than the first region 14a. The patterned polarizer 14 is relatively -10° to +10° (preferably -5° to +5° , most preferably 0°). The patterned polarizer 14 is relatively 35° to 55° (preferably 40° to 50°, most preferably 40° to 50°, most Preferably, it selectively outputs linearly polarized light having a plane of polarization of 45°.

The first region 14a of the patterned polarizer 14 may be a polarizer, an aperture, or a transparent member. The second region 14b of the patterned polarizer 14 is a polarizer. The hatched orientations of the first region 14a and the second region 14b in FIG. 2(c) indicate the orientation of the optical axis of each polarizer.

FIG. 3 is a diagram showing a configuration example of the image sensor of the polarization camera 16. As shown in FIG. The image sensor 16A shown in this figure includes a photodiode array 161 formed on a semiconductor substrate, a polarizer array 162 provided on the photodiode array, and a lens array 163 provided on the polarizer array. and has a structure in which these are laminated. A plurality of photodiodes are arranged two-dimensionally in the photodiode array 161 . For each photodiode of the photodiode array 161, one polarizer of the polarizer array 162 is provided correspondingly, and one lens of the lens array 163 is provided correspondingly.

Each polarizer in polarizer array 162 has an optic axis in one of four orientations (0°, 45°, 90°, 135°). In this figure, the hatched orientation of each polarizer of the polarizer array 162 indicates the orientation of the optic axis of the polarizer. By using this image sensor 16A, two-dimensional images of linearly polarized light in four directions can be taken simultaneously. An image sensor (Polarsens (registered trademark)) commercialized by Sony Corporation has the configuration shown in this figure. An image sensor (Area Scan Polarization Sensor) commercialized by Teledyne DALSA also has the configuration shown in this figure.

FIG. 4 is a diagram showing another configuration example of the image sensor of the polarization camera 16. As shown in FIG. The image sensor 16B shown in this figure comprises photodiode arrays 164a-164d formed on a semiconductor substrate, and polarizers 165a-165c provided on the photodiode arrays 164a-164c. No polarizer is provided on the photodiode array 164c. In each of the photodiode arrays 164a-164d, a plurality of photodiodes are arranged one-dimensionally in the x-direction. The photodiode arrays 164a-164d are arranged in parallel in the y direction.

The optic axis orientation of the polarizer 165a on the photodiode array 164a is 0°, the optic axis orientation of the polarizer 165b on the photodiode array 164b is 135, and the optical axis orientation of the polarizer 165c on the photodiode array 164c is 0°. The orientation of the axis is 90°. In this figure, the hatched orientation of each polarizer indicates the orientation of the optic axis of the polarizer. By using this image sensor 16B, one-dimensional images of linearly polarized light in three directions can be taken simultaneously. Also, by relatively moving the observation object S in a direction different from the x-direction (for example, the y-direction), two-dimensional images of linearly polarized light in three azimuths can be acquired simultaneously. For example, as in flow cytometry, the observation object S can be a cell that moves with a fluid in a transparent tube. An image sensor (Line Scan Polarization Sensor) commercialized by Teledyne DALSA has the configuration shown in this figure.

Next, a method of acquiring a complex amplitude image of the observed object S using the observation device 1 will be described.

A light source 11 outputs spatially incoherent light. The polarizer 12 to which the light output from the light source 11 is input outputs linearly polarized light having a plane of polarization corresponding to the orientation of the optical axis of the polarizer 12 . Using an aperture 13 having a light-passing region 13a, light that has reached the light-passing region 13a out of the light output from the polarizer 12 is selectively passed through and output. A first optical system 20 that receives the light output from the aperture 13 forms a Fourier transform image of the light output from the aperture 13 . An observation target S is arranged at a position where a Fourier transform image is formed by the first optical system 20 . A Fourier transform image of the output light from the observation target S is obtained by the second optical system 30 that inputs the light output from the observation target S by inputting the light from the observation target S from the first optical system 20 to the observation target S. Form.

