Spectroscopic polarization multi-modal composite imaging system and method

Abstract

The present application relates to a kind of spectral polarization multi-mode composite imaging system and method, by setting digital micro-mirror chip, dispersive element, spectral-polarization regulator, photoelectric detector and control device, digital micro-mirror chip includes the micro-mirror matrix formed by multiple micro-mirror, every micro-mirror in micro-mirror matrix has two states of light transmission and light shielding, the state of each micro-mirror is individually controlled by control device, a wideband filter device, several narrowband filter devices and several linear polarization filter devices are arranged in annular distribution on the turntable of spectral-polarization regulator, under the combination of digital micro-mirror chip, dispersive element, spectral-polarization regulator and control device, the spectral polarization imaging of multiple channels can be realized, satisfy in spectral polarization imaging technology three major resolution can be simultaneously achieved The technical requirements of best.

Description

Technical Field

[0001] This invention relates to the field of optical system technology, and more specifically, to a spectral polarization multimode composite imaging system and method. Background Technology

[0002] Spectral imaging of a target can obtain its two-dimensional spatial information and one-dimensional spectral information, while polarization imaging of a target can obtain its two-dimensional spatial information and multi-dimensional polarization information. Spectral polarization imaging technology, which combines spectral imaging and polarization imaging, can simultaneously obtain the target's two-dimensional spatial information, one-dimensional spectral information, and multi-dimensional polarization information, thereby providing a comprehensive understanding of the target's spectral characteristics.

[0003] Existing technology discloses a spectral polarization imaging technique that integrates staring spectral imaging with time-division polarization imaging. This technique utilizes a combination of a liquid crystal tunable filter (LCTF) and a liquid crystal tunable phase retarder (LCVR) to achieve spectral polarization imaging. Due to the inherent characteristics of staring spectral imaging, this technique can achieve high spatial resolution, but its spectral and temporal resolutions do not meet expectations.

[0004] Meanwhile, existing technologies combine coded aperture snapshot spectral imaging with time-division polarization imaging using digital micromirror devices (DMDs) to form coded aperture snapshot spectral polarization imaging. This technology uses a rotatable quarter-wave plate (QWP) and a rotatable polarizer as polarization modulation components to modulate polarization information in the spectrum. Aperture encoding is then achieved using a DMD, followed by modulation by a dispersive element. The resulting coded polarization-modulated spectral image is recorded by a camera. A sparse constraint optimization method is used to estimate the polarization-modulated spectral image, and a demodulation algorithm is used to calculate a spectral polarization image with full Stokes properties. While this technology, with the aid of a DMD, can achieve high temporal resolution, its spectral and spatial resolutions do not meet expectations.

[0005] Furthermore, existing technology discloses a compressed spatial dimension dual-coded hyperspectral polarization imaging system. This system combines coded aperture snapshot spectral imaging technology with focal plane polarization imaging technology. It uses a micropolarizer array detector (MPA) as a polarization modulation module, directly performing polarization modulation on the detector surface. It employs digital micromirror devices for spatial encoding and a prism-grating-prism (PGP) to modulate the spectral information. Finally, the spectral polarization information of the target can be obtained in a single exposure. While this system achieves high temporal resolution through the combination of digital micromirror devices and the prism-grating-prism, its spectral and spatial resolutions do not meet expectations.

[0006] Therefore, the spectral polarization imaging techniques listed above all have contradictions between temporal resolution, spatial resolution, and spectral resolution (hereinafter referred to as the three resolutions). Specifically, the three resolutions restrict each other and it is difficult to achieve the best at the same time. Summary of the Invention

[0007] The technical problem to be solved by this invention is how to achieve the best technical effect of simultaneous three resolutions in spectral polarization imaging technology. To solve the above technical problem, this invention provides a spectral polarization multi-mode composite imaging system and method, specifically including a spectral polarization multi-mode composite imaging system, a spectral polarization multi-mode composite imaging method, a pushbroom spectral imaging method, a staring spectral imaging method, a transform spectral imaging method, a snapshot spectral imaging method, a pushbroom spectral polarization imaging method, a transform spectral polarization imaging method, and a snapshot spectral polarization imaging method.

[0008] This invention provides a spectral polarization multi-mode composite imaging system, comprising a control device and components arranged sequentially along the signal light propagation direction of the target imaging scene:

[0009] The digital micromirror chip contains a micromirror matrix composed of multiple micromirrors, and each micromirror has two states: light transmission and light blocking. The state of each micromirror is controlled individually.

[0010] Dispersive element;

[0011] A spectral polarization modulator consists of a motor and a turntable mounted on the output shaft of the motor. Multiple filter elements are arranged in a ring on the turntable. The multiple filter elements consist of a broadband filter element, several narrowband filter elements, and several linear polarization filter elements. The motor is used to drive the turntable to rotate so that one of the filter elements is located in the propagation path of the signal light.

[0012] Photodetector;

[0013] The control device is electrically connected to both the digital micromirror chip and the motor to control the state of each micromirror and the rotation angle of the motor's output shaft, respectively.

[0014] The spectral polarization multimode composite imaging system disclosed in this invention comprises a digital micromirror chip, a dispersive element, a spectral polarization modulator, and a photodetector arranged sequentially along the signal light propagation direction of the target imaging scene. The digital micromirror chip includes a micromirror matrix composed of multiple micromirrors, each of which has two states: light-transmitting and light-blocking. The state of each micromirror is individually controlled. Because the digital micromirror chip, dispersive element, and spectral polarization modulator are arranged sequentially along the signal light propagation direction of the target imaging scene, when a micromirror in the micromirror matrix is ​​in the light-transmitting state, the signal light received by this micromirror can be introduced into the dispersive element; conversely, it will not be introduced. The signal light introduced into the dispersive element is dispersed to form dispersed light. Since the spectral polarization modulator's turntable has a wideband filter, several narrowband filters, and several linear polarization filters arranged in a ring, under the action of the spectral polarization modulator's motor, one of the filters can be positioned on the signal light propagation path. Therefore, by combining digital micromirror chip, dispersive element and spectral-polarization modulator, multi-channel spectral polarization imaging can be realized, and the imaging information can be received by photodetector, ultimately realizing the acquisition of the target's spectral and polarization information.

[0015] Meanwhile, the spectral polarization multi-mode composite imaging system disclosed in this invention also includes a control device to control the state of each micromirror and the rotation angle of the motor's output shaft. Therefore, based on acquiring the target's spectral and polarization information, it can also achieve pushbroom, staring, transformation, and snapshot spectral imaging. Furthermore, due to the linear polarization filter device, pushbroom, transformation, and snapshot spectral imaging can be combined with polarization imaging for spectral polarization imaging, achieving a total of seven different imaging modes. Under this multi-mode spectral polarization imaging, different spectral polarization imaging modes can be selected for different target scenes to specifically adjust the three resolutions, ultimately achieving highly flexible, multi-scene adaptable adaptive spectral polarization imaging, meeting the technical requirement of simultaneously achieving optimal resolution across the three resolutions in spectral polarization imaging technology.

