Polarization imaging device

Abstract

The present invention provides a polarization imaging device capable of, even when a white light is used as a light source, performing measurement in a broadband wavelength range, i.e., color imaging. This invention provides a polarization imaging device comprising, in the order starting from an imaging object side, a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element having a grating period shorter than the grating period of the first polarization diffraction grating element, and a light receiving element, and preferably a polarization imaging device comprising, in the order starting from an imaging object side, a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element having a grating period shorter than the grating period of the first polarization diffraction grating element, an image-forming position correction element, and a light receiving element.

Description

[Technical Field]

[0001] The present invention relates to a polarization imaging device having, in order from an imaging target, a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element, and a light receiving element, preferably a polarization imaging device having a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element, an imaging position correction element, and a light receiving element. [Background technology]

[0002] Polarization, one of the parameters of light waves, changes significantly when it interacts with a material, so polarimetry can be used to obtain information about that material. For this reason, polarimetry is used in a variety of fields, including medicine and sensing.

[0003] Various techniques for measuring the polarization state have been reported for a long time. The most common polarization measurement techniques are the rotating analyzer method and the rotating retarder method, which use a rotating polarizer and wave plate. These methods observe the time waveform of light intensity corresponding to the polarization state of the incident light while rotating the polarizing element. The obtained time waveform is then subjected to Fourier analysis to reconstruct the Stokes parameters. This method has a long history of research and is characterized by high measurement accuracy due to various error reduction measures. However, because the information required to reconstruct the Stokes parameters is obtained multiple times while rotating the polarizing element over time, this method is not suitable for objects whose polarization state changes over time. Considering the application of polarimetry to medical devices, remote sensing, and other applications, there is a great need to measure the polarization state of dynamic objects, and snapshot measurements of the spatial polarization distribution are required.

[0004] Prior to the present invention, there have been several precedents for polarimetry using a polarization camera that enables snapshot measurement of the spatial distribution of polarized light. One example is to distribute wave plates or polarizers with their optical axis orientations divided into four directions on a photodetector array, and assign measurements equivalent to the rotating analyzer method or the rotating retarder method to every four pixels (see Non-Patent Documents 1 and 2). This method does not require a mechanical moving part to rotate the polarizer, and furthermore, the information necessary to obtain the Stokes parameters can be obtained by acquiring a single image, enabling static, snapshot-based imaging polarization measurement. However, the photodetector array and the polarizer array must be precisely aligned, which makes fabrication difficult. Furthermore, discontinuities in the phase difference at the boundaries of the polarizer array can potentially produce diffracted light, which is undesirable for measurement.

[0005] Another example of previous research that enables snapshot polarization imaging is an imaging polarimeter using a polarized Savart plate that utilizes spatial carriers during polarization interference (Non-Patent Document 3). This method does not suffer from the effects of diffraction that occur with the array element described above. However, this method requires expensive optical elements such as a Savart plate, which makes it costly.

[0006] The inventors, some of whom are the same as the inventors of the present application, have proposed an imaging device that overcomes this difficulty (Non-Patent Document 4). That is, they proposed a polarization imaging device that does not require any mechanically moving parts and is capable of snapshot polarization imaging measurement, a polarization imaging device that does not require highly accurate alignment of the polarization elements, and more particularly, a polarization imaging device that is relatively inexpensive. However, even with this imaging device, if white light is used as the light source, the image is separated into wavelengths due to the influence of wavelength dispersion caused by the diffraction grating, so if the object to be imaged has a two-dimensional size, measurements can only be made within a narrow wavelength range. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] T. Sato, T. Araki, Y. Sasaki, T. Tsuru, T. Tadokoro, and S. Kawakami, “Compact ellipsometer employing a static polarizer module with arrayed polarizer and wave-plate elements,” Appl. Opt. 46, 4963-4967 (2007). [Non-patent document 2] G. Myhre, WL Hsu, A. Peinado, C. LaCasse, N. Brock, RA Chipman, and S. Pau, “Liquid crystal polymer full-stokes division of focal plane polarimeter,” Opt. Express 20, 27393-27409 (2012). [Non-patent document 3] H. Luo, K. Oka, E. DeHoog, M. Kudenov, J. Schiewgerling, and EL Dereniak, “Compact and miniature snapshot imaging polarimeter,” Appl. Opt. 47, 4413-4417 (2008). [Non-patent document 4] K. Noda, R. Momosaki, J. Matsubara, M. Sakamoto, T. Sasaki, N. Kawatuki, K. Goto, and H. Ono, “Polarization imaging using an anisotropic diffraction grating and liquid crystal retarders”, Appl. Opt. 57, 8870-8875 (2018). Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a polarization imaging device that is capable of measurement over a wide wavelength range, that is, capable of color imaging, even when white light is used as a light source. [Means for solving the problem]

[0009] The present inventors have discovered the following inventions. <1> A polarization imaging device comprising, in order from the imaging target, a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element having a grating period shorter than the grating period of the first polarization diffraction grating element, and a light receiving element. <2> the above <1> In the above, it is preferable to further include an imaging position correction element on the light receiving element side (rear side) of the second polarization diffraction grating element and on the image pickup target side (front side) of the light receiving element. <3> the above <2> In the above, the imaging position correcting element is preferably a prism or a mirror.