A patterned polarizer 14 is arranged at a position where a Fourier transform image is formed by the second optical system 30 . The patterned polarizer 14 has a first region 14a corresponding to the passing region 13a of the aperture 13 and a second region 14b other than the first region 14a. With this patterned polarizer 14, the light input from the second optical system 30 to the first region 14a is relatively -10° to +10° (preferably -5° to +5°) with respect to the plane of polarization of the input light. degree, most preferably 0 degree). In addition, the patterned polarizer 14 allows the light input from the second optical system 30 to the second region 14b to be polarized at a angle of 35° to 55° (preferably 40° to 50°) relative to the plane of polarization of the input light. 450°, most preferably 450°).

A Fourier transform image of the output light from the patterned polarizer 14 is formed by the third optical system 40 that receives the light output from the patterned polarizer 14 . The quarter-wave plate 15 arranged on the optical path of the third optical system 40 converts the light output from the first region 14a and the second region 14b of the patterned polarizer 14 into circularly polarized lights with different rotational directions. A polarization camera 16 having an imaging surface arranged at a position where a Fourier transform image is formed by the third optical system 40 inputs two lights circularly polarized in different rotational directions by the quarter-wave plate 15 . , an interference image on the imaging plane (that is, three or more interference images with different phase differences) for each of three or more polarization plane components.

Then, the analysis unit 18 creates a complex amplitude image of the observed object S based on the three or more interference images acquired by the polarization camera 16 . Three or more interference images with different phase differences are required to create a complex amplitude image. For example, when four interference images I ₁ to I ₄ with different phase differences of 90° are obtained, the phase image φ is obtained by the formula φ=arg{(I ₁ −I ₃ )+i(I ₂ −I ₄ )}. can be created and the amplitude image R can be created by the formula R={(I ₁ −I ₃ ) ² +(I ₂ −I ₄ ) ² } ^1/2 , and a complex amplitude image can also be created can do. It should be noted that I ₁ to I ₄ , φ and R are functions of pixel position, and the equations are calculated pixel by pixel. arg is an operator that obtains the argument of a complex number. i is the imaginary unit.

Next, the halo reduction effect will be described. In the following description, it is assumed that the orientations of the planes of polarization of the linearly polarized light output from the first region 14a and the second region 14b of the patterned polarizer 14 are different from each other by 45°.

FIG. 5 is a diagram for explaining the light output from the patterned polarizer 14. FIG. In this figure, the hatched azimuth indicates the azimuth of the plane of polarization of the output light from the patterned polarizer 14 . Since the output light Ea from the first region 14a of the patterned polarizer 14 has a plane of polarization different from the plane of polarization of the output light Eb from the second region 14b of the patterned polarizer 14 by approximately 45°, the output light Eb can be decomposed into light Ea1 having a plane of polarization oriented parallel to the plane of polarization of , and light Ea2 having a plane of polarization oriented perpendicular thereto. A combination of light Eb and light Ea1 having planes of polarization in the same direction can be used as object light, and light Ea2 having a plane of polarization in a direction perpendicular to this can be used as reference light.

Since the patterned polarizer 14 is arranged at the position where the Fourier transform image of the output light from the observation object S is formed by the second optical system 30, the object light (light Eb and The light Ea1) has components of almost the entire spatial frequency of the observation object S. FIG. In addition, since the reference light Ea2 output from the patterned polarizer 14 is predominantly non-diffracted light, a limited band including the spatial frequency 0 of the observation object S (a band corresponding to the width of the first region 14a ).

Since the imaging plane of the polarization camera 16 is arranged at a position where the Fourier transform image of the output light from the patterned polarizer 14 is formed by the third optical system 40, the imaging plane of the polarization camera 16 receives pattern polarized light. The object light (light Eb and light Ea1) output from the element 14 reproduces the image of the observed object S relatively faithfully. Further, the imaging plane of the polarization camera 16 is irradiated with the reference light (non-diffracted light) Ea2 output from the patterned polarizer 14 .

In this embodiment, the halo is reduced because the image of the observed object S is relatively faithfully reproduced on the imaging surface of the polarization camera 16 . In addition, the narrower the pass region 13a of the aperture 13 (that is, the narrower the first region 14a of the patterned polarizer 14), the greater the ratio of the non-diffracted light included in the reference light, thereby further reducing the halo. be. In the present embodiment, the object light is a combination of the light Eb and the light Ea1, whereas in the conventional technique 2, the object light corresponds only to the light Eb. occurs in

Next, it will be described in detail how the observation device 1 or the observation method according to the present embodiment can acquire a complex amplitude image of the observed object S. FIG. In the following, for ease of explanation, it is assumed that the light source 11 outputs spatially coherent light and the patterned polarizer is divided into a central region and a peripheral region.

Among the polarization states of light, the vector representing horizontal polarization is _eH , the vector representing horizontal polarization is _eV , the vector representing 45° polarization is _eD , and the vector representing 135° polarization is _eA . Let e _R be a vector representing circularly polarized light, and let e _L be a vector representing left-handed circularly polarized light. These vectors have the following relationships (1) to (4).

When circularly polarized light is input to the polarizer, the phase of the light output from the polarizer is the vector of the polarization state of the output light (any of e _H , e _V , e _D , and e _A ). It is represented by the inner product with the polarization state vector (either e _R or e _L ) of the input light. The following equations (5) to (12) hold for the inner product between two vectors. By using these relationships, an interference image corresponding to each phase shift amount can be acquired.

Since _eH.eR and _eH.eL have the same phase, when two circularly polarized lights _with different rotation directions are projected to horizontally polarized light by a polarizer, two light beams are output from the polarizer _. The light will be in phase. Since _eV・_eR and _eV・_eL have opposite phases, when two circularly polarized lights with different rotation directions are projected by a polarizer into vertically polarized light, the two light beams output from the polarizer are The phase difference between the lights will be 180°.

Since _eD・_eR and _eD・_eL differ in phase by 90°, when two circularly polarized lights with different rotation directions are projected by a polarizer into 45° polarized light, the output from the polarizer is The phase difference between the two beams of light will be 90°. Since e _A · e _R and e _A · e _L have a phase difference of 270°, when two circularly polarized lights with different rotation directions are projected by a polarizer into 135° polarized light, the output from the polarizer is The phase difference between the two light beams will be 270°.

Let U(x) be the wavefront of light to be measured. x is a variable representing the position. The Fourier transform of U(x) is represented as u(k) (equation (13) below). k is a variable representing spatial frequency.

Considering the case where the planes of polarization of linearly polarized light selectively transmitted by the central region and the peripheral region of the patterned polarizer are orthogonal to each other, the following is the case. The output light U(x) from the observed object is Fourier-transformed by the optical system, and its Fourier-transformed image u(k) is formed at the position of the patterned polarizer. The light of u(k) that has passed through the central region of the patterned polarizer forms an image U _c (x) represented by the following equation (14) on the imaging surface of the polarizing camera. p _c (k) in this equation is the mask in the spatial frequency domain corresponding to the central region of the patterned polarizer and corresponds to the low frequency components of U(x).

The image U ₋ (x) formed on the imaging plane of the polarization camera by the light passing through the peripheral region of the patterned polarizer is expressed as U(x) minus U _c (x) ((15 )formula). Therefore, an interference image obtained by imaging with a polarization camera is represented by the following formula (16). The subscript X in this formula indicates the polarization state (any of H, V, D, and A) captured by the polarization camera.

Since the inner product between the vectors representing the polarization states has the above-described phase relationship, the interference images _IH (x), _IV (x), _ID (x), I _A (x) corresponds to the measurement result at each phase shift amount in the phase shift method. Therefore, using these interference images, a complex amplitude image C(x) can be acquired by the following equation (17).

Assume an ideal case where the size of the central region of the patterned polarizer is infinitesimal. In this case, p _c (k) is represented by a delta function (equation (18) below). At this time, the above equation (14) becomes the following equation (19). U ₀ is a constant and corresponds to the mean value of U(x). At this time, the complex amplitude image C(x) of the above equation (17) is represented by the following equation (20).

Since U ₀ is a constant, the complex amplitude of U ₋ (x) will be measured, which does not match U(x). In other words, even in such an ideal case, the quantification of the measured values is lost. This loss of quantification causes the low frequency content of the image to be lost. The phenomenon known as halo in phase-contrast microscopy is based on this same mechanism.

On the other hand, in the present embodiment, the patterned polarizer 14 projects the diffracted light into polarized light inclined at 45° with respect to the non-diffracted light. The wavefront U'(x) of the light incident on the polarization camera 16 at this time is represented by the following equation (21). A complex amplitude image C(x) obtained as a result is represented by the following equation (22). While the low-frequency component of the image is lost in prior art 2, the low-frequency component of the image is not lost in this embodiment. Therefore, in the present embodiment, image loss is suppressed, and occurrence of a halo-like phenomenon is suppressed.

Next, the result of confirming the halo reduction effect by simulation will be described. FIG. 6 shows the original image used in the simulation. Using this original image as an observation object S, phase images were created by the present embodiment and prior art 2, respectively, when the passage area 13a of the aperture 13 was narrow and wide.

FIG. 7(a) is a phase image created according to the present embodiment when the passage area 13a of the aperture 13 is narrow. FIG. 7B is an image showing the difference between this phase image and the original image.

FIG. 8(a) is a phase image created by prior art 2 when the passage area 13a of the aperture 13 is narrow. FIG. 8(b) is an image showing the difference between this phase image and the original image.

FIG. 9(a) is a phase image created according to the present embodiment when the passage area 13a of the aperture 13 is wide. FIG. 9B is an image representing the difference between this phase image and the original image.

FIG. 10(a) is a phase image created by prior art 2 when the passage area 13a of the aperture 13 is wide. FIG. 10(b) is an image showing the difference between this phase image and the original image.

As can be seen from these figures, halos are reduced in the phase images created by this embodiment compared to the phase images created by the prior art 2. FIG. Further, when the passage area 13a of the aperture 13 is narrow, the halo reduction effect of the present embodiment is remarkable.

As described above, in this embodiment, since the object light and the reference light propagate coaxially, the optical system can be easily adjusted, and a mechanism for stabilizing the optical path length is unnecessary, resulting in excellent vibration resistance. Interference images of the observed object can be acquired simultaneously (single-shot) with the phase difference between the object beam and the reference beam set to each value, so the time required to acquire these multiple interference images is short. In addition, compared with the prior art 2, the halo is reduced in the present embodiment and the quantification is excellent.

Next, configurations of other embodiments and modifications will be described. Elements that are the same as in the configuration of the observation device 1 shown in FIG. 1 are denoted by the same reference numerals, and overlapping descriptions are omitted. These have the same effects as the observation device 1 of the first embodiment shown in FIG.

FIG. 11 is a diagram showing the configuration of an observation device 1A that is a modification of the observation device 1 of the first embodiment. Compared with the configuration of the viewing device 1 shown in FIG. 1, the viewing device 1A shown in FIG. 11 differs in the position where the polarizer 12 is provided. In this configuration example, the polarizer 12 is provided immediately before the patterned polarizer 14 . The polarizer 12 may be provided at any position on the optical path from the light source 11 to the patterned polarizer 14 (the position where the Fourier transform image is formed by the second optical system 30). When the polarizer 12 is provided on the optical path between the observation object S and the patterned polarizer 14, even if the observation object S has birefringence, the interference image and the complex amplitude image are preferable. can be obtained.

FIG. 12 is a diagram showing the configuration of the observation device 2 of the second embodiment. Compared to the configuration of the observation device 1 shown in FIG. 1, the observation device 2 shown in FIG. The difference is that the unnecessary polarizer 12 is not provided. In this case, the orientation of the plane of polarization of the linearly polarized light output from the first region 14 a and the second region 14 b of the patterned polarizer 14 is set according to the orientation of the plane of polarization of the linearly polarized light output from the light source 11 .

FIG. 13 is a diagram showing the configuration of the observation device 3 of the third embodiment. Compared with the configuration of the observation device 1 shown in FIG. 1, the observation device 3 shown in FIG. In this embodiment, the second optical system 30 includes lenses 32 and 33 as a relay optical system in addition to the objective lens 31 . Also, the patterned polarizer 14, the quarter wave plate 15, the polarization camera 16, the lens 33 and the third optical system 40 can be placed in a common housing to form an optical module 51. FIG. By attaching this optical module 51 to a commercially available phase-contrast microscope, the observation device 3 can be constructed.

FIG. 14 is a diagram showing the configuration of an observation device 3A that is a modification of the observation device 3 of the third embodiment. Compared with the configuration of the observation device 3 shown in FIG. 13, the observation device 3A shown in FIG. 14 differs in the position where the polarizer 12 is provided. In this configuration example, the polarizer 12 is provided immediately before the patterned polarizer 14 . When the polarizer 12 is provided on the optical path between the observation object S and the patterned polarizer 14, even if the observation object S has birefringence, the interference image and the complex amplitude image are preferable. can be obtained. Also, the polarizer 12, the patterned polarizer 14, the quarter-wave plate 15, the polarization camera 16, the lens 33 and the third optical system 40 can be placed in a common housing to form an optical module 52. FIG. By attaching this optical module 52 to a commercially available phase-contrast microscope, the observation device 3A can be constructed.

FIG. 15 is a diagram showing the configuration of an observation device 4 according to the fourth embodiment. Compared to the configuration of the observation device 3 shown in FIG. 13, the observation device 4 shown in FIG. The difference is that the unnecessary polarizer 12 is not provided. In this case, the orientation of the plane of polarization of the linearly polarized light output from the first region 14 a and the second region 14 b of the patterned polarizer 14 is set according to the orientation of the plane of polarization of the linearly polarized light output from the light source 11 .

Although the viewing device described so far has a transmissive configuration, the viewing device may have a reflective configuration as described below. In the case of a reflective configuration, the first optical system and the second optical system can share a portion for inputting/outputting light to/from the observed object S. FIG.

FIG. 16 is a diagram showing the configuration of an observation device 5 according to the fifth embodiment. The observation device 5 includes lenses 21 , 22 and 23 and a beam splitter 17 as a first optical system provided between the aperture 13 and the observation object S. The observation device 5 also includes lenses 23 , 32 , 33 and a beam splitter 17 as a second optical system provided between the observation object S and the patterned polarizer 14 . A polarizer 12 is provided between the light source 11 and the aperture 13 . Light output from the light source 11 reaches the beam splitter 17 via the polarizer 12 , the aperture 13 , the lenses 21 and 22 , and is reflected by the beam splitter 17 to the lens 23 . The light passes through the lens 23 and irradiates the observation object S, and is reflected by the bottom surface of the container containing the observation object S. FIG. The reflected light is input to patterned polarizer 14 via lens 23 , beam splitter 17 , lens 32 and lens 33 . Also in this configuration, the patterned polarizer 14, the quarter-wave plate 15, the polarization camera 16, the lens 33 and the third optical system 40 can be housed in a common housing to form the optical module 51. FIG. By attaching this optical module 51 to a commercially available phase-contrast microscope, the observation device 5 can be constructed.

FIG. 17 is a diagram showing the configuration of an observation device 5A that is a modification of the observation device 5 of the fifth embodiment. Compared with the configuration of the observation device 5 shown in FIG. 16, the observation device 5A shown in FIG. 17 differs in the position where the polarizer 12 is provided. In this configuration example, the polarizer 12 is provided immediately before the patterned polarizer 14 . When the polarizer 12 is provided on the optical path between the observation object S and the patterned polarizer 14, even if the observation object S has birefringence, the interference image and the complex amplitude image are preferable. can be obtained. Also in this configuration, the polarizer 12, the patterned polarizer 14, the quarter-wave plate 15, the polarization camera 16, the lens 33 and the third optical system 40 can be put into a common housing to form the optical module 52. FIG. By attaching this optical module 52 to a commercially available phase-contrast microscope, the observation device 5A can be constructed.

FIG. 18 is a diagram showing the configuration of the observation device 6 of the sixth embodiment. Compared to the configuration of the observation device 5 shown in FIG. 16, the observation device 6 shown in FIG. The difference is that the unnecessary polarizer 12 is not provided. In this case, the orientation of the plane of polarization of the linearly polarized light output from the first region 14 a and the second region 14 b of the patterned polarizer 14 is set according to the orientation of the plane of polarization of the linearly polarized light output from the light source 11 .

FIG. 19 is a diagram showing the configuration of the observation device 7 of the seventh embodiment. The observation device 7 includes lenses 21 , 22 and 23 and a beam splitter 17 as a first optical system provided between the aperture 13 and the observation object S. The observation device 7 also includes a lens 23 as a second optical system provided between the observation object S and the patterned polarizer 14 . In this configuration, patterned polarizer 14 doubles as polarizer 12 and is provided in the optical path between beam splitter 17 and lens 23 . Light emitted from the light source 11 reaches the beam splitter 17 via the aperture 13 , lenses 21 and 22 and is reflected by the beam splitter 17 to the patterned polarizer 14 . The light passes through the first region 14a of the patterned polarizer 14 as linearly polarized light, passes through the lens 23, is applied to the observation object S, and is reflected by the bottom surface of the container containing the observation object S. FIG. The reflected light passes through lens 23 , patterned polarizer 14 and beam splitter 17 and enters quarter-wave plate 15 .

The observation apparatus described so far has a configuration capable of acquiring a two-dimensional complex amplitude image of the object S to be observed. However, as described below, the optical element constituting the second optical system 30 or the observation object S is scanned in a direction parallel to the optical axis of the second optical system 30, and the polarization camera 16 is detected at each scanning position. It is also possible to obtain a plurality of interference images by and create a three-dimensional complex amplitude image of the observed object S based on the plurality of interference images at each position of the scan. Although each configuration of the modified example of the observation device 1 of the first embodiment and the modified example of the observation device 7 of the seventh embodiment will be described below, the modified examples of the observation device of the other embodiments may also be configured. can.

FIG. 20 is a diagram showing the configuration of an observation device 1B that is a modification of the observation device 1 of the first embodiment. Compared with the configuration of the observation device 1 shown in FIG. 1, the observation device 1B shown in FIG. They are different in that respect.

FIG. 21 is a diagram showing the configuration of an observation device 1C that is a modification of the observation device 1 of the first embodiment. Compared with the configuration of the observation device 1 shown in FIG. 1, the observation device 1C shown in FIG. 19 is provided.

FIG. 22 is a diagram showing the configuration of an observation device 7B that is a modification of the observation device 7 of the seventh embodiment. Compared with the configuration of the observation device 7 shown in FIG. 19, the observation device 7B shown in FIG. They are different in that respect.

FIG. 23 is a diagram showing the configuration of an observation device 7C that is a modification of the observation device 7 of the seventh embodiment. Compared with the configuration of the observation device 7 shown in FIG. 19, the observation device 7C shown in FIG. The difference is that

In any observation device, the moving part 19 may be a linear stage, a piezo actuator, or a combination of a linear stage and a piezo actuator. By scanning the observation object S in the optical axis direction with the moving unit 19, or by scanning the second optical system 30 and the patterned polarizer 14 in the optical axis direction with the moving unit 19, the imaging surface of the polarization camera 16 A three-dimensional complex amplitude image of the observed object S can be created because the position conjugated to is scanned in the observed object S.

1, 1A, 1B, 1C, 2, 3, 3A, 4, 5, 5A, 6, 7, 7B, 7C... Observation device, 11... Light source, 12... Polarizer, 13... Aperture, 13a... Passing area, 13b 14: first region 14b: second region 15: quarter-wave plate 16: polarization camera 17: beam splitter 18: analysis unit 19: moving unit 20... First optical system, 30... Second optical system, 40... Third optical system, 51, 52... Optical module.

Claims (18)

a light source that outputs spatially incoherent light;
an aperture that has a passage area through which light passes, and that selectively passes and outputs light that has reached the passage area out of the light output from the light source;
a first optical system that receives the light output from the aperture and forms a Fourier transform image of the light output from the aperture;
Light output from the first optical system is input to an observation object placed at a position where a Fourier transform image is formed by the first optical system, and light output from the observation object is input, and the observation is performed. a second optical system that forms a Fourier transform image of the output light from the object;
A polarizer arranged on an optical path from the light source to a position where a Fourier transform image is formed by the second optical system, and for outputting input light as linearly polarized light;
The second optical system is arranged at a position where a Fourier transform image is formed by the second optical system, and has a first area corresponding to the passing area of the aperture and a second area other than the first area. selectively output linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light among the light input to the first region from the second optical system a patterned polarizer that selectively outputs linearly polarized light having a plane of polarization of 35° to 55° relative to the plane of polarization of the input light among the light that has entered the second region from
a third optical system that receives the light output from the patterned polarizer and forms a Fourier transform image of the output light from the patterned polarizer;
a quarter-wave plate arranged on the optical path of the third optical system to circularly polarize the light output from the first region and the second region of the patterned polarizer in different rotational directions;
having an imaging surface arranged at a position where a Fourier transform image is formed by the third optical system, and inputting two lights circularly polarized in different rotational directions by the quarter-wave plate; A polarization camera that acquires an interference image on the imaging plane for each component of the polarization plane of
an analysis unit that creates a complex amplitude image of the observed object based on interference images for each of three or more polarization plane components acquired by the polarization camera;
Observation device comprising. a light source that outputs spatially incoherent linearly polarized light;
an aperture that has a passage area through which light passes, and that selectively passes and outputs light that has reached the passage area out of the light output from the light source;
a first optical system that receives the light output from the aperture and forms a Fourier transform image of the light output from the aperture;
Light output from the first optical system is input to an observation object placed at a position where a Fourier transform image is formed by the first optical system, and light output from the observation object is input, and the observation is performed. a second optical system that forms a Fourier transform image of the output light from the object;
The second optical system is arranged at a position where a Fourier transform image is formed by the second optical system, and has a first area corresponding to the passing area of the aperture and a second area other than the first area. selectively output linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light among the light input to the first region from the second optical system a patterned polarizer that selectively outputs linearly polarized light having a plane of polarization of 35° to 55° relative to the plane of polarization of the input light among the light that has entered the second region from
a third optical system that receives the light output from the patterned polarizer and forms a Fourier transform image of the output light from the patterned polarizer;
a quarter-wave plate arranged on the optical path of the third optical system to circularly polarize the light output from the first region and the second region of the patterned polarizer in different rotational directions;
having an imaging surface arranged at a position where a Fourier transform image is formed by the third optical system, and inputting two lights circularly polarized in different rotational directions by the quarter-wave plate; A polarization camera that acquires an interference image on the imaging plane for each component of the polarization plane of
an analysis unit that creates a complex amplitude image of the observed object based on interference images for each of three or more polarization plane components acquired by the polarization camera;
Observation device comprising. The first optical system and the second optical system have a common portion for inputting and outputting light with respect to the observation object.
The viewing device according to claim 1 or 2. wherein the second optical system includes a relay optical system;
The observation device according to any one of claims 1 to 3. The polarization camera has a structure in which a plurality of pixels are arranged two-dimensionally on the imaging plane, and acquires a two-dimensional interference image.
The observation device according to any one of claims 1 to 4. The polarization camera has a structure in which a plurality of pixels are arranged one-dimensionally on the imaging plane, and acquires a one-dimensional interference image.
The observation device according to any one of claims 1 to 5. Acquiring a two-dimensional interference image of the observation target by relatively moving the observation target in a direction different from the arrangement direction of the plurality of pixels on the imaging plane of the polarization camera;
The observation device according to claim 6. scanning an optical element constituting the second optical system or the observation object in a direction parallel to the optical axis of the second optical system;
the polarization camera acquires an interference image at each position of the scan;
The analysis unit creates a three-dimensional complex amplitude image of the observation object based on the interference image acquired by the polarization camera at each position of the scanning.
An observation device according to any one of claims 1 to 7. having a first area and a second area other than the first area, relative to the plane of polarization of the input light from the second optical system input to the first area from −10° to Linearly polarized light having a plane of polarization of +10° is selectively output, and the plane of polarization of the light input from the second optical system to the second region is 35° to 55° relative to the plane of polarization of the input light. a patterned polarizer that selectively outputs linearly polarized light having a plane of polarization of °;
a quarter-wave plate that converts the light output from the first region and the second region of the patterned polarizer to circularly polarized light in different rotational directions;
A polarizing camera having an imaging plane for inputting two lights circularly polarized in different rotational directions by the quarter-wave plate, and acquiring an interference image on the imaging plane for each component of three or more polarization planes. and,
Optical module with Further comprising a polarizer arranged in front of the patterned polarizer for outputting input light to the patterned polarizer as linearly polarized light,
The optical module according to claim 9. Output spatially incoherent light from the light source,
using an aperture having a light-passing region to selectively pass through and output the light that has reached the light-passing region, out of the light output from the light source;
forming a Fourier transform image of the light output from the aperture by a first optical system for inputting the light output from the aperture;
A second optical system for inputting light output from the observation object by inputting light from the first optical system to the observation object arranged at a position where the Fourier transform image is formed by the first optical system. forming a Fourier transform image of output light from the observed object by a system;
A polarizer arranged on an optical path from the light source to a position where a Fourier transform image is formed by the second optical system outputs the input light as linearly polarized light,
A patterned polarizer having a first region corresponding to the passing region of the aperture and a second region other than the first region arranged at a position where a Fourier transform image is formed by the second optical system, the second selectively outputting linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light among the light input from the optical system to the first region; selectively outputting linearly polarized light having a plane of polarization of 35° to 55° relative to the plane of polarization of the input light among the light input from the optical system to the second region;
forming a Fourier transform image of the light output from the patterned polarizer by a third optical system for inputting the light output from the patterned polarizer;
Circularly polarized light output from the first region and the second region of the patterned polarizer is rotated in different directions by a quarter-wave plate arranged on the optical path of the third optical system;
Two lights circularly polarized in different rotational directions by the quarter-wave plate are inputted by a polarization camera having an imaging surface arranged at a position where a Fourier transform image is formed by the third optical system, Acquiring an interference image on the imaging plane for each of three or more polarization plane components,
creating a complex amplitude image of the observed object based on interference images for each of three or more polarization plane components acquired by the polarization camera;
Observation method. outputting spatially incoherent linearly polarized light from a light source,
using an aperture having a light-passing region to selectively pass through and output the light that has reached the light-passing region, out of the light output from the light source;
forming a Fourier transform image of the light output from the aperture by a first optical system for inputting the light output from the aperture;
A second optical system for inputting light output from the observation object by inputting light from the first optical system to the observation object arranged at a position where the Fourier transform image is formed by the first optical system. forming a Fourier transform image of output light from the observed object by a system;
A patterned polarizer having a first region corresponding to the passing region of the aperture and a second region other than the first region arranged at a position where a Fourier transform image is formed by the second optical system, the second selectively outputting linearly polarized light having a plane of polarization of −10° to +10° relative to the plane of polarization of the input light among the light input from the optical system to the first region; selectively outputting linearly polarized light having a plane of polarization of 35° to 55° relative to the plane of polarization of the input light among the light input from the optical system to the second region;
forming a Fourier transform image of the light output from the patterned polarizer by a third optical system for inputting the light output from the patterned polarizer;
Circularly polarized light output from the first region and the second region of the patterned polarizer is rotated in different directions by a quarter-wave plate arranged on the optical path of the third optical system;
Two lights circularly polarized in different rotational directions by the quarter-wave plate are inputted by a polarization camera having an imaging surface arranged at a position where a Fourier transform image is formed by the third optical system, Acquiring an interference image on the imaging plane for each of three or more polarization plane components,
creating a complex amplitude image of the observed object based on interference images for each of three or more polarization plane components acquired by the polarization camera;
Observation method. The first optical system and the second optical system have a common portion for inputting and outputting light with respect to the observation object.
The observation method according to claim 11 or 12. wherein the second optical system includes a relay optical system;
The observation method according to any one of claims 11 to 13. The polarization camera has a structure in which a plurality of pixels are arranged two-dimensionally on the imaging plane, and acquires a two-dimensional interference image.
The observation method according to any one of claims 11 to 14. The polarization camera has a structure in which a plurality of pixels are arranged one-dimensionally on the imaging plane, and acquires a one-dimensional interference image.
The observation method according to any one of claims 11 to 15. Acquiring a two-dimensional interference image of the observation target by relatively moving the observation target in a direction different from the arrangement direction of the plurality of pixels on the imaging plane of the polarization camera;
The observation method according to claim 16. scanning an optical element constituting the second optical system or the observation object in a direction parallel to the optical axis of the second optical system;
obtaining an interference image at each position of the scan with the polarization camera;
creating a three-dimensional complex amplitude image of the observed object based on the interference images acquired by the polarization camera at each position of the scan;
The observation method according to any one of claims 11 to 17.

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