Miniature High-Energy-Efficient Diffraction Polarization Spectral Imaging Device and Its Polarization Spectrum Reconstruction Method

Abstract

The present invention relates to a polarization spectral imaging device and a polarization spectrum reconstruction method, and particularly to a micro high-efficiency diffraction polarization spectral imaging device and its polarization spectrum reconstruction method, which solve the technical problems of low energy utilization rate, low regulation accuracy and large size of the existing polarization spectral imaging device. The micro high-efficiency diffraction polarization spectral imaging device provided by the present invention directly and compactly integrates a diffraction spectral lens module, an electrorheological lens module and a polarization module by using a macro imaging module, which can reduce the spatial coupling distance and effectively improve the imaging quality; the diffraction spectral lens module realizes time-sharing spectral regulation through the electrorheological lens module, and the polarization module performs area array spatial division polarization regulation, and can directly obtain the polarization information of 0 degrees, 45 degrees, 90 degrees and 135 degrees under different spectral channels, avoiding the absorption effect of the traditional filter on the spectrum, improving the energy utilization rate, and also reducing the number of polarization regions and improving the regulation accuracy.

Description

Technical Field

[0001] The present invention relates to a polarization spectral imaging device and a polarization spectrum reconstruction method, and particularly to a micro high-efficiency diffractive polarization spectral imaging device and its polarization spectrum reconstruction method. Background Art

[0002] The polarization spectral imaging device integrates spectral, polarization and spatial dimensional information, and has received extensive attention in the fields of intelligent vision systems, autonomous navigation, micro-nano robots, and biomedicine. Traditional polarization spectral imaging devices mostly adopt a filter structure and a polarization response element. Due to the multiple filter and absorption effects of the light field energy, the energy utilization rate is low, and it is difficult to achieve the efficient acquisition and utilization of high-dimensional polarization spectral information. At the same time, the filter structure and polarization response element of the traditional polarization spectral structure mostly adopt mechanical control methods such as stepping motors to achieve the integration control of time-space and spectrum. Its control accuracy is low, the size is large, and it is difficult to meet the development requirements of miniaturization, high precision and portability of the polarization spectral imaging device. Therefore, it is urgent to develop a polarization spectral imaging device with high energy utilization rate, miniaturization, intelligent controllability and high precision to meet the technical development requirements of miniaturization, integration and multi-dimensional optical information perception in the intelligent information era. Summary of the Invention

[0003] The purpose of the present invention is to solve the technical problems of low energy utilization rate, low control accuracy and large size of the existing polarization spectral imaging device, and to provide a micro high-efficiency diffractive polarization spectral imaging device and its polarization spectrum reconstruction method.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A micro high-efficiency diffractive polarization spectral imaging device, characterized in that it includes a macro imaging module, a diffractive spectral lens module, an electro-rheological lens module, a polarization module and a detector module arranged in sequence along the transmission direction of the incident light beam, and an image processing module electrically connected to the detector module;

[0006] The macro imaging module includes N×N macro imaging lenses for coupling the incident light beam to form N×N incident parallel light beams, where N is an integer and 1≤N≤16;

[0007] The diffractive spectral lens module includes N×N diffractive spectral lens elements respectively corresponding to the N×N macro imaging lenses. Each diffractive spectral lens element is used to diffract the corresponding incident parallel light along its transmission direction to form M multi-spectral images located at different spatial positions, where M = N×N;

[0008] The electro-rheological lens module includes N×N electro-rheological lenses respectively corresponding to N×N diffractive spectral lens elements. The electro-rheological lenses use an electro-control time-sharing regulation method to regulate the focal lengths of M multi-spectral images formed by the corresponding diffractive spectral lens elements, so that the M multi-spectral images are sequentially located on the polarization module;

[0009] The polarization module includes N×N polarization elements respectively corresponding to N×N electro-rheological lenses; each polarization element includes a 2×2 polarization combination area composed of polarization areas of 0°, 45°, 90°, and 135°. The polarization module uses a planar array spatial-division polarization regulation method to respectively perform planar array detection of the 0° polarization information, 45° polarization information, 90° polarization information, and 135° polarization information of the M multi-spectral images, and a total of N×N sets of multi-spectral polarization image sets are obtained. Each set of multi-spectral polarization image sets includes M multi-spectral polarization images;

[0010] The detector module is used to detect and image the N×N sets of multi-spectral polarization image sets and send them to the image processing module. The detection imaging period of the detector module is consistent with the electro-control time-sharing regulation period of the electro-rheological lenses.

[0011] Furthermore, 2≤N≤16, and the N×N micro-imaging lenses are arranged in a planar array.

[0012] Furthermore, the detector module includes N×N detectors respectively corresponding to N×N polarization elements. Each detector is used to perform detection imaging of the M multi-spectral polarization images obtained by the corresponding polarization element. At this time, a four-quadrant detector is used for the detector.

[0013] Alternatively, the detector module directly uses a planar array camera.

[0014] Furthermore, the electro-rheological lenses use an externally applied voltage time-sharing regulation method to regulate the focal length.

[0015] Furthermore, the N×N diffractive spectral lens elements are arranged in a black light-blocking planar array structure;

[0016] The N×N electro-rheological lenses are arranged in a black light-blocking planar array structure;

[0017] The N×N polarization elements adopt a metal wire grid structure and are directly arranged on the detector module.

[0018] A polarization spectrum reconstruction method for the above-mentioned micro high-efficiency diffractive polarization spectrum imaging device is characterized in that it includes the following steps:

[0019] Step 1: After the incident light beam passes through the N×N micro-imaging lenses, it is coupled to form N×N incident parallel light beams and transmitted to the N×N diffractive spectral lens elements respectively;

[0020] Step 2: Each diffractive spectral lens element diffracts a beam of incident parallel light into M multi-spectral images located at different spatial positions along its transmission direction, and transmits them to the corresponding electro-rheological lens;

[0021] Step 3: Each electro-rheological lens respectively adjusts the focal lengths of its corresponding M multi-spectral images, so that the M multi-spectral images are sequentially located at the corresponding polarization elements;

[0022] Step 4: Each polarization element adjustment method respectively adjusts the polarization states of its corresponding M multi-spectral images to obtain the 0-degree polarization information, 45-degree polarization information, 90-degree polarization information, and 135-degree polarization information of the M multi-spectral images. Then, the detector module detects and images them and sends them to the image processing module, and a total of N×N sets of multi-spectral polarization image sets are obtained; each set of multi-spectral polarization image sets includes M multi-spectral polarization images, and each multi-spectral polarization image includes four polarization channels of 0 degrees, 45 degrees, 90 degrees, and 135 degrees;

[0023] Step 5: The image processing module respectively performs spatial correction, aberration correction, intensity correction, and denoising on the multi-spectral polarization images in the N×N sets of multi-spectral polarization image sets detected by the detector module in sequence, and then inputs them into the 3D U-net neural network model for spectral reconstruction to obtain a polarization spectral data cube, completing the polarization spectral reconstruction.

[0024] Further, Step 5 is specifically:

[0025] Step 5.1: Obtain the change coefficients of the magnification and rotation angle of different spectral channels in the multi-spectral polarization image, and then perform spatial correction on the four polarization channels of 0 degrees, 45 degrees, 90 degrees, and 135 degrees of each multi-spectral polarization image respectively through the following formula to obtain a multi-spectral polarization two-dimensional image with a consistent spatial size:

[0026]

[0027] Among them, represents the multi-spectral polarization two-dimensional image, is the abscissa of the pixel point in the multi-spectral polarization two-dimensional image, is the ordinate of the pixel point in the multi-spectral polarization two-dimensional image; is the wavelength corresponding to the multi-spectral polarization two-dimensional image, which is the design value of the detector module;

[0028] represents the multi-spectral image reconstruction algorithm based on multi-channel deconvolution, represents the inverse operation of the spatial matrix change, which is calculated from the change coefficients of the spectral channel magnification and rotation angle; is the imaging distance corresponding to the spectral channel and is the design value of the detector module; represents the multi-spectral polarization image, is the abscissa of the pixel point in the multi-spectral polarization image, is the ordinate of the pixel point in the multi-spectral polarization image; represents the point spread function of the detector module;

[0029] Step 5.2: Use the spatially-varying Richardson-Lucy algorithm to perform aberration correction on the four polarization channels of 0°, 45°, 90°, and 135° of each multi-spectral polarization two-dimensional image to obtain the aberration-corrected multi-spectral polarization two-dimensional image;

[0030] Step 5.3: According to the responsivity of the detector module, perform intensity correction on the four polarization channels of 0°, 45°, 90°, and 135° of each aberration-corrected multi-spectral polarization two-dimensional image through the following formula to obtain the intensity-corrected multi-spectral polarization two-dimensional image:

[0031]

[0032] where, represents the intensity-corrected multi-spectral polarization two-dimensional image, is the responsivity of the detector module;

[0033] Step 5.4: Use the MAXIM algorithm to remove weak noise interference from the four polarization channels of 0°, 45°, 90°, and 135° of the intensity-corrected multi-spectral polarization two-dimensional image respectively to obtain the corrected multi-spectral polarization two-dimensional image;

[0034] Step 5.5: Input the corrected multi-spectral polarization two-dimensional image into the 3D U-net neural network model for spectral reconstruction to obtain the three-dimensional multi-spectral image of each multi-spectral polarization image respectively, and obtain the polarization spectral data cube to complete the polarization spectral reconstruction.

[0035] Further, in Step 5.1, the specific method for obtaining the change coefficients of the magnification and rotation angle of different spectral channels in the multi-spectral polarization image is as follows:

[0036] Use the detector module to capture an image of the checkerboard calibration plate and perform preprocessing on it, extract the corner information of the checkerboard calibration plate and calculate the internal parameter matrix of the detector module, and then determine the change coefficients of the magnification and rotation angle of different spectral channels in the multi-spectral polarization image according to the internal parameter matrix of the detector module.

[0037] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0038] 1. The miniature high-energy-efficiency diffraction polarization spectral imaging device provided by the present invention adopts a macro imaging module, and can directly and compactly integrate a diffraction spectral lens module, an electrorheological lens module and a polarization module. It can not only reduce the spatial coupling distance of the traditional polarization spectral imaging device, but also effectively improve the imaging quality, meeting the development requirements of miniaturization and high quality of polarization spectral technology. In addition, the electrorheological lens module adopts an electro-controlled time-sharing regulation method, which can avoid the problem of low precision of traditional mechanical regulation. At the same time, its spatial size is much smaller than that of the traditional stepper motor regulation system, further reducing the size of the polarization spectral imaging device.

[0039] 2. The miniature high-energy-efficiency diffraction polarization spectral imaging device provided by the present invention realizes time-sharing spectral regulation of the diffraction spectral lens module through the electrorheological lens module, and the polarization module adopts a planar array spatial division polarization regulation, which can directly obtain the polarization information of 0°, 45°, 90° and 135° under different spectral channels, avoiding the absorption effect of the traditional filter on the spectrum, and the energy utilization rate is much higher than that of the traditional filter-type polarization spectral imaging device.

[0040] 3. The miniature high-energy-efficiency diffraction polarization spectral imaging device provided by the present invention uses a diffraction spectral lens module to diffract incident parallel light to form multiple multi-spectral images, and only needs to obtain the polarization information of 0°, 45°, 90° and 135° of the multi-spectral images. Compared with the traditional planar array polarization sensing technology that needs to obtain 16 kinds of polarization information, the number of polarization regions is greatly reduced, and at the same time, the spatial resolution of the detector is greatly improved, meeting the development trend of high-sensitivity and high-precision polarization spectral sensing technology.

[0041] 4. The miniature high-energy-efficiency diffraction polarization spectral imaging device provided by the present invention has N×N (2≤N≤16) macro imaging lenses arranged in a planar array. Correspondingly, N×N diffraction spectral lens elements, N×N electrorheological lenses and N×N polarization elements are all arranged in a planar array, making the overall imaging device adopt a planar array sensing method, with a high degree of freedom of regulation, and can realize high-degree-of-freedom intelligent sensing of various polarization spectral information, and then realize high-intelligence non-uniform heterogeneous integrated sensing of polarization spectral information, meeting the development trend of intelligence and multi-degree-of-freedom of polarization spectral technology.

[0042] 5. The polarization spectral reconstruction method provided by the present invention comprehensively uses a variety of image correction methods and a 3D U-net network structure, which can improve the sensing accuracy of polarization spectral information and realize high-precision reconstruction of polarization spectral information. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic structural diagram of the miniature high-energy-efficiency diffraction polarization spectral imaging device in the first embodiment of the present invention (the image processing module is not shown).

[0044] Figure 2Schematic diagram of the structure of the macro imaging module in the first embodiment of the present invention;

[0045] Figure 3 Schematic diagram of the structure of the diffraction spectrum lens module in the first embodiment of the present invention;

[0046] Figure 4 Schematic diagram of the structure of the electrically controlled rheological lens module in the first embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the structure of a miniature high-energy-efficiency diffraction polarization spectral imaging device according to Embodiment 2 of the present invention (the image processing module is not shown);

[0048] The following are the descriptions of the reference numerals:

[0049] 1-macro imaging module, 2-diffraction spectral lens module, 3-electro-controlled rheological lens module, 4-polarization module, 5-detector module, 6-macro imaging lens, 7-diffraction spectral lens element, 8-electro-controlled rheological lens, 9-polarization element, 10-detector. DETAILED DESCRIPTION

[0050] The miniature high energy efficiency diffraction polarization spectrum imaging device and polarization spectrum reconstruction method thereof proposed in the present invention are further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0051] Embodiment 1

[0052] A miniature high energy efficiency diffraction polarization spectral imaging device, such as Figure 1 As shown, it includes a macro imaging module 1, a diffraction spectrum lens module 2, an electro-rheological lens module 3, a polarization module 4 and a detector module 5 which are sequentially arranged along the transmission direction of the incident light beam, and an image processing module electrically connected to the detector module 5. The macro imaging module 1 couples the incident light beam to form incident parallel light and transmits it to the diffraction spectrum lens module 2; the diffraction spectrum lens module 2 diffracts the incident parallel light along its transmission direction to form a plurality of multi-spectral images respectively located at different spatial positions; the electro-rheological lens module 3 time-sharingly adjusts the focal lengths of the above-mentioned plurality of multi-spectral images so that they are sequentially located on the polarization module 4; the polarization module 4 realizes the surface array detection of 0 degree polarization information, 45 degree polarization information, 90 degree polarization information and 135 degree polarization information to obtain a plurality of multi-spectral polarization images; the detector module 5 detects the plurality of multi-spectral polarization images, and the image processing module reconstructs the polarization spectrum information according to the multi-spectral polarization images.

[0053] like Figure 2As shown, the macro imaging module 1 includes 2×2 macro imaging lenses 6 arranged in a planar array. The macro imaging lenses 6 are used to couple the incident light beam to form incident parallel light. The optical parameters such as the focal length and aperture of the macro imaging lenses 6 are determined by the sizes of the diffraction spectral lens module 2, the electro-rheological lens module 3, and the detector module 5 at the back end.

[0054] As Figure 3 shown, the diffraction spectral lens module 2 includes 2×2 diffraction spectral lens elements 7 corresponding to the 2×2 macro imaging lenses 6 respectively. The 2×2 diffraction spectral lens elements 7 are arranged in a black light-blocking planar array structure to achieve one-time planar array imaging of the diffraction spectrum. Each diffraction spectral lens element 7 is used to diffract the incident parallel light along its transmission direction to form 4 multi-spectral images located at different spatial positions respectively.

[0055] As Figure 4 shown, the electro-rheological lens module 3 includes 2×2 electro-rheological lenses 8 corresponding to the 2×2 diffraction spectral lens elements 7 respectively. The 2×2 electro-rheological lenses 8 are arranged in a black light-blocking planar array structure. The electro-rheological lens 8 uses an externally applied voltage time-division control method to control the focal lengths of the 4 multi-spectral images formed by the corresponding diffraction spectral lens elements 7, so that the 4 multi-spectral images are sequentially located on the polarization module 4. This externally applied voltage method can be freely designed to achieve non-uniform heterogeneous multi-spectral position focusing, and further achieve high-degree-of-freedom non-uniform heterogeneous polarization spectral information regulation. The externally applied voltage time-division control method can adopt sequential multi-spectral focusing position control, non-uniform heterogeneous multi-spectral focusing position control, etc.

[0056] As Figure 1 shown, the polarization module 4 includes 2×2 polarization elements 9 corresponding to the 2×2 electro-rheological lenses 8 respectively. Each polarization element 9 includes a 2×2 polarization combination area composed of 0-degree, 45-degree, 90-degree, and 135-degree polarization areas. The polarization module 4 uses a planar array spatial division polarization control method to achieve planar array detection of the 0-degree polarization information, 45-degree polarization information, 90-degree polarization information, and 135-degree polarization information of the 4 multi-spectral images, and a total of 2×2 sets of multi-spectral polarization image sets are obtained. Each set of multi-spectral polarization image sets includes 4 multi-spectral polarization images. In this embodiment, the 2×2 polarization elements 9 adopt a metal wire grid structure and are directly arranged on the detector module 5. The detector module 5 includes 2×2 detectors 10 corresponding to the polarization elements 9 respectively. Each detector 10 is used to detect and image the 4 multi-spectral polarization images and send them to the image processing module. The detection imaging period of the detector 10 is consistent with the focal length control period of the electro-rheological lens 8. The detector 10 is a planar array photoelectric conversion device and adopts a four-quadrant detector. In other embodiments, the detector module 5 can also directly adopt a planar array camera.

[0057] In this embodiment, the macro imaging module 1, the diffraction spectral lens module 2, the electro-rheological lens module 3, the polarization module 4, and the detector module 5 are all area array structures, which can realize the area array sensing of the spatial distribution characteristics of polarization spectral information. The diffraction spectral lens module 2 can obtain a variety of spectral information, and the polarization module 4 can obtain a variety of polarization information. When used in combination, they can not only increase the dimension of the information sensed by the imaging device, but also avoid the absorption of the spectrum by traditional filters, improve the energy utilization rate, and reduce the number of polarization regions, making the imaging device have a smaller volume. At the same time, through the electro-rheological lens 8, the multi-degree-of-freedom intelligent regulation of the focal length of the multi-spectral image can be realized, so as to realize the high-degree-of-freedom intelligent sensing of a variety of polarization spectral information, and further realize the highly intelligent non-uniform heterogeneous integrated sensing of polarization spectral information.

[0058] This embodiment also provides a polarization spectral reconstruction method for the above-mentioned micro high-efficiency diffraction polarization spectral imaging device, including the following steps:

[0059] Step 1: After the incident light beam passes through 2×2 macro imaging lenses 6, it is coupled to form 2×2 beams of incident parallel light and transmitted to 2×2 diffraction spectral lens elements 7 respectively.

[0060] Step 2: Each diffraction spectral lens element 7 diffracts a beam of incident parallel light into 4 multi-spectral images located at different spatial positions along its transmission direction, and transmits them to the corresponding electro-rheological lens 8.

[0061] Step 3: Each electro-rheological lens 8 respectively regulates the focal lengths of its corresponding 4 multi-spectral images by using the electro-control time-sharing regulation method, so that the 4 multi-spectral images are sequentially located at the corresponding polarization elements 9.

[0062] Step 4: Each polarization element 9 respectively regulates the polarization states of its corresponding 4 multi-spectral images to obtain the 0-degree polarization information, 45-degree polarization information, 90-degree polarization information, and 135-degree polarization information of the 4 multi-spectral images. Then, the detector module 5 detects and images them and sends them to the image processing module, and a total of 2×2 sets of multi-spectral polarization image sets are obtained. Each set of multi-spectral polarization image sets includes 4 multi-spectral polarization images, and each multi-spectral polarization image includes four polarization channels of 0 degree, 45 degrees, 90 degrees, and 135 degrees.

[0063] Step 5: The image processing module respectively performs spatial correction, aberration correction, intensity correction, and denoising on the multi-spectral polarization images in the 2×2 sets of multi-spectral polarization image sets detected by the detector module 5, and then inputs them into the 3D U-net neural network model for spectral reconstruction to obtain the polarization spectral data cube, and completes the polarization spectral reconstruction. Specifically:

[0064] Step 5.1: Use the detector module 5 to capture an image of the checkerboard calibration plate and preprocess it. Extract the corner information of the checkerboard calibration plate and calculate the internal parameter matrix of the detector module 5. Then, determine the change coefficients of the magnification and rotation angle in different spectral channels in the multi-spectral polarization image. Next, perform spatial correction on the four polarization channels of 0 degrees, 45 degrees, 90 degrees, and 135 degrees of each multi-spectral polarization image through the following formula to obtain a multi-spectral polarization two-dimensional image with a consistent spatial size:

[0065]

[0066] Among them, represents the multi-spectral polarization two-dimensional image, is the abscissa of the pixel point in the multi-spectral polarization two-dimensional image, is the ordinate of the pixel point in the multi-spectral polarization two-dimensional image; is the wavelength corresponding to the multi-spectral polarization two-dimensional image, which is the design value of the detector module 5;

[0067] represents the multi-spectral image reconstruction algorithm based on multi-channel deconvolution, represents the inverse operation of the spatial matrix change, which is calculated from the change coefficients of the spectral channel magnification and rotation angle; is the imaging distance corresponding to the spectral channel, which is the design value of the detector module 5; represents the multi-spectral polarization image, is the abscissa of the pixel point in the multi-spectral polarization image, is the ordinate of the pixel point in the multi-spectral polarization image; represents the point spread function of the detector module 5.

[0068] Step 5.2: Use the spatially-varying Richardson-Lucy algorithm to perform aberration correction on the four polarization channels of 0 degrees, 45 degrees, 90 degrees, and 135 degrees of each multi-spectral polarization two-dimensional image to obtain a multi-spectral polarization two-dimensional image after aberration correction.

[0069] Step 5.3: According to the responsivity of the detector module 5, perform intensity correction on the four polarization channels of 0 degrees, 45 degrees, 90 degrees, and 135 degrees of each multi-spectral polarization two-dimensional image after aberration correction through the following formula to obtain a multi-spectral polarization two-dimensional image after intensity correction:

[0070]

[0071] Among them, represents the multi-spectral polarization two-dimensional image after intensity correction, is the responsivity of the detector module 5.

[0072] Step 5.4: Use the MAXIM algorithm (Multi-Axis Multilayer Perceptron for Image Processing) to remove weak noise interference from the four polarization channels of 0°, 45°, 90°, and 135° of the intensity-corrected multi-spectral polarization two-dimensional image, respectively, to obtain the corrected multi-spectral polarization two-dimensional image;

[0073] Step 5.5: Input the corrected multi-spectral polarization two-dimensional image into the 3D U-net neural network model (Hybrid space calibrated 3D Network, spatial calibration diffraction spectral reconstruction algorithm, from Fan, H.; Li, C.; Gao, B.; Xu, H.; Chen, Y.; Zhang, X.; Li, X.; Yu, W. Hybrid Space Calibrated 3D Network of Diffractive Hyperspectral Optical Imaging Sensor. Sensors 2024, 24, 6903. https: / / doi.org / 10.3390 / s24216903) for spectral reconstruction to obtain the three-dimensional multi-spectral image of each multi-spectral polarization image, and obtain the polarization spectral data cube to complete the polarization spectral reconstruction. In this step, the specific method of using the 3D U-net neural network model to perform spectral reconstruction on the corrected multi-spectral polarization two-dimensional image is as follows:

[0074] Configure the maximum number of training times, regularization coefficient, and loss allocation coefficient of the 3D U-net neural network model, select the training set to iteratively optimize the structural parameters of the 3D U-net neural network model, and then input the corrected multi-spectral polarization two-dimensional image into the 3D U-net neural network model for spectral reconstruction. Among them, during the iterative optimization process, the SSIM (Structural Similarity Index Measure) and PSNR (Peak Signal-to-Noise Ratio) are used to measure the accuracy of spectral reconstruction.

[0075] In Step 5, first unify the spatial size through spatial calibration, then avoid the aberration caused by the electro-rheological lens module 3 through aberration correction, unify the intensity through intensity correction, and improve the signal-to-noise ratio by removing weak noise interference, which can improve the image quality and thus improve the accuracy of spectral reconstruction.

[0076] Embodiment 2

[0077] The overall structure, detection principle, and polarization spectrum reconstruction method of this embodiment are the same as those of Embodiment 1. As Figure 5 shown, the difference is that the macro imaging module 1 includes a single macro imaging lens 6 to meet the application requirements of lightweight, small-sized, and low-cost polarization spectrum detection imaging. Correspondingly, the diffraction spectrum lens module 2 includes a diffraction spectrum lens element 7, the electro-rheological lens module 3 includes an electro-rheological lens 8, the polarization module 4 includes a polarization element 9, and the detector module 5 includes a detector 10, which can realize the detection imaging of multi-spectral polarization images.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present invention.

Claims

1. A micro high-efficiency diffraction polarization spectroscopic imaging device, characterized in that: It includes a macro imaging module (1), a diffraction spectral lens module (2), an electro-rheological lens module (3), a polarization module (4), and a detector module (5) arranged in sequence along the transmission direction of the incident light beam, as well as an image processing module electrically connected to the detector module (5); The macro imaging module (1) includes N×N macro imaging lenses (6) arranged in a matrix, which are used to couple the incident light beam to form N×N beams of incident parallel light. N is an integer, and 2≤N≤16; The diffraction spectral lens module (2) includes N×N diffraction spectral lens elements (7) respectively corresponding to the N×N macro imaging lenses (6). Each diffraction spectral lens element (7) is used to diffract the corresponding incident parallel light along its transmission direction to form M multi-spectral images located at different spatial positions respectively, where M = N×N; The electro-rheological lens module (3) includes N×N electro-rheological lenses (8) respectively corresponding to the N×N diffraction spectral lens elements (7). The electro-rheological lens (8) uses an electrically controlled time-sharing regulation method to regulate the focal lengths of the M multi-spectral images formed by the corresponding diffraction spectral lens elements (7), so that the M multi-spectral images are sequentially located on the polarization module (4); The polarization module (4) includes N×N polarization elements (9) respectively corresponding to the N×N electro-rheological lenses (8); each polarization element (9) includes a 2×2 polarization combination area composed of polarization areas of 0°, 45°, 90°, and 135°. The polarization module (4) uses a matrix spatial division polarization regulation method to respectively realize the matrix detection of the 0° polarization information, 45° polarization information, 90° polarization information, and 135° polarization information of the M multi-spectral images, and a total of N×N sets of multi-spectral polarization image sets are obtained. Each set of multi-spectral polarization image sets includes M multi-spectral polarization images; The detector module (5) is used to detect and image the N×N sets of multi-spectral polarization image sets and send them to the image processing module. The detection imaging period of the detector module (5) is consistent with the electrically controlled time-sharing regulation period of the electro-rheological lens (8).

2. The micro high-efficiency diffraction polarization spectroscopic imaging device according to claim 1, wherein: The detector module (5) includes N×N detectors (10) respectively corresponding to the N×N polarization elements (9). Each detector (10) is used to realize the detection imaging of the M multi-spectral polarization images obtained by the corresponding polarization element (9).

3. The micro high-efficiency diffractive polarization spectral imaging device according to claim 2, wherein: The detector (10) is a four-quadrant detector.

4. The micro high-efficiency diffraction polarization spectral imaging device according to claim 1, wherein: The detector module (5) is a matrix camera.

5. The micro high-efficiency diffraction polarization spectral imaging device according to any one of claims 1-4, characterized in that: The electro-rheological lens (8) uses an externally applied voltage time-sharing regulation method to regulate the focal length.

6. The micro high-efficiency diffractive polarization spectroscopic imaging device according to claim 5, wherein: The N×N diffraction spectral lens elements (7) are arranged in a black light-blocking matrix structure; the N×N electro-rheological lenses (8) are arranged in a black light-blocking matrix structure; the N×N polarization elements (9) adopt a metal wire grid structure and are directly arranged on the detector module (5).

7. A polarization spectrum reconstruction method for a micro high-efficiency diffraction polarization spectrum imaging device according to any one of claims 1-6, characterized in that, It includes the following steps: Step 1: After the incident light beam passes through the N×N macro imaging lenses (6), it is coupled to form N×N beams of incident parallel light and is respectively transmitted to the N×N diffraction spectral lens elements (7); Step 2: Each diffractive spectral lens element (7) diffracts a beam of incident parallel light into M multi-spectral images located at different spatial positions along its transmission direction and transmits them to the corresponding electro-rheological lens (8). Step 3: Each electro-rheological lens (8) uses an electro-controlled time-division regulation method to regulate the focal lengths of its corresponding M multi-spectral images respectively, so that the M multi-spectral images are sequentially located on the corresponding polarization elements (9). Step 4: Each polarization element (9) uses a planar array spatial division polarization regulation method to regulate the polarization states of its corresponding M multi-spectral images respectively, obtaining 0-degree polarization information, 45-degree polarization information, 90-degree polarization information, and 135-degree polarization information of the M multi-spectral images. Then, the detector module (5) detects and images them and sends them to the image processing module, obtaining a total of N×N sets of multi-spectral polarization image sets; each set of multi-spectral polarization image sets includes M multi-spectral polarization images, and each multi-spectral polarization image includes four polarization channels of 0 degrees, 45 degrees, 90 degrees, and 135 degrees. Step 5: The image processing module sequentially performs spatial correction, aberration correction, intensity correction, and denoising on the multi-spectral polarization images in the N×N sets of multi-spectral polarization image sets detected by the detector module (5), and then inputs them into a 3D U-net neural network model for spectral reconstruction to obtain a polarization spectral data cube, completing the polarization spectral reconstruction.

8. The polarization spectrum reconstruction method of the micro high-efficiency diffraction polarization spectrum imaging device according to claim 7, characterized in that, Step 5 is specifically as follows: Step 5.1: Obtain the variation coefficients of the magnification and rotation angle of different spectral channels in the multi-spectral polarization image, and then perform spatial correction on the 0-degree, 45-degree, 90-degree, and 135-degree four polarization channels of each multi-spectral polarization image respectively through the following formula to obtain a multi-spectral polarization two-dimensional image with a consistent spatial size: I(ξ,ζ,λ) = Deconv(K -1 (λ,z)*O(m,n,λ),H(m - ξ,n - ζ,λ)) where I(ξ,ζ,λ) represents the multi-spectral polarization two-dimensional image, ξ is the abscissa of the pixel point in the multi-spectral polarization two-dimensional image, ζ is the ordinate of the pixel point in the multi-spectral polarization two-dimensional image; λ is the wavelength corresponding to the multi-spectral polarization two-dimensional image, which is the design value of the detector module (5). Deconv() represents a multi-spectral image reconstruction algorithm based on multi-channel deconvolution, and K -1 () represents the inverse operation of the spatial matrix change, which is calculated from the spectral channel magnification and the change coefficient of the rotation angle; z is the imaging distance corresponding to the spectral channel and is the design value of the detector module (5); O(m, n, λ) represents the multi-spectral polarization image, where m is the abscissa of the pixel point in the multi-spectral polarization image, and n is the ordinate of the pixel point in the multi-spectral polarization image; H() represents the point spread function of the detector module (5); Step 5.2: Use the spatially-varying Richardson-Lucy algorithm to perform aberration correction on the 0-degree, 45-degree, 90-degree, and 135-degree four polarization channels of each multi-spectral polarization two-dimensional image to obtain an aberration-corrected multi-spectral polarization two-dimensional image. Step 5.3: According to the responsivity of the detector module (5), perform intensity correction on the 0-degree, 45-degree, 90-degree, and 135-degree four polarization channels of each aberration-corrected multi-spectral polarization two-dimensional image through the following formula to obtain an intensity-corrected multi-spectral polarization two-dimensional image: I(λ)=Deconv(O(m,n,λ),H(m-ξ,n-ζ,λ)) / P where I(λ) represents the intensity-corrected multi-spectral polarization two-dimensional image, and P is the responsivity of the detector module (5). Step 5.4: Use the MAXIM algorithm to remove weak noise interference from the 0-degree, 45-degree, 90-degree, and 135-degree four polarization channels of each intensity-corrected multi-spectral polarization two-dimensional image respectively to obtain a corrected multi-spectral polarization two-dimensional image. Step 5.5: Input the corrected multi-spectral polarization two-dimensional image into the 3D U-net neural network model for spectral reconstruction to obtain the three-dimensional multi-spectral image of each multi-spectral polarization image, that is, obtain the polarization spectral data cube, and complete the polarization spectral reconstruction.

9. The polarization spectrum reconstruction method of the micro high-efficiency diffraction polarization spectrum imaging device according to claim 8, characterized in that In step 5.1, the specific method for obtaining the variation coefficients of the magnification and rotation angle of different spectral channels in the multi-spectral polarization image is as follows: Use the detector module (5) to capture the image of the checkerboard calibration plate and preprocess it, extract the corner information of the checkerboard calibration plate and calculate the internal parameter matrix of the detector module (5), and then determine the variation coefficients of the magnification and rotation angle of different spectral channels in the multi-spectral polarization image according to the internal parameter matrix of the detector module (5).

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