[0010] <4> the above <1> ~ <3> In any one of the above, the first and second polarization grating elements preferably have polarization gratings having a plurality of grating vectors oriented in different directions, and at least the anisotropic orientation or birefringence of the grating vectors is periodically modulated. <5> the above <1> ~ <4> In any of the above, the first and second polarization grating elements may have polarization gratings that spatially separate information on the Stokes parameters of the incident light according to the anisotropic orientation and birefringence distribution, and convert the information into intensity information.

[0011] <6> the above <1> ~ <5> In any of the above, the first and / or second polarization grating elements preferably include a polarization grating having a photoreactive polymer film having photoreactive side chains that undergo at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization. <7> the above <1> ~ <6> In any of the above, the first and / or second polarization grating elements preferably include a polarization grating consisting solely of a photoreactive polymer film having photoreactive side chains that undergo at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization. <8> the above <1> ~ <7> In any one of the above, the first and / or second polarization grating element is I) a first transparent substrate layer; and II) A first photoreactive polymer film having a first photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization. The polarization grating may include a polarization grating having:

[0012] <9> the above <8> wherein the first and / or second polarization grating element is III) a second transparent substrate layer; and IV) a second photoreactive polymer film having a second photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization; and It is preferable that the II) first photoreactive polymer film and the IV) second photoreactive polymer film are arranged facing each other, and that a polarization diffraction grating is included in which a (B) low molecular weight liquid crystal layer is arranged between the II) first film and the IV) second film.

[0013] <10> the above <6> ~ <9> In any of the above, a polarization diffraction grating is preferably used which exposes a photoreactive polymer film to a desired polarized light by interference exposure, thereby forming an arbitrary diffraction pattern in the polymer thin film, and spatially separates information on the Stokes parameters of light incident on the polymer thin film according to the anisotropic orientation and birefringence distribution formed in the polymer thin film, and converts it into intensity information. <11> the above <1> ~ <10> In any of the above, the first and / or second polarization grating element preferably has a polarization grating with good diffraction efficiency for ±1st-order light.

[0014] <12> the above <6> ~ <11> In any one of the above, the photoreactive polymer film is represented by the following formulas (1) to (6): (In the formula, A, B, and D each independently represent a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group; T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group; Y1 represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by 2 to 6 identical or different rings selected from the substituents thereof being bonded via a bonding group B, and hydrogen atoms bonded thereto may each independently be substituted with -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; Y2 is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, and hydrogen atoms bonded thereto may each independently be substituted with -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or has the same definition as Y1; X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, Xs may be the same or different; Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and hydrogen atoms bonded thereto may each independently be substituted with -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; q1 and q2 are one 1 and the other 0; q3 is 0 or 1; P and Q each independently represent a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof; provided that when X is -CH=CH-CO-O- or -O-CO-CH=CH-, P or Q on the side to which -CH=CH- is bonded is an aromatic ring, and when the number of Ps is 2 or more, the Ps may be the same or different, and when the number of Qs is 2 or more, the Qs may be the same or different; l1 is 0 or 1; l2 is an integer between 0 and 2; When l1 and l2 are both 0, if T is a single bond, A also represents a single bond; When l1 is 1, if T is a single bond, B also represents a single bond; H and I are each independently a divalent group selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and combinations thereof. It is preferable to use a photoreactive polymer having any one photoreactive side chain selected from the group consisting of:

[0015] [ka]

[0016] <13> the above <6> ~ <12> In any one of the above, the photoreactive polymer film is represented by the following formulas (7) to (10): (In the formula, A, B, and D each independently represent a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y1 represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by 2 to 6 identical or different rings selected from the substituents thereof being bonded via a bonding group B, and hydrogen atoms bonded thereto may each independently be substituted with -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, Xs may be the same or different; l represents an integer from 1 to 12; m represents an integer of 0 to 2, and m1 and m2 represent integers of 1 to 3; n represents an integer of 0 to 12 (provided that when n=0, B is a single bond); Y2 is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, and hydrogen atoms bonded thereto may each independently be substituted with -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or has the same definition as Y1. It is preferable to use a photoreactive polymer having any one photoreactive side chain selected from the group consisting of:

[0017] [ka]

[0018] <14> the above <6> ~ <12> In any one of the above, the photoreactive polymer film is represented by the following formulas (11) to (13): (In the formula, each A independently represents a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, Xs may be the same or different; l represents an integer of 1 to 12, m represents an integer of 0 to 2, and m1 represents an integer of 1 to 3; R represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and the hydrogen atoms bonded thereto each independently represent -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms, or represent a hydroxy group or an alkoxy group having 1 to 6 carbon atoms). It is preferable to use a photoreactive polymer having any one photoreactive side chain selected from the group consisting of:

[0019] [ka]

[0020] <15> the above <6> ~ <12> In any one of the above, the photoreactive polymer film is represented by the following formula (14) or (15): (In the formula, each A independently represents a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y1 represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by 2 to 6 identical or different rings selected from the substituents thereof being bonded via a bonding group B, and hydrogen atoms bonded thereto may each independently be substituted with -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; l represents an integer from 1 to 12, and m1 and m2 represent integers from 1 to 3. It is preferable to use a photoreactive polymer having a photoreactive side chain represented by the formula:

[0021] [ka]

[0022] <16> the above <6> ~ <12> In any one of the above, the photoreactive polymer film is represented by the following formula (16) or (17) (wherein A represents a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, Xs may be the same or different; l represents an integer from 1 to 12, and m represents an integer from 0 to 2. It is preferable to use a photoreactive polymer having a photoreactive side chain represented by the formula:

[0023] [ka]

[0024] <17> the above <6> ~ <12> In any one of the above, the photoreactive polymer film is represented by the following formula (18) or (19): (In the formula, A and B each independently represent a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y1 represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by 2 to 6 identical or different rings selected from the substituents thereof being bonded via a bonding group B, and hydrogen atoms bonded thereto may each independently be substituted with -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; q1 and q2 are one 1 and the other 0; l represents an integer from 1 to 12, and m1 and m2 represent integers from 1 to 3; R1 represents a hydrogen atom, -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms. It is preferable that the photosensitive material has a photoreactive polymer having a photosensitive side chain selected from the group consisting of:

[0025] [ka]

[0026] <18> the above <6> ~ <12> In any one of the above, the photoreactive polymer film is represented by the following formula (20): (In the formula, A represents a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y1 represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by 2 to 6 identical or different rings selected from the substituents thereof being bonded via a bonding group B, and hydrogen atoms bonded thereto may each independently be substituted with -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, Xs may be the same or different; It is preferable to use a photoreactive polymer having a photoreactive side chain represented by the formula (I represents an integer of 1 to 12, and m represents an integer of 0 to 2).

[0027] [ka] [Effects of the Invention]

[0028] The present invention provides a polarization imaging device that is capable of measurement over a wide wavelength range, that is, capable of color imaging, even when white light is used as a light source. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a diagram showing an outline of the anisotropic spatial distribution and diffraction characteristics of a polarization diffraction grating used in the present application. [Figure 2] FIG. 1 is a diagram showing a schematic of white polarized light imaging. [Figure 3] FIG. 1 is a diagram showing a more specific outline of a polarization imaging device according to the present invention. [Figure 4]FIG. 10 shows an image captured using a scarab beetle as a subject and the polarization imaging device used in the examples, which is the result of imaging measurement, an image separated into RGB, and the spatial distribution of the Stokes parameter S3 calculated from them. DETAILED DESCRIPTION OF THE INVENTION

[0030] <Polarization imaging device> The present application provides a polarization imaging device having, in order from an imaging target, a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element, and a light receiving element, preferably a polarization imaging device having a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element, an imaging position correction element, and a light receiving element. In particular, the polarization imaging device of the present application arranges a second polarization grating element having a grating period (second grating period) shorter than the grating period (first grating period) of the first polarization grating element closer to the light receiving element than the first polarization grating element, thereby making it possible to reconcentrate the wavelength dispersion (chromatic dispersion) generated by the first polarization grating element at the light receiving element, which is the imaging position, and thereby achieving color imaging.

[0031] The principle of the polarization imaging device of the present invention will be briefly explained. First, we will explain how to obtain the Stokes parameters using a polarization grating. Figure 1 shows an outline of the anisotropic spatial distribution and diffraction characteristics of the polarization diffraction grating used in the present invention. The polarization diffraction grating used in the present invention is distributed so that the orientation of the optical axis rotates with respect to the grating direction. When light is transmitted through this polarization diffraction grating, the left and right circularly polarized components that make up the incident light are separated and diffracted in the ±1st order light directions, respectively. The intensity of the ±1st order light is expressed as I RCP and I LCP Then, S3 can be calculated by the following formula I.

[0032]

number

[0033] However, when white light is transmitted through this principle, the diffraction angle is wavelength dependent, resulting in angular separation for each wavelength. For this reason, when a measurement target has a spatial extent, the images overlap in a spatially shifted state, making accurate polarization analysis impossible.

[0034] The principle of white light imaging is described below. As mentioned above, when a single polarization grating is used, the image is separated into individual wavelengths due to the effects of wavelength dispersion. Therefore, two types of polarization gratings with different grating periods are used to recombine the light waves separated into each wavelength at the imaging position. Figure 2 shows a schematic diagram of white light polarization imaging.

[0035] In FIG. 2, a first polarization grating element PG1 and a second polarization grating element PG2 having a grating period different from that of the first polarization grating element are arranged in this order from the imaging target (not shown). First, white light incident on the first polarization grating element PG1 is separated into left and right circularly polarized components, which are diffracted according to the diffraction angle of each wavelength. The dispersed diffracted light is then incident on the second polarization grating element PG2, which has a shorter grating period than PG1, so that it is reconverged at the camera position. These two diffraction gratings make it possible to reconverge the separated wavelengths. However, since the point where the light is reconverged is close to the optical axis of the incident light, the images of the ±1st order light overlap. Therefore, a prism is used to control the light wave propagation direction so that the ±1st order light does not overlap at the imaging position of the camera's light receiving unit. This makes it possible to perform polarization imaging of a white light source.

[0036] A more specific schematic diagram of the polarization imaging device of the present invention is shown in FIG. In FIG. 3, arranged in order from the object to be imaged are a lens, a first polarization grating element PG1, a second polarization grating element PG2 having a grating period different from that of the first polarization grating element, a prism, and a camera. In order to cut the zero-order component of the light emitted from the first polarization grating element PG1, a mask such as black aluminum foil may be applied near the center of the optical axis of the second polarization grating element PG2.

[0037] First, light reflected from the sample passes through a lens element and enters a first polarization grating element, where it is separated into left- and right-circularly polarized components and diffracted according to the diffraction angle of each wavelength. A second polarization grating element with a shorter grating period than the first grating is placed to reconverge the dispersed diffracted light at the camera position (lens imaging plane). At this point, color imaging is made possible by placing an imaging position correction element such as a prism to prevent the diffracted light separated into ±1st-order light from overlapping on the imaging plane.

[0038] The polarization imaging device of the present application may include elements other than those described above, if desired. Elements other than those mentioned above include, but are not limited to, elements necessary for an imaging device, such as a lens group that replaces a lens and a field stop.

[0039] The present invention provides a polarization imaging device that includes a polarization grating element. Polarization, the property of the electric field vector locus of electromagnetic waves being polarized, is a widely used characteristic of electromagnetic waves. When electromagnetic waves interact with matter (through reflection, scattering, absorption, etc.), the polarization state of the electromagnetic waves changes, and this polarization change contains various information specific to the material. In other words, by measuring the polarization characteristics of a subject, it is possible to investigate material-specific information non-contact and non-destructively. The polarization imaging device proposed in this application can perform snapshot imaging measurements of the spatial distribution of the Stokes parameters (parameters that describe the polarization state) of scattered light from a subject.

[0040] <Polarization grating element> The polarization imaging device of the present application has first and second polarization grating elements, specifically polarization grating elements whose optical anisotropy is periodically modulated. The principle of Stokes parameter measurement using the polarization grating elements will be described below. The polarization state of an electromagnetic wave can be expressed by a Stokes vector consisting of four elements (S0, S1, S2, S3). Here, S0 is the total light intensity, S1 is the difference between the 0° linear polarization component and the 90° linear polarization component, S2 is the difference between the 45° linear polarization component and the -45° linear polarization component, and S3 is the difference between the right-handed circular polarization component and the left-handed circular polarization component, and these are called the Stokes parameters. When the amplitude ratio angle and phase difference between the 0-degree linearly polarized component and the 90-degree linearly polarized component are respectively Ψ and Δ, each Stokes parameter is defined by the following formula (1).

[0041]

number

[0042] By determining these four elements from the intensity information of light reflected, scattered, and transmitted from the subject, the polarization characteristics of the subject can be clarified. The polarization imaging device of this application can also measure these Stokes parameters by capturing images three times. The polarization detection principle of this device is based on a polarization diffraction grating element whose optical anisotropy is periodically modulated. Before describing the configuration of the device, the diffraction characteristics of a polarization diffraction grating fabricated by polarization hologram recording will be described.

[0043] Generally, in polarization-sensitive recording materials, the direction of optical anisotropy and the magnitude of birefringence are recorded according to the polarization direction and polarization ellipticity of the irradiated polarized light. Consider the case where two circularly polarized lights, one right-handed and one left-handed, with equal amplitudes, are interfered at a certain crossing angle, and the resulting optical field is irradiated onto a polarized recording material (unless otherwise specified, this case is referred to as orthogonal circular polarization interference (OC interference)). In this case, assuming that the direction and magnitude of the induced anisotropy depend on the polarization direction and light intensity, the Jones matrix representing the distribution of the induced anisotropy is expressed by the following equation (2): where Δγ = πΔnd / λ, Δn is the maximum value of polarization-induced birefringence, d is the film thickness of the recording material, and λ is the wavelength of the diffracted light.

[0044] Furthermore, the following equation (3) can be obtained by expanding equation (2). From equation (3), the intensity of the diffracted light for the incident polarized light given by equation (4) can be calculated as T OC ± is required. Therefore, it can be seen that the diffracted light intensity of the anisotropic grating formed by OC recording due to OC interference depends on the phase difference of the incident light. For simplicity, this grating will be referred to as the OC grating hereafter.

[0045]

number

[0046] As described above, the polarization diffraction grating formed in the polarization recording material by polarization holographic recording exhibits diffraction characteristics that depend on the polarization state of the incident light, making it possible to spatially separate the polarization information of the incident light as intensity information.

[0047] It is preferable that the polarization diffraction grating has a good diffraction efficiency for ±1st-order light. In an OC grating, the ideal phase difference that provides the best diffraction efficiency for ±1st-order light can be obtained from the above formula (4). Specifically, for an OC grating, the diffraction efficiency should be 5% or more, i.e., the phase difference (δ=2πΔnd / λ) should be in the range of 0.448+2πm to 5.82+2πm (m: natural number), preferably the diffraction efficiency should be 50% or more, i.e., the phase difference (δ=2πΔnd / λ) should be in the range of 1.57+2πm to 4.71+2πm (m: natural number), and ideally the diffraction efficiency should be 100%, i.e., the phase difference (δ=2πΔnd / λ) should be 3.14+2πm (m: natural number).

[0048] The polarization grating element can be prepared as follows. That is, the polarization diffraction grating element preferably includes a polarization diffraction grating having a photoreactive polymer film having photoreactive side chains that undergo at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization. Furthermore, it is preferable that the polarization diffraction grating element includes a polarization diffraction grating made only of a photoreactive polymer film. In this case, since it is necessary to improve the diffraction efficiency of ±1st-order light obtained from the diffraction pattern formed in the photoreactive polymer film, it is preferable that the photoreactive polymer used in the photoreactive polymer film is a polymer that can induce a large phase difference, specifically a phase difference in the above-mentioned range, by interference exposure of the desired polarized light.

[0049] The polarization grating element is I) a first transparent substrate layer; and II) A first photoreactive polymer film having a first photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization. The polarization grating may include a polarization grating having:

[0050] The polarization grating element is III) a second transparent substrate layer; and IV) a second photoreactive polymer film having a second photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization; and It is preferable that the II) first photoreactive polymer film and the IV) second photoreactive polymer film are arranged facing each other, and that a polarization diffraction grating is included in which a (B) low molecular weight liquid crystal layer is arranged between the II) first film and the IV) second film.

[0051] <<First and Second Transparent Substrate Layers>> The first and second transparent substrate layers are made of a transparent substrate. The transparent substrate may be made of, for example, glass or plastics such as acrylic or polycarbonate, depending on the properties of the polarization imaging device to be used. For example, the transparent substrate should have the property of transmitting polarized ultraviolet light.

[0052] <<(B) Low molecular liquid crystal layer>> Here, the low molecular weight liquid crystal contained in the (B) low molecular weight liquid crystal layer can be a nematic liquid crystal or a ferroelectric liquid crystal that has been conventionally used in liquid crystal display elements. Specifically, examples of low molecular weight liquid crystals include cyanobiphenyls such as 4-cyano-4'-n-pentylbiphenyl and 4-cyano-4'-n-phenethyloxybiphenyl; cholesteryl esters such as cholesteryl acetate and cholesteryl benzoate; carbonates such as 4-carboxyphenylethyl carbonate and 4-carboxyphenyl-n-butyl carbonate; phenyl esters such as benzoic acid phenyl ester and phthalic acid biphenyl ester; Schiff bases such as benzylidene-2-naphthylamine and 4'-n-butoxybenzylidene-4-acetylaniline; benzidines such as N,N'-bisbenzylidenebenzidine and p-dianisalbenzidine; 4,4'-azoxydianisole and 4,4'-di-n-butoxy Examples include, but are not limited to, azoxybenzenes such as azoxybenzene; and liquid crystals such as phenylcyclohexyl, terphenyl, and phenylbicyclohexyl types specifically shown below.

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] It is preferable to expose the above-mentioned photoreactive polymer film to a desired polarized light by interference exposure, thereby forming an arbitrary diffraction pattern in the polymer thin film, thereby forming a polarization diffraction grating that spatially separates the information on the Stokes parameters of light incident on the polymer thin film according to the anisotropic orientation and birefringence distribution formed in the polymer thin film and converts it into intensity information.

[0057] <<Photoreactive polymer film>> The above-mentioned photoreactive polymer film is preferably formed using a photoreactive polymer having a photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization. In this specification, photoreactivity refers to the property of causing either (A-1) photocrosslinking or (A-2) photoisomerization; or both of these reactions. The photoreactive polymer preferably has (A-1) a side chain that undergoes a photocrosslinking reaction.

[0058] The photoreactive polymer is a polymer that exhibits liquid crystallinity within a predetermined temperature range and has a photoreactive side chain. The photoreactive polymer preferably ii) reacts to light in the wavelength range of 250 nm to 450 nm and exhibits liquid crystallinity in the temperature range of 50 to 300°C. The photoreactive polymer preferably has iii) a photoreactive side chain that reacts to light in the wavelength range of 250 nm to 450 nm, particularly polarized ultraviolet light. The photoreactive polymer preferably has a mesogenic group because it exhibits liquid crystallinity in the temperature range of 50 to 300°C.

[0059] As described above, the photoreactive polymer has a photoreactive side chain that exhibits photoreactivity. The structure of the side chain is not particularly limited, but preferably has a structure that induces the reactions shown in (A-1) and / or (A-2) above, and has a structure that induces the (A-1) photocrosslinking reaction. The (A-1) structure that induces the photocrosslinking reaction is preferred because the structure after the reaction can stably maintain the orientation of the photoreactive polymer for a long period of time even if exposed to external stress such as heat. The side chain structure of the photoreactive polymer preferably has a rigid mesogen component, since this stabilizes the alignment of the liquid crystal.

[0060] Examples of mesogenic components include, but are not limited to, biphenyl groups, terphenyl groups, phenylcyclohexyl groups, phenylbenzoate groups, azobenzene groups, and the like.

[0061] Examples of the main chain structure of the photoreactive polymer include, but are not limited to, at least one selected from the group consisting of radical polymerizable groups such as hydrocarbons, (meth)acrylates, itaconates, fumarates, maleates, α-methylene-γ-butyrolactone, styrene, vinyl, maleimides, and norbornenes, and siloxanes. The side chain of the photoreactive polymer is preferably a side chain consisting of at least one of the following formulas (1) to (6).

[0062] [ka]

[0063] In the formula, A, B, and D each independently represent a single bond, -O-, -CH2-, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group; T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group; Y1 represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by 2 to 6 identical or different rings selected from the substituents thereof being bonded via a bonding group B, and hydrogen atoms bonded thereto may each independently be substituted with -COOR0 (wherein R0 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; Y2 is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, and hydrogen atoms bonded thereto may each independently be substituted with -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or has the same definition as Y1; X represents a single bond, -COO-, -OCO-, -N=N-, -CH=CH-, -C≡C-, -CH=CH-CO-O-, or -O-CO-CH=CH-, and when the number of X is 2, Xs may be the same or different; Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and hydrogen atoms bonded thereto may each independently be substituted with -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; q1 and q2 are one 1 and the other 0; q3 is 0 or 1; P and Q each independently represent a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof; provided that when X is -CH=CH-CO-O- or -O-CO-CH=CH-, P or Q on the side to which -CH=CH- is bonded is an aromatic ring, and when the number of Ps is 2 or more, the Ps may be the same or different, and when the number of Qs is 2 or more, the Qs may be the same or different; l1 is 0 or 1; l2 is an integer between 0 and 2; When l1 and l2 are both 0, if T is a single bond, A also represents a single bond; When l1 is 1, if T is a single bond, B also represents a single bond; H and I are each independently a divalent group selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and combinations thereof.

[0064] The side chain is preferably any one photoreactive side chain selected from the group consisting of the following formulas (7) to (10). wherein A, B, D, Y1, X, Y2, and R have the same definitions as above; l represents an integer from 1 to 12; m represents an integer of 0 to 2, and m1 and m2 represent integers of 1 to 3; n represents an integer of 0 to 12 (provided that when n=0, B is a single bond).

[0065] [ka]

[0066] The side chain is preferably any one photoreactive side chain selected from the group consisting of the following formulas (11) to (13). wherein A, X, l, m, m1 and R have the same definitions as above.

[0067] [ka]

[0068] The side chain is preferably a photoreactive side chain represented by the following formula (14) or (15). wherein A, Y1, l, m1 and m2 have the same definitions as above.

[0069] [ka]

[0070] The side chain is preferably a photoreactive side chain represented by the following formula (16) or (17). wherein A, X, l, and m have the same definitions as above.

[0071] [ka]

[0072] The side chain is preferably a photoreactive side chain represented by the following formula (18) or (19). (Wherein, A, B, Y1, and R1 have the same definitions as above. q1 and q2 are one 1 and the other 0; l represents an integer from 1 to 12, and m1 and m2 represent integers from 1 to 3;

[0073] [ka]

[0074] The side chain is preferably a photoreactive side chain represented by the following formula (20). wherein A, Y1, X, l and m have the same definitions as above.

[0075] [ka]

[0076] Furthermore, the component forming the photoreactive polymer film may contain a polymer having any one type of liquid crystalline side chain selected from the group consisting of the following formulas (21) to (31): For example, when the photoreactive side chain of the above-mentioned polymer forming the photoreactive polymer film does not have liquid crystallinity, or when the main chain of the above-mentioned polymer forming the photoreactive polymer film does not have liquid crystallinity, the component forming the photoreactive polymer film preferably has any one type of liquid crystalline side chain selected from the group consisting of the following formulas (21) to (31): wherein A, B, q1 and q2 have the same definitions as above; Y3 is a group selected from the group consisting of a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, and hydrogen atoms bonded to the group may each independently be substituted with -NO2, -CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; R3 represents a hydrogen atom, -NO2, -CN, -CH=C(CN)2, -CH=CH-CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms; l represents an integer of 1 to 12, m represents an integer of 0 to 2, provided that in formulas (23) and (24), the total of all m's is 2 or more, and in formulas (25) and (26), the total of all m's is 1 or more, and m1, m2, and m3 each independently represent an integer of 1 to 3; R2 represents a hydrogen atom, -NO2, -CN, a halogen group, a monovalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a nitrogen-containing heterocycle, an alicyclic hydrocarbon having 5 to 8 carbon atoms, an alkyl group, or an alkyloxy group; Z1 and Z2 each represent a single bond, -CO-, -CH2O-, -CH=N-, or -CF2-.

[0077] [ka]

[0078] <<Photoreactive polymer film manufacturing method>> The photoreactive polymer film can be produced by polymerizing a photoreactive side chain monomer having the photoreactive side chain, or, in some cases, copolymerizing the photoreactive side chain monomer with a monomer having a liquid crystalline side chain. For example, the film can be produced by referring to paragraphs

[0062] to

[0090] of WO2017 / 061536 (the entire contents of which are incorporated herein by reference).

[0079] <Lens element> The polarization imaging device of the present invention has a lens element. The lens element is not particularly limited as long as it has the function of forming an image on the light receiving element described below. <Imaging position correction element> The polarization imaging device of the present invention has an imaging position correction element. The imaging position correction element is not particularly limited as long as it has the function of correcting the imaging position on the light receiving element described below. Examples of the imaging position correction element include, but are not limited to, a prism (the angle of the prism can be changed appropriately depending on the elements used in the polarization imaging device of the present invention) and a mirror. <Photodetector> The polarization imaging device of the present invention has a light receiving element. The light receiving element is not particularly limited as long as it can acquire intensity information of each of the RGB components of each pixel.

[0080] By introducing an imaging unit (lens element, light receiving element, for example, a light receiving element array), imaging measurement can be performed without being limited to point measurement. Generally, to find the Stokes parameters, methods are used that measure the light intensity of the 0° linear polarization component, 90° linear polarization component, 45° linear polarization component, -45° linear polarization component, right-handed circular polarization component, and left-handed circular polarization component in equation (1), or Fourier analysis methods such as the rotating retarder method.However, these methods, in principle, require multiple measurements, and are therefore not suitable for measuring objects whose state changes over time. In contrast, the polarization imaging device of the present invention spatially separates the information required to measure the Stokes parameters and acquires it as intensity information, enabling snapshot polarization imaging measurement. Furthermore, by using first and second liquid crystal retarders with desired retardation response speeds, it is possible to measure even dynamic objects. Another feature is that it is inexpensive because it does not require expensive optical elements, including diffraction gratings.

[0081] The polarization imaging value of the present invention can measure two-dimensionally both dynamic and static objects, and therefore can be applied to a variety of fields, including, but not limited to, the medical field, the autonomous driving technology field, and the security field. The present invention will be specifically described below using examples, but the present invention is not limited to these examples. [Example]

[0082] <Fabrication of polarization diffraction grating> The recording material used was a photo-crosslinkable polymer liquid crystal (4-(4-methoxycinnamoyloxy)biphenyl side groups (P6CB)) represented by the following formula. P6CB was dissolved in dichloromethane and spin-coated onto a glass substrate to a film thickness of 300 nm. Two glass substrates coated with P6CB film were prepared and bonded together with the P6CB film facing each other to create an empty cell with a 9 μm gap. An ultraviolet laser beam with a wavelength of 325 nm emitted from a He-Cd laser was applied to the empty cell at 600 mJ / cm. 2 The film was irradiated with an exposure energy of 1000 kJ / cm. After irradiation, it was heat-treated in an oven at 150°C for 15 minutes, and after the heat treatment, low molecular weight liquid crystal ZLI4792 (manufactured by Merck) was injected into the cell to fabricate a cell-type OC grating. The diameter of the fabricated polarization diffraction grating was 8 mm. The obtained polarization diffraction grating has a function of periodically modulating optical anisotropy, specifically, the function of spatially separating right- and left-circularly polarized light into ±1st-order light directions.

[0083] [ka]

[0084] <Fabrication of polarization imaging device> A polarization imaging device was fabricated according to the schematic diagram of the polarization imaging device shown in FIG. Specifically, as shown in Fig. 3, the polarization imaging device was arranged, in order from the object to be imaged, as follows: lens, first polarization grating element PG1, second polarization grating element PG2, prism, and camera. A commercially available camera (Sony α6000) was used as the light receiving element. The first polarization grating PG1 and second polarization grating PG2 had grating periods of 27 µm and 3 µm, respectively. The prism angle was approximately 18°.

[0085] <Imaging measurement> In this example, imaging measurement was performed using a scarab beetle as the subject, which exhibits selective reflection characteristics for circularly polarized light. Figure 4 shows the captured image, the RGB separated image, and the spatial distribution of the Stokes parameter S3 calculated from them. The S3 spatial distribution of each image was calculated using the corresponding pixel intensity information of the RCP and LCP according to equation (1). The experimental results confirmed that the images were formed without separation for each wavelength. It is known that scarab beetle wings reflect LCP more strongly than RCP, and the results shown in Figure 4 are similar. Additionally, there are differences in the spatial distribution of S3 for each RGB component, and it can be seen that the above reflection characteristics are more pronounced at wavelengths around green. From these findings, it was demonstrated that S3 for each wavelength band can be calculated, albeit roughly, using this camera.

Claims

1. A polarization imaging device comprising, in order from an imaging target, a lens element, a first polarization diffraction grating element, a second polarization diffraction grating element having a grating period shorter than the grating period of the first polarization diffraction grating element, and a light receiving element.

2. 2. The polarization imaging device according to claim 1, further comprising an imaging position correction element located closer to the light receiving element than the second polarization diffraction grating element and closer to the imaging target than the light receiving element.

3. 3. The polarization imaging device according to claim 2, wherein the imaging position correcting element is a prism or a mirror.

4. The device according to any one of claims 1 to 3, wherein the first and second polarization grating elements have polarization gratings having a plurality of grating vectors oriented in different directions from each other, and at least the anisotropic orientation or birefringence of the grating vectors is periodically modulated.

5. The device according to any one of claims 1 to 4, wherein the first and second polarization grating elements have polarization gratings that spatially separate information on the Stokes parameters of the incident light according to the distribution of anisotropic orientation and birefringence, and convert the information into intensity information.

6. The device according to any one of claims 1 to 5, wherein the first and / or second polarization grating element comprises a polarization grating having a photoreactive polymer film having photoreactive side chains that undergo at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization.

7. The device according to any one of claims 1 to 5, wherein the first and / or second polarization grating element comprises a polarization grating consisting solely of a photoreactive polymer film having photoreactive side chains that undergo at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization.

8. the first and / or second polarization grating element: I) a first transparent substrate layer; and II) A first photoreactive polymer film having a first photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization.

8. The apparatus of claim 1, further comprising a polarization grating having:

9. the first and / or second polarization grating element: III) a second transparent substrate layer; and IV) a second photoreactive polymer film having a second photoreactive side chain that undergoes at least one reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization; and The device of claim 8, further comprising a polarization diffraction grating in which the first photoreactive polymer film (II) and the second photoreactive polymer film (IV) are arranged facing each other, and a low molecular weight liquid crystal layer (B) is arranged between the first film (II) and the second film (IV).

10. The device described in any one of claims 6 to 9 is a polarization diffraction grating that spatially separates information on the Stokes parameters of light incident on the polymer thin film according to the anisotropic orientation and birefringence distribution formed in the polymer thin film and converts it into intensity information by exposing the photoreactive polymer film to a desired polarized light and forming an arbitrary diffraction pattern in the polymer thin film.

11. The photoreactive polymer film is represented by the following formulas (1) to (6): (In the formula, A, B, and D each independently represent a single bond, —O—, or —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; S is an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group; T is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto may be replaced by a halogen group; Y １ represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and hydrogen atoms bonded thereto are each independently -COOR ０ (In the formula, R ０ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; Y ２ is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, and the hydrogen atoms bonded thereto are each independently -NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or Y １ represents the same definition as X represents a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═CH—, and when the number of X is 2, Xs may be the same or different; Cou represents a coumarin-6-yl group or a coumarin-7-yl group, and the hydrogen atoms bonded thereto are each independently —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; q1 and q2 are one 1 and the other 0; q3 is 0 or 1; P and Q each independently represent a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and a combination thereof; provided that when X is -CH=CH-CO-O- or -O-CO-CH=CH-, P or Q on the side to which -CH=CH- is bonded is an aromatic ring, and when the number of Ps is 2 or more, the Ps may be the same or different, and when the number of Qs is 2 or more, the Qs may be the same or different; l1 is 0 or 1; l2 is an integer from 0 to 2; When l1 and l2 are both 0, when T is a single bond, A also represents a single bond; When l1 is 1, when T is a single bond, B also represents a single bond; H and I are each independently a divalent group selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and combinations thereof. The device according to any one of claims 6 to 10, comprising a photoreactive polymer having any one photoreactive side chain selected from the group consisting of: 【Chemistry 1】

12. The photoreactive polymer film is represented by the following formulas (7) to (10): (In the formula, A, B, and D each independently represent a single bond, —O—, or —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y １ represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and hydrogen atoms bonded thereto are each independently -COOR ０ (In the formula, R ０ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; X represents a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═CH—, and when the number of X is 2, Xs may be the same or different; l represents an integer of 1 to 12; m represents an integer of 0 to 2, and m1 and m2 represent integers of 1 to 3; n represents an integer of 0 to 12 (provided that when n=0, B is a single bond); Y ２ is a group selected from the group consisting of a divalent benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, an alicyclic hydrocarbon having 5 to 8 carbon atoms, and combinations thereof, and the hydrogen atoms bonded thereto are each independently -NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; R represents a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, or Y １ (It has the same definition as The device according to any one of claims 6 to 11, comprising a photoreactive polymer having any one photoreactive side chain selected from the group consisting of: 【Chemistry 2】

13. The photoreactive polymer film is represented by the following formulas (11) to (13): (In the formula, each A is independently a single bond, —O—, or —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; X represents a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═CH—, and when the number of X is 2, Xs may be the same or different; l represents an integer of 1 to 12, m represents an integer of 0 to 2, and m1 represents an integer of 1 to 3; R represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and hydrogen atoms bonded thereto are each independently -COOR ０ (In the formula, R ０ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms, or represents a hydroxy group or an alkoxy group having 1 to 6 carbon atoms). The device according to any one of claims 6 to 11, comprising a photoreactive polymer having any one photoreactive side chain selected from the group consisting of: 【Transformation 3】

14. The photoreactive polymer film is represented by the following formula (14) or (15): (In the formula, each A is independently a single bond, —O—, or —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y １ represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and hydrogen atoms bonded thereto are each independently -COOR ０ (In the formula, R ０ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; l represents an integer of 1 to 12, and m1 and m2 represent integers of 1 to 3. The device according to any one of claims 6 to 11, comprising a photoreactive polymer having a photoreactive side chain represented by the formula: 【Chemistry 4】

15. The photoreactive polymer film is represented by the following formula (16) or (17) (wherein A is a single bond, —O—, —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; X represents a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═CH—, and when the number of X is 2, Xs may be the same or different; l represents an integer of 1 to 12, and m represents an integer of 0 to 2. The device according to any one of claims 6 to 11, comprising a photoreactive polymer having a photoreactive side chain represented by the formula: 【Transformation 5】

16. The photoreactive polymer film is represented by the following formula (18) or (19): (In the formula, A and B each independently represent a single bond, —O—, or —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y １ represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and hydrogen atoms bonded thereto are each independently -COOR ０ (In the formula, R ０ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; q1 and q2 are one 1 and the other 0; l represents an integer of 1 to 12, and m1 and m2 represent integers of 1 to 3; R １ is a hydrogen atom, -NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms).

12. The device according to claim 6, further comprising a photoreactive polymer having a photosensitive side chain selected from the group consisting of: 【Transformation 6】

17. The photoreactive polymer film is represented by the following formula (20): (Wherein, A is a single bond, —O—, —CH ２ represents -, -COO-, -OCO-, -CONH-, -NH-CO-, -CH=CH-CO-O-, or -O-CO-CH=CH-; Y １ represents a monovalent ring selected from a benzene ring, a naphthalene ring, a biphenyl ring, a furan ring, a pyrrole ring, and an alicyclic hydrocarbon having 5 to 8 carbon atoms, or a group formed by bonding 2 to 6 identical or different rings selected from the substituents thereof via a bonding group B, and hydrogen atoms bonded thereto are each independently -COOR ０ (In the formula, R ０ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), —NO ２ , -CN, -CH=C(CN) ２ , -CH=CH-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, or an alkyloxy group having 1 to 5 carbon atoms; X represents a single bond, —COO—, —OCO—, —N═N—, —CH═CH—, —C≡C—, —CH═CH—CO—O—, or —O—CO—CH═CH—, and when the number of X is 2, Xs may be the same or different; 12. The device according to claim 6, comprising a photoreactive polymer having a photoreactive side chain represented by the formula: (I represents an integer of 1 to 12, and m represents an integer of 0 to 2). 【Transformation 7】

Images