[0016] In one possible implementation, the composite imaging system further includes an imaging lens, a collimating lens, and a converging lens. The imaging lens, the digital micromirror chip, the collimating lens, the dispersive element, the converging lens, the spectral-polarization adjuster, and the photodetector are arranged sequentially along the direction of signal light propagation. The imaging lens clearly projects the image of the target scene onto the surface of the digital micromirror chip. The collimating lens collimates the light reflected from the digital micromirror chip, allowing its principal ray to be incident parallel to the surface of the dispersive element. The converging lens converges the dispersed light beam to improve the photodetector's efficiency in receiving imaging information.

[0017] The present invention provides a spectral polarization multi-mode composite imaging method, comprising the following steps:

[0018] Users can choose one of the following seven modes: pushbroom spectral imaging, staring spectral imaging, transform spectral imaging, snapshot spectral imaging, pushbroom spectral polarization imaging, transform spectral polarization imaging, and snapshot spectral polarization imaging.

[0019] If pushbroom spectral imaging is selected, the pushbroom spectral imaging method is executed to obtain imaging results;

[0020] If staring spectral imaging is selected, the staring spectral imaging method will be executed to obtain the imaging results;

[0021] If transform spectral imaging is selected, the transform spectral imaging method will be executed to obtain the imaging results;

[0022] If snapshot spectral imaging is selected, the snapshot spectral imaging method will be executed to obtain the imaging results;

[0023] If pushbroom spectral polarization imaging is selected, the pushbroom spectral polarization imaging method will be executed to obtain the imaging results;

[0024] If transform-type spectral polarization imaging is selected, the transform-type spectral polarization imaging method will be executed to obtain the imaging results;

[0025] If snapshot spectral polarization imaging is selected, the snapshot spectral polarization imaging method will be executed to obtain the imaging results.

[0026] The spectral polarization multi-mode composite imaging method disclosed in this invention first allows the user to select one of seven modes from different target scenarios: pushbroom spectral imaging, staring spectral imaging, transform spectral imaging, snapshot spectral imaging, pushbroom spectral polarization imaging, transform spectral polarization imaging, and snapshot spectral polarization imaging. Different methods are used for different modes to adjust the three resolutions in a targeted manner, ultimately achieving highly flexible and multi-scenario adaptable adaptive spectral polarization imaging, which meets the technical requirement of achieving the best simultaneous resolution of the three modes in spectral polarization imaging technology.

[0027] The present invention provides a pushbroom spectral imaging method, comprising the following steps:

[0028] S11: Adjust the rotation angle of the motor's output shaft using the control device so that the broadband filter device is positioned on the propagation path of the signal light in the target imaging scene;

[0029] S12: Select multiple micromirror columns of the digital micromirror chip and divide the multiple micromirror columns into several column units;

[0030] S13: The control device is used to control the light transmission of each column unit separately, and the photodetector is used to obtain the dispersive spectrum image corresponding to the light transmission of each column unit;

[0031] S14: Store all the dispersive spectral images obtained in step S13 in BIL format, and then convert the BIL format into BSQ format by extracting the spectral information of the spatial location to represent the spatial distribution of the target imaging scene in different bands and obtain the imaging result.

[0032] The pushbroom spectral imaging method described above stores the acquired dispersive spectral image in BIL format, and then converts it into BSQ format by extracting the spectral information of the spatial location, so that the pushbroom spectral imaging information can represent the spatial distribution of the target imaging scene in different bands in detail.

[0033] The present invention provides a staring spectral imaging method, comprising the following steps:

[0034] S21: Select multiple micromirror columns of the digital micromirror chip, divide the multiple micromirror columns into several column units, and then control all column units to transmit light through the control device.

[0035] S22: Adjust the rotation angle of the output shaft of the motor through the control device to position each narrowband filter device on the propagation path of the signal light, and obtain the corresponding dispersive spectral image through the photodetector when each narrowband filter device is on the propagation path of the signal light.

[0036] S23: Convert all the dispersive spectral images obtained in step S22 into BSQ format to obtain imaging results.

[0037] The above-described staring spectral imaging method achieves staring spectral imaging by manipulating the rotation angle of the digital micromirror chip and the output shaft of the motor, which improves imaging efficiency and imaging quality at the same time.

[0038] The present invention provides a transform-type spectral imaging method, comprising the following steps:

[0039] S31: Adjust the rotation angle of the motor's output shaft using the control device so that the broadband filter device is positioned on the propagation path of the signal light in the target imaging scene;

[0040] S32: Select multiple micromirror columns of the digital micromirror chip and divide the multiple micromirror columns into several column units;

[0041] S33: Set a non-singular matrix in the binary domain with an order equal to the number of column units obtained in step S32. Let the value of all elements in the j-th column of the i-th transformation matrix be equal to the value of the element in the i-th row and j-th column of the non-singular matrix, so as to generate a transformation matrix with a number equal to the number of column units obtained in step S32.

[0042] S34: The state of all micromirrors in the column unit obtained in step S32 is controlled by the control device according to each of the transformation matrices, and the dispersive spectral image corresponding to each of the transformation matrices is obtained by the photodetector;

[0043] S35: Use the format conversion formula to convert all the dispersive spectral images obtained in step S34 into BIL format spectral data cubes to obtain imaging results.

[0044] The above-described transform-based spectral imaging method first places the broadband filter device on the propagation path of the signal light in the target imaging scene, and then generates a transformation matrix using a non-singular matrix constructed on a binary domain to control the state of the micromirror and achieve the adjustment of spectral and spatial resolution.

[0045] The present invention provides a snapshot-type spectral imaging method, comprising the following steps:

[0046] S41: Adjust the rotation angle of the motor's output shaft using the control device so that the broadband filter device is positioned on the propagation path of the signal light in the target imaging scene;

[0047] S42: Select multiple rows and columns of micromirrors from the digital micromirror chip to obtain the working area;

[0048] S43: Construct an encoding matrix on the binary domain that is adapted to the working area selected in step S42 and satisfies the constraint equidistant condition, and control the state of all micromirrors in the working area according to the encoding matrix through the control device;

[0049] S44: Obtain a dispersive spectral image using a photodetector;

[0050] S45: Determine whether the number of currently acquired dispersive spectral images is equal to the specified value.

[0051] If so, proceed to the next step;

[0052] If not, then return to step S43;

[0053] S46: Using all the dispersive spectral images currently available, model the spectral data cube reconstruction method as a least squares estimation problem with a regularization term;

[0054] S47: Solve the least squares estimation problem to obtain the distribution of spectral data cube estimates, and use the distribution of spectral data cube estimates as the imaging result.

[0055] The above-described snapshot-based spectral imaging method models the spectral data cube reconstruction method as a least squares estimation problem with a regularization term. By solving the least squares estimation problem, the distribution of spectral data cube estimates is obtained, which not only improves the efficiency of imaging but also enables controllable accuracy and temporal and spatial resolution.

[0056] The present invention provides a pushbroom-type spectral polarization imaging method, comprising the following steps:

[0057] S51: Adjust the rotation angle of the motor's output shaft using the control device so that one of the linear polarization filter devices is located on the propagation path of the signal light in the target imaging scene;

[0058] S52: Select multiple micromirror columns of the digital micromirror chip and divide the multiple micromirror columns into several column units;

[0059] S53: Control the light transmission of each column unit through the control device, and obtain the dispersive spectrum image corresponding to the light transmission of each column unit through the photodetector;

[0060] S54: Store all the dispersive spectral images obtained in step S53 in BIL format, and then convert the BIL format into BSQ format by extracting the spectral information of the spatial location to represent the spatial distribution of the target imaging scene in different bands.

[0061] S55: Determine whether all linear polarization filter devices on the turntable have been traversed.

[0062] If so, proceed to the next step;

[0063] If not, the rotation angle of the motor's output shaft is adjusted by the control device so that the next linear polarization filter is located on the propagation path of the signal light in the target imaging scene, and then the step S52 is executed in reverse.

[0064] S56: Cluster all the currently acquired BSQ format dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain the imaging results.

[0065] The pushbroom spectral polarization imaging method described above achieves pushbroom spectral polarization imaging by manipulating the rotation angle of the digital micromirror chip and the output shaft of the motor. By manipulating the digital micromirror chip multiple times, the temporal and spectral resolution of the obtained imaging results can be controlled.

[0066] This invention provides a transformation-based spectral polarization imaging method, which includes the following steps:

[0067] S61: Adjust the rotation angle of the output shaft of the motor through the control device so that one of the linear polarization filter devices is located on the propagation path of the signal light of the target imaging scene;

[0068] S62: Select multiple micromirror columns of the digital micromirror chip and divide the multiple micromirror columns into several column units;

[0069] S63: Set a non-singular matrix in the binary field with an order equal to the number of column units obtained in step S62, and let the value of all elements in the j-th column of the i-th transformation matrix be equal to the value of the element in the i-th row and j-th column of the non-singular matrix, so as to generate a transformation matrix with a number equal to the number of column units obtained in step S62.

[0070] S64: The state of all micromirrors in the column unit obtained in step S62 is controlled by the control device according to each of the transformation matrices, and the dispersive spectral image corresponding to each of the transformation matrices is obtained by the photodetector;

[0071] S65: Determine whether all linear polarization filter devices on the turntable have been traversed.

[0072] If so, proceed to the next step;

[0073] If not, the rotation angle of the motor's output shaft is adjusted by the control device so that the next linear polarization filter is located on the propagation path of the signal light in the target imaging scene, and then the step S62 is executed in reverse.

[0074] S66: Cluster all currently acquired dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain imaging results.

[0075] The aforementioned transform-type spectral polarization imaging method sequentially adjusts each linear polarization filter to the propagation path of the signal light in the target imaging scene. In each adjustment, multiple micromirror columns of the digital micromirror chip are selected, and these micromirrors are manipulated according to the set transformation matrix to complete transform-type spectral polarization imaging. This achieves controllable spectral and temporal resolution while improving imaging efficiency and quality.

[0076] The present invention provides a snapshot-type spectral polarization imaging method, comprising the following steps:

[0077] S71: Adjust the rotation angle of the motor's output shaft using the control device so that one of the linear polarization filter devices is located on the propagation path of the signal light in the target imaging scene;

[0078] S72: Select multiple rows and columns of micromirrors from the digital micromirror chip to obtain the working area;

[0079] S73: Construct an encoding matrix on the binary domain that is adapted to the working area selected in step S72 and satisfies the constraint equidistant condition, and use the control device to control the state of all micromirrors in the working area according to the encoding matrix;

[0080] S74: Obtain dispersive spectral images using a photodetector;

[0081] S75: Determine whether all linear polarization filter devices on the turntable have been traversed.

[0082] If so, proceed to the next step;

[0083] If not, the rotation angle of the motor's output shaft is adjusted by the control device so that the next linear polarization filter is located on the propagation path of the signal light in the target imaging scene, and then the step S72 is executed in reverse.

[0084] S76: Cluster all currently acquired dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain imaging results.

[0085] The aforementioned snapshot-type spectral polarization imaging method sequentially adjusts each linear polarization filter to the propagation path of the signal light in the target imaging scene. In each adjustment, the working area of ​​the digital micromirror chip is selected and an encoding matrix is ​​set. The state of all micromirrors in the working area is controlled according to the encoding matrix set each time, thus completing snapshot-type spectral polarization imaging. This improves imaging quality and efficiency while achieving controllable spectral resolution, temporal resolution, and spatial resolution. Attached Figure Description

[0086] Figure 1 This is a schematic diagram of the optical path structure of a spectral polarization multimode composite imaging system disclosed in an embodiment of the present invention;

[0087] Figure 2 This is a schematic diagram of the spectral-polarization modulator structure disclosed in the embodiments of the present invention;

[0088] Figure 3 This is a schematic diagram of a square-arranged digital micromirror chip disclosed in an embodiment of the present invention.

[0089] Figure 4 This is a schematic diagram showing the working area and the division of row and column reflection units of the diamond-shaped digital micromirror chip disclosed in the embodiments of the present invention.

[0090] Figure 5This is a schematic diagram showing the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during pushbroom spectral imaging as disclosed in the embodiments of the present invention.

[0091] Figure 6 This is a schematic diagram showing the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during the staring spectral imaging operation disclosed in the embodiments of the present invention.

[0092] Figure 7 This is a schematic diagram showing the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during the transformation spectral imaging operation disclosed in the embodiments of the present invention.

[0093] Figure 8 This is a schematic diagram showing the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during snapshot spectral imaging as disclosed in the embodiments of the present invention.

[0094] Figure 9 This is a schematic diagram showing the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during pushbroom spectral polarization imaging as disclosed in the embodiments of the present invention.

[0095] Figure 10 This is a schematic diagram showing the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during the operation of the transform spectral polarization imaging disclosed in the embodiments of the present invention.

[0096] Figure 11 This is a schematic diagram illustrating the modulation mode of the digital micromirror chip, the gating channel of the spectral-polarization modulator, and the data format obtained by the photodetector during snapshot-type spectral polarization imaging as disclosed in the embodiments of the present invention.

[0097] Explanation of reference numerals in the attached figures:

[0098] 1. Target imaging scene, 2. Imaging lens, 3. Digital micromirror chip, 4. Collimating lens, 5. Dispersion element, 6. Converging lens, 7. Spectral-polarization adjuster, 7-1. Motor, 7-2. Turntable, 8. Photodetector, 9. Control device. Detailed Implementation

[0099] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0100] In the embodiments of this application, unless otherwise explicitly specified and limited, the electrical connection between the first feature and the second feature means that there is a transmission of electrical signals between the first feature and the second feature. This transmission of electrical signals can be unidirectional or bidirectional, and the way to achieve the electrical connection can be through wire connection, radio connection, electromagnetic medium (such as semiconductor) connection, communication realized by channel, etc.

[0101] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0102] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0103] See Figure 1 , Figure 2 , Figure 3 and Figure 4 This application discloses a spectral polarization multimode composite imaging system. Figure 1 This is a schematic diagram of the optical path structure of the composite imaging system. The system includes a control device 9 and, sequentially arranged along the propagation direction of the signal light emitted or reflected from the target imaging scene 1, an imaging lens 2, a digital micromirror chip 3, a collimating lens 4, a dispersive element 5, a converging lens 6, a spectral-polarization adjuster 7, and a photodetector 8. The axes of the imaging lens 2, digital micromirror chip 3, collimating lens 4, dispersive element 5, and converging lens 6 are all located on the same horizontal plane. In this embodiment, a biological cell is selected as the target imaging scene 1.

[0104] In this composite imaging system, the imaging lens 2 is used to clearly image the target imaging scene 1 onto the surface of the digital micromirror chip 3. The imaging lens 2 is custom-designed and manufactured independently.

[0105] In this composite imaging system, the digital micromirror chip 3 contains a micromirror matrix composed of multiple micromirrors, and each micromirror has two states: light transmission and light blocking. The state of each micromirror is controlled individually.

[0106] Digital micromirror chip 3 is a digital micromirror chip device, see [link / reference] Figure 3 and Figure 4, which has N×M (N rows, M columns) micromirrors. Each micromirror has two states: transmitting light and blocking light, and the state of each micromirror can be controlled independently to achieve the function of an optical switch. There are mainly two different arrangements of the micromirrors on the digital micromirror chip 3. One is a square arrangement. Refer to Figure 3 , Figure 3 . The (left) in Figure 3 is a schematic diagram of a digital micromirror chip with a square arrangement. The (middle) in Figure 3 is a schematic diagram of a rectangular arrangement after rotating 45°. The (right) in Figure 4 is a diagram showing the reflection of light by the micromirrors. The other is a diamond arrangement. Refer to Figure 3 . The side length of each micromirror can be denoted as d, and the range of the deflection angle can be denoted as ±θ. When using the digital micromirror chip 3 with a square arrangement, this digital micromirror chip 3 needs to be rotated 45° around the main axis (vertically upward from the surface of the micromirror) to ensure that the incident light perpendicular to the surface of the micromirror and the signal light are on the same horizontal plane. Specifically, refer to the (right) in

[0107] . The square arrangement after rotating 45° is equivalent to the diamond arrangement.

[0107] Each micromirror in the digital micromirror chip 3 can be deflected positively and negatively. When the deflection angle of a certain micromirror is equal to θ, it is positively deflected, and at this time, this micromirror can introduce the signal light into the collimating lens 4, that is, this micromirror is in the light-transmitting state. When the deflection angle of a certain micromirror is equal to -θ, it is negatively deflected, and at this time, this micromirror cannot introduce the signal light into the collimating lens 4, that is, this micromirror is in the light-blocking state. In this embodiment, the digital micromirror chip 3 selects a micromirror chip with the model DLP7000, which has a square arrangement. The relevant parameters are: d = 13.68 μm, θ = 12°, N×M = 1027×768.Refer to Figure 3 . In this embodiment, m1 = 6 column reflection units and n1 = 4 row reflection units are selected as the working area. Each column reflection unit contains m0 = 3 micromirror columns, and each row reflection unit contains n0 = 3 micromirror rows. The side length of each (row or column) reflection unit is s is a positive real number. Denote the 6 column reflection units as c1,..., c m ,..., c6, and the 4 row reflection units as r1,..., r n ,..., r4. Therefore, there are a total of 6×4 reflection units, and the central position of each reflection unit is represented by (n, m).

[0108] In this compound imaging system, the collimating lens 4 is used to collimate the light reflected from the digital micromirror chip 3 so that its principal ray is incident parallel to the surface of the dispersion element 5.

[0109] In this composite imaging system, the dispersive element 5 is used to disperse and split the light beam incident on its surface, forming dispersed light. A dispersive prism, grating, or prism-grating-prism (PGP) can be used, exhibiting linear dispersion characteristics. The center wavelength of the dispersive element 5 is denoted as λ. c The linear dispersion is denoted as α. In this embodiment, a transmission blazed grating with a grating line count of 300 l / mm, a blaze wavelength of 550nm, and an operating wavelength range of 400-800nm ​​is selected as the dispersive element 5.

[0110] In this composite imaging system, the converging lens 6 is used to converge the dispersive light output from the dispersive element 5 so as to focus the dispersive light onto the surface of the spectral-polarization modulator 7.

[0111] See Figure 2 In this composite imaging system, the spectral-polarization modulator 7 consists of a motor 7-1 and a turntable 7-2 mounted on the output shaft of the motor 7-1. Multiple filter elements are arranged in a ring on the turntable 7-2. The multiple filter elements consist of a broadband filter element, several narrowband filter elements, and several linear polarization filter elements. The motor 7-1 is used to drive the turntable 7-2 to rotate so that one of the filter elements is located on the propagation path of the signal light of the target imaging scene 1.

[0112] The spectral-polarization adjuster 7 is a wheel-type rotating mechanism driven by a motor 7-1 to control the rotation of a turntable 7-2. O optical channels are distributed circumferentially on the turntable 7-2. These O optical channels include one broadband filter channel, P spectral channels, and Q polarization channels. The broadband filter channel is used to install a broadband filter device, and the filtering range of the installed broadband filter device is denoted as (λ). l ,λ h The P spectral channels are denoted as 1,...,P′,...,P, and are used to install narrowband filtering devices. The filtering range of the installed narrowband filtering devices is denoted as... Where λ P′ Let τ be the center wavelength of the P′-th narrowband filter device. P′ Let be the full width at half maximum (FWHM) of the P′-th narrowband filter device; the Q polarization channels are denoted as 1,...,Q′,...,Q, and are used to mount linear polarization filter devices.

[0113] In this embodiment, a broadband filter device mounted on turntable 7-2 has a filtering range of 400nm-800nm. In addition, seven narrowband filters are mounted on turntable 7-2, with center wavelengths of 450nm, 500nm, 549nm, 591nm, 640nm, 700nm, and 750nm, respectively. All narrowband filters have a full width at half maximum (FWHM) of 5nm. Simultaneously, four linearly polarized filters are also mounted on turntable 7-2, with polarization angles of 0°, 45°, 90°, and 135°. After obtaining image information from the four polarization channels, the polarization components (S0, S1, S2, S3) of the target imaging scene 1 can be calculated using the following formula:

[0114] S0=I0+I 90

[0115] S1=I0-I 90

[0116] S2=I 45 -I 135

[0117] S3 = I R -I L ,

[0118] Where I represents light intensity, S0 represents total incident light intensity, S1 represents the light intensity difference between the x and y components, S2 represents the light intensity difference between the 45° and 135° polarization components, and S3 represents the light intensity difference between the left-hand and right-hand circular polarization components.

[0119] In this composite imaging system, photodetector 8 is used to receive image information to obtain and store dispersive spectral images. It is insensitive to wavelength λ (i.e., a grayscale camera is used). The size of each pixel on photodetector 8 is Δ, and different pixels are represented by (n′, m′). In this embodiment, the photodetector 8 is a Hamamatsu C15550-22UPORCA-Quest2q CMOS camera. It has 4096×2304 pixels, and the side length of each pixel is 4.6μm, approximately half the side length of the reflective unit of the digital micromirror device 3.

[0120] In this composite imaging system, the control device 9 includes a display and a central processing unit. The central processing unit is electrically connected to both the digital micromirror chip 3 and the motor 7-1 to control the status of each micromirror and the rotation angle of the output shaft of the motor 7-1, respectively. The display is electrically connected to the central processing unit and is used to display seven modes: pushbroom spectral imaging, staring spectral imaging, transform spectral imaging, snapshot spectral imaging, pushbroom spectral polarization imaging, transform spectral polarization imaging, and snapshot spectral polarization imaging, for the user to select. It is also used to display the imaging results and image information received by the photodetector 8.

[0121] See Figure 1 The signal light emitted or reflected by the target imaging scene 1 enters the surface of the digital micromirror image chip 3 through the imaging lens 2, forming a primary image on the surface of the digital micromirror image chip 3. The digital micromirror image chip 3 spatially modulates the primary image, and the modulated information enters the collimating lens 4. The collimating lens 4 collimates the light onto the surface of the dispersive element 5, causing the light to disperse. The dispersed light then enters the converging lens 6. Next, the filter device installed on the turntable 7-2 selects different channels for the light beam. Combined with the different modulation methods of the digital micromirror image chip 3, seven different imaging modes (pushbroom spectral imaging, staring spectral imaging, transform spectral imaging, snapshot spectral imaging, pushbroom spectral polarization imaging, transform spectral polarization imaging, and snapshot spectral polarization imaging) can be realized. Finally, the photodetector 8 receives and saves the image information. Throughout the process, the central control processor coordinates the control of the digital micromirror image chip 3, the spectral polarization modulator 7, and the photodetector 8, as well as the reception, storage, and processing of image information.

[0122] The physical model of the composite imaging system will be further disclosed below to enable those skilled in the art to gain a deeper understanding of the operating mechanism and technical effects of the composite imaging system.

[0123] Let's assume that the signal light from target imaging scene 1, after entering the system and passing through imaging lens 2, has a spectral density of f0(x,y; λ), where x and y represent spatial dimensions, and λ represents the spectral dimension (i.e., wavelength). The spectral density after selective reflection T(x,y) by digital micromirror chip 3 is:

[0124] f1(x,y;λ)=f0(x,y;λ)T(x,y),

[0125] Subsequently, the spectral density f2(x,y;λ) of the signal light after passing through the collimating lens 4, the dispersive element 5, and the converging lens 6 in sequence is expressed as follows:

[0126]

[0127] The Dirac function δ describes the magnification (or reduction) of the optical lens (including the collimating lens 4 and the converging lens 6) and the linear dispersion of the dispersive element 5, while α is the scaling factor.

[0128] When signal light enters the surface of the spectral polarization modulator 7, the following situation will occur due to the differences in the filtering components installed on the turntable 7-2:

[0129] (1) When the broadband filter device installed on the turntable 7-2 is located on the propagation path of the signal light of the target imaging scene 1, the continuous image (i.e., the dispersive spectral image) on the photodetector 8 is represented as:

[0130]

[0131] (2) When the narrowband filter device installed on the spectral channel P′ of the turntable 7-2 is located on the propagation path of the signal light of the target imaging scene 1, the continuous image on the photodetector 8 is represented as:

[0132]

[0133] (3) When the linear polarization filter installed on the polarization channel Q′ of the turntable 7-2 is located on the propagation path of the signal light of the target imaging scene 1, the continuous image on the photodetector 8 is represented as:

[0134] g(x,y)=∫f0(x+α(λ-λ c ),y;λ)T(x+α(λ-λ c ),y)dλ.

[0135] Since photodetector 8 samples in two dimensions x and y, the measurement at position (n′, m′) on photodetector 8 can be expressed as follows in the presence of noise ω:

[0136]

[0137] For a reflective unit composed of several micromirrors, the side length of each reflective unit is sd, which is s times the side length of the micromirror. Assume sd = qΔ, where q is a positive integer. That is, the side length of the reflective unit on the digital micromirror chip 3 is q times the side length of each pixel on the photodetector 8. Therefore, the selective reflection effect of the digital micromirror chip 3 can be represented as the on / off state of the micromirror reflective unit at position (n, m), i.e.

[0138]

[0139] Among them, T nm It is a matrix composed of 0s and 1s, corresponding to the switching states of different reflective units on the digital micromirror chip 3. The measured value at position (n′, m′) on the photodetector 8 can be rewritten as:

[0140]

[0141] Express f0(x,y;λ) in discretized form f uvw The discretization of T(x,y) is represented as T uv Where u and v represent spatial dimensions, and w represents spectral dimensions. Then the measurement value at position (n′, m′) on photodetector 8 can be expressed as:

[0142]

[0143] Where H is the linear transformation matrix of the forward model of the composite imaging system, derived from T nm Generates according to certain rules. It is usually assumed that f is sparse in a certain transform domain to facilitate solving in snapshot spectral imaging, i.e., f = Wθ, where W is the sparse transform matrix and θ is the vector representing the basis of the sparse transform matrix. Then we have...

[0144] g n′m′ =(HWθ) n′m′ +ω n′m′ =(Aθ) n′m′ +ω n′m′ ,

[0145] Where A = HW.

[0146] See Figures 5 to 11 The following will further disclose a spectral polarization multi-mode composite imaging method using the spectral polarization multi-mode composite imaging system of this embodiment, which includes the following steps:

[0147] Users can choose one of the following seven modes: pushbroom spectral imaging, staring spectral imaging, transform spectral imaging, snapshot spectral imaging, pushbroom spectral polarization imaging, transform spectral polarization imaging, and snapshot spectral polarization imaging.

[0148] If pushbroom spectral imaging is selected, the pushbroom spectral imaging method is executed to obtain imaging results;

[0149] If staring spectral imaging is selected, the staring spectral imaging method will be executed to obtain the imaging results;

[0150] If transform spectral imaging is selected, the transform spectral imaging method will be executed to obtain the imaging results;

[0151] If snapshot spectral imaging is selected, the snapshot spectral imaging method will be executed to obtain the imaging results;

[0152] If pushbroom spectral polarization imaging is selected, the pushbroom spectral polarization imaging method will be executed to obtain the imaging results;

[0153] If transform-type spectral polarization imaging is selected, the transform-type spectral polarization imaging method will be executed to obtain the imaging results;

[0154] If snapshot spectral polarization imaging is selected, the snapshot spectral polarization imaging method will be executed to obtain the imaging results.

[0155] Figures 5 to 11The modulation mode of the digital micromirror chip 3, the gating channel of the spectral-polarization modulator 7, and the data format obtained by the photodetector 8 are all depicted. The row with number 3 in the figure is the modulation mode of the digital micromirror chip 3, the row with number 7 is the gating channel of the spectral-polarization modulator 7, and the row with number 8 is the data format obtained by the photodetector 8.

[0156] See Figure 5 In this embodiment, the pushbroom spectral imaging method includes the following steps:

[0157] S11: Adjust the rotation angle of the output shaft of motor 7-1 by controlling device 9 so that the broadband filter device is located on the propagation path of the signal light of the target imaging scene 1.

[0158] S12: Select multiple micromirror columns of the digital micromirror chip 3 and divide the multiple micromirror columns into several column units.

[0159] S13: The light transmission of each column unit is controlled separately by the control device 9, and the dispersive spectrum image corresponding to the light transmission of each column unit is obtained by the photodetector 8; for the m1 column units of the digital micromirror chip 3 m1 = 6, when the j-th column cell c j When all micromirrors are in the light-transmitting state (i.e., positively polarized), matrix T nm All elements in the j-th column have a value of 1, while all other elements have a value of 0. Photodetector 8 captures m1 column cells. The dispersive spectra corresponding to the forward polarization are denoted as follows: There are 1 sheet in total.

[0160] S14: Store all the dispersive spectral images obtained in step S13 in BIL (band interleaved by line) format, and then convert the BIL format into BSQ (band sequential) format by extracting the spectral information of the spatial location to represent the spatial distribution of the target imaging scene 1 in different bands and obtain the imaging results.

[0161] In the BIL format, each dispersive spectral image has a horizontal spectral dimension λ and a vertical spatial dimension y. The spectral information of the spatial location (x,y) can be directly extracted from the BIL format by calibration, and then the BIL format can be converted into the BSQ format. The BSQ format represents the spatial distribution of the target imaging scene 1 in different bands.

[0162] See Figure 6 In this embodiment, the staring spectral imaging method includes the following steps:

[0163] S21: Select multiple micromirror columns of the digital micromirror chip 3, divide the multiple micromirror columns into several column units, and then control all column units to transmit light through the control device 9. Specifically, make m1 = 6 column units c1,...,c of the digital micromirror chip 3 m ...,c6 are all positively biased. At this time, matrix T nm All elements satisfy t ij =1.

[0164] S22: The rotation angle of the output shaft of motor 7-1 is adjusted by the control device 9 to position each narrowband filter device on the propagation path of the signal light. When each narrowband filter device is on the propagation path of the signal light, the corresponding dispersive spectral image is obtained by the photodetector 8. Finally, the photodetector 8 captures the spectral images corresponding to all seven narrowband filter devices, denoted as S22. There are 7 in total.

[0165] S23: Convert all the dispersive spectral images obtained in step S22 into BSQ format to obtain the imaging results.

[0166] See Figure 7 In this embodiment, the transform-based spectral imaging method includes the following steps:

[0167] S31: Adjust the rotation angle of the output shaft of motor 7-1 by controlling device 9 so that the broadband filter device is located on the propagation path of the signal light of the target imaging scene 1.

[0168] S32: Select multiple micromirror columns of digital micromirror chip 3, and divide the multiple micromirror columns into m1 = 6 column units.

[0169] S33: Set a non-singular matrix of order 6 over the binary field, and make the value of all elements in the j-th column of the i-th transformation matrix equal to the value of the element in the i-th row and j-th column of the non-singular matrix to generate 6 transformation matrices; in this embodiment, the non-singular matrix is ​​the Hadamard matrix.

[0170] S34: The state of all micromirrors in the column unit obtained in step S32 is controlled by the control device 9 according to each transformation matrix, and the dispersive spectral image corresponding to each transformation matrix is ​​obtained by the photodetector 8. Then, the photodetector 8 captures the dispersive spectral images corresponding to 6 different patterns of the digital micromirror chip 3, denoted as There are 6 in total.

[0171] S35: Convert all dispersive spectral images obtained in step S34 into BIL format spectral data cubes using the format conversion formula to obtain the imaging results. In this embodiment, the format conversion formula is:

[0172]

[0173] Where g″′ is composed of Form column vectors Since ω is a non-singular matrix, and ω is the noise term, the BIL-formatted spectral data cube is:

[0174]

[0175] It is then converted to BSQ format to obtain imaging results.

[0176] See Figure 8 In this embodiment, the snapshot spectral imaging method includes the following steps:

[0177] S41: Adjust the rotation angle of the output shaft of motor 7-1 by controlling device 9 so that the broadband filter device is located on the propagation path of the signal light of the target imaging scene 1.

[0178] S42: Select multiple rows and columns of micromirrors from the digital micromirror chip 3 to obtain the working area; in this embodiment, m1 = 6 column reflection units and n1 = 4 row reflection units are selected as the working area.

[0179] S43: Construct an encoding matrix on the binary domain that adapts to the working area selected in step S42 and satisfies the constraint isometric condition. Use the manipulation device 9 to control the state of all micromirrors in the working area according to the encoding matrix; wherein, the constraint isometric condition refers to... This holds true for all sparse vectors θ of size S. Where δ S It is the constraint equidistant coefficient of the encoding matrix A. S sparsity means that the sparse vector θ has at most S non-zero terms.

[0180] S44: Obtain a dispersive spectral image through photodetector 8.

[0181] S45: Determine whether the number of currently acquired dispersive spectral images is equal to the specified value.

[0182] If so, proceed to the next step;

[0183] If not, then return to step S43.

[0184] In this embodiment, the specified value is set to 2, thereby obtaining two dispersive spectral images, denoted as g. n′m′ and

[0185] S46: Using all currently acquired dispersive spectral images, model the spectral data cube reconstruction method as a least-squares estimation problem with a regularization term; that is, let the spectral data cube be:

[0186]

[0187] S47: Solve the least squares estimation problem to obtain the distribution of spectral data cube estimates, and use this distribution as the imaging result. This can be solved using gradient projection sparse reconstruction or a two-step iterative thresholding method. Modeling it as a least squares estimation problem with regularization terms is an existing technique, which those skilled in the art can learn about by consulting relevant books on optimization models and algorithms; it will not be elaborated upon here.

[0188] See Figure 9 In this embodiment, the pushbroom spectral polarization imaging method includes the following steps:

[0189] S51: Adjust the rotation angle of the output shaft of motor 7-1 by controlling device 9 so that one of the linear polarization filter devices is located on the propagation path of the signal light of target imaging scene 1.

[0190] S52: Select multiple micromirror columns of the digital micromirror chip 3 and divide the multiple micromirror columns into several column units.

[0191] S53: Control the light transmission of each column unit by controlling the control device 9, and obtain the dispersive spectrum image corresponding to the light transmission of each column unit by the photodetector 8.

[0192] S54: Store all the dispersive spectral images obtained in step S53 in BIL format, and then convert the BIL format into BSQ format by extracting the spectral information of the spatial location to represent the spatial distribution of the target imaging scene 1 in different bands.

[0193] S55: Determine whether all linear polarization filter devices on turntable 7-2 have been traversed.

[0194] If so, proceed to the next step;

[0195] If not, the rotation angle of the output shaft of motor 7-1 is adjusted by manipulating device 9 so that the next linear polarization filter device is located on the propagation path of the signal light of the target imaging scene 1, and then the process is reversed to execute step S52.

[0196] S56: Cluster all the currently acquired BSQ format dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain the imaging results.

[0197] See Figure 10 In this embodiment, the transform-type spectral polarization imaging method includes the following steps:

[0198] S61: Adjust the rotation angle of the output shaft of motor 7-1 by controlling device 9 so that one of the linear polarization filter devices is located on the propagation path of the signal light of the target imaging scene 1.

[0199] S62: Select multiple micromirror columns of the digital micromirror chip 3, and divide the multiple micromirror columns into several column units.

[0200] S63: Set a non-singular matrix in the binary field with an order equal to the number of column units obtained in step S62. Let the value of all elements in the j-th column of the i-th transformation matrix be equal to the value of the element in the i-th row and j-th column of the non-singular matrix, so as to generate a transformation matrix with a number equal to the number of column units obtained in step S62.

[0201] S64: The state of all micromirrors in the column unit obtained in step S62 is controlled by the control device 9 according to each transformation matrix, and the dispersive spectrum image corresponding to each transformation matrix is ​​obtained by the photodetector 8.

[0202] S65: Determine whether all linear polarization filter devices on turntable 7-2 have been traversed.

[0203] If so, proceed to the next step;

[0204] If not, the rotation angle of the output shaft of motor 7-1 is adjusted by manipulating device 9 so that the next linear polarization filter device is located on the propagation path of the signal light of the target imaging scene 1, and then the process is reversed to execute step S62.

[0205] S66: Cluster all currently acquired dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain imaging results.

[0206] See Figure 11 In this embodiment, the snapshot-type spectral polarization imaging method includes the following steps:

[0207] S71: Adjust the rotation angle of the output shaft of motor 7-1 by controlling device 9 so that one of the linear polarization filter devices is located on the propagation path of the signal light of target imaging scene 1.

[0208] S72: Select multiple rows and columns of micromirrors from the digital micromirror chip 3 to obtain the working area.

[0209] S73: Construct an encoding matrix on the binary domain that is compatible with the working area selected in step S72 and satisfies the constraint equidistant condition, and control the state of all micromirrors in the working area according to the encoding matrix by manipulating device 9.

[0210] S74: Obtain a dispersive spectral image through photodetector 8;

[0211] S75: Determine whether all linear polarization filter devices on turntable 7-2 have been traversed.

[0212] If so, proceed to the next step;

[0213] If not, the rotation angle of the output shaft of motor 7-1 is adjusted by manipulating device 9 so that the next linear polarization filter device is located on the propagation path of the signal light of the target imaging scene 1, and then the process is reversed to execute step S72.

[0214] S76: Cluster all currently acquired dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain imaging results.

[0215] As can be seen from the disclosed physical model and imaging method, in this embodiment of the spectral polarization multi-mode composite imaging system, since the digital micromirror chip 3, dispersive element 5, and spectral-polarization modulator 7 are sequentially arranged along the signal light propagation direction of the target imaging scene, when a micromirror in the micromirror matrix is ​​in a light-transmitting state, the signal light received by this micromirror can be introduced into the dispersive element 5, and vice versa. The signal light introduced into the dispersive element 5 is dispersed by the dispersive element 5 to form dispersed light. Since a broadband filter, several narrowband filters, and several linear polarization filters are arranged in a ring on the turntable 7-2 of the spectral-polarization modulator 7, under the action of the motor 7-1 of the spectral-polarization modulator 7, one of the filters can be positioned on the propagation path of the signal light. Therefore, with the combination of the digital micromirror chip 3, dispersive element 5, and spectral-polarization modulator 7, spectral polarization imaging of multiple channels can be realized. The imaging information can be received by the photodetector 8, ultimately realizing the acquisition of the spectral and polarization information of the target.

[0216] Meanwhile, since this composite imaging system also includes a control device 9 to control the state of each micromirror and the rotation angle of the output shaft of motor 7-1, it can achieve pushbroom, staring, transformation, and snapshot spectral imaging in addition to acquiring the spectral and polarization information of the target. Furthermore, due to the linear polarization filter, pushbroom, transformation, and snapshot spectral imaging can be combined with polarization imaging for spectral polarization imaging, achieving a total of seven different imaging modes. Under this multi-mode spectral polarization imaging, different spectral polarization imaging modes can be selected for different target scenes to specifically adjust the three resolutions, ultimately achieving highly flexible, multi-scene adaptable adaptive spectral polarization imaging, meeting the technical requirement of simultaneously achieving optimal resolution across the three resolutions in spectral polarization imaging technology.

[0217] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer" and other terms indicating direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0218] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0219] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A spectral polarization multi-mode composite imaging system, characterized in that, The composite imaging system includes a control device (9) and signal light propagation components arranged sequentially along the target imaging scene (1): The digital micromirror chip (3) contains a micromirror matrix composed of multiple micromirrors, and each micromirror has two states: light transmission and light blocking. The state of each micromirror is controlled individually. Dispersive element (5); The spectral polarization modulator (7) consists of a motor (7-1) and a turntable (7-2) mounted on the output shaft of the motor (7-1). The turntable (7-2) is provided with multiple filter elements arranged in a ring. The multiple filter elements consist of a broadband filter element, several narrowband filter elements and several linear polarization filter elements. The motor (7-1) is used to drive the turntable (7-2) to rotate so that one of the filter elements is located on the propagation path of the signal light. Photodetector (8); The control device (9) is electrically connected to both the digital micromirror chip (3) and the motor (7-1) to control the state of each micromirror and the rotation angle of the output shaft of the motor (7-1) respectively.

2. The spectral polarization multi-mode composite imaging system according to claim 1, characterized in that, The composite imaging system further includes an imaging lens (2), a collimating lens (4), and a converging lens (6). The imaging lens (2), the digital micromirror chip (3), the collimating lens (4), the dispersive element (5), the converging lens (6), the spectral-polarization modulator (7), and the photodetector (8) are arranged sequentially along the direction of signal light propagation.

3. A method for multi-mode composite imaging with spectral polarization, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: Users can choose one of the following seven modes: pushbroom spectral imaging, staring spectral imaging, transform spectral imaging, snapshot spectral imaging, pushbroom spectral polarization imaging, transform spectral polarization imaging, and snapshot spectral polarization imaging. If pushbroom spectral imaging is selected, the pushbroom spectral imaging method is executed to obtain imaging results; If staring spectral imaging is selected, the staring spectral imaging method will be executed to obtain the imaging results; If transform spectral imaging is selected, the transform spectral imaging method will be executed to obtain the imaging results; If snapshot spectral imaging is selected, the snapshot spectral imaging method will be executed to obtain the imaging results; If pushbroom spectral polarization imaging is selected, the pushbroom spectral polarization imaging method will be executed to obtain the imaging results; If transform-type spectral polarization imaging is selected, the transform-type spectral polarization imaging method will be executed to obtain the imaging results; If snapshot spectral polarization imaging is selected, the snapshot spectral polarization imaging method will be executed to obtain the imaging results.

4. A pushbroom spectral imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S11: Adjust the rotation angle of the output shaft of the motor (7-1) by means of the control device (9) so that the broadband filter device is located on the propagation path of the signal light of the target imaging scene (1); S12: Select multiple micromirror columns of the digital micromirror chip (3) and divide the multiple micromirror columns into several column units; S13: The control device (9) is used to control the light transmission of each column unit respectively, and the photodetector (8) is used to obtain the dispersive spectrum image corresponding to the light transmission of each column unit; S14: Store all the dispersive spectral images obtained in step S13 in BIL format, and then convert the BIL format into BSQ format by extracting the spectral information of the spatial location to represent the spatial distribution of the target imaging scene (1) in different bands and obtain the imaging result.

5. A staring spectral imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S21: Select multiple micromirror columns of the digital micromirror chip (3), divide the multiple micromirror columns into several column units, and then control all column units to transmit light through the control device (9); S22: The rotation angle of the output shaft of the motor (7-1) is adjusted by the control device (9) so that each narrowband filter device is located on the propagation path of the signal light, and the corresponding dispersive spectrum image is obtained by the photodetector (8) when each narrowband filter device is located on the propagation path of the signal light. S23: Convert all the dispersive spectral images obtained in step S22 into BSQ format to obtain imaging results.

6. A transformation-based spectral imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S31: Adjust the rotation angle of the output shaft of the motor (7-1) through the control device (9) so that the broadband filter device is located on the propagation path of the signal light of the target imaging scene (1); S32: Select multiple micromirror columns of the digital micromirror chip (3) and divide the multiple micromirror columns into several column units; S33: Set a nonsingular matrix over the binary field whose order is the number of column units obtained in step S32, and let the first... i The transformation matrix of the nth transformation matrix j The value of all elements in the column is equal to the value of the nonsingular matrix. i Line number j The element values ​​of the column are used to generate a transformation matrix with a number equal to the number of column units obtained in step S32; S34: The control device (9) controls the state of all micromirrors in the column unit obtained in step S32 according to each transformation matrix, and obtains the dispersive spectral image corresponding to each transformation matrix through the photodetector (8); S35: Use the format conversion formula to convert all the dispersive spectral images obtained in step S34 into BIL format spectral data cubes to obtain imaging results.

7. A snapshot-type spectral imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S41: Adjust the rotation angle of the output shaft of the motor (7-1) by means of the control device (9) so that the broadband filter device is located on the propagation path of the signal light of the target imaging scene (1); S42: Select multiple rows and columns of micromirrors from the digital micromirror chip (3) to obtain the working area; S43: Construct an encoding matrix on the binary domain that is adapted to the working area selected in step S42 and satisfies the constraint equidistant condition, and use the control device (9) to control the state of all micromirrors in the working area according to the encoding matrix; S44: Obtain a dispersive spectral image through a photodetector (8); S45: Determine whether the number of currently acquired dispersive spectral images is equal to the specified value. If so, proceed to the next step; If not, then return to step S43; S46: Using all the dispersive spectral images currently available, model the spectral data cube reconstruction method as a least squares estimation problem with a regularization term; S47: Solve the least squares estimation problem to obtain the distribution of spectral data cube estimates, and use the distribution of spectral data cube estimates as the imaging result.

8. A pushbroom-type spectral polarization imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S51: Adjust the rotation angle of the output shaft of the motor (7-1) by means of the control device (9) so that one of the linear polarization filter devices is located on the propagation path of the signal light of the target imaging scene (1); S52: Select multiple micromirror columns of the digital micromirror chip (3) and divide the multiple micromirror columns into several column units; S53: Control the light transmission of each column unit through the control device (9), and obtain the dispersive spectrum image corresponding to the light transmission of each column unit through the photodetector (8); S54: Store all the dispersive spectral images obtained in step S53 in BIL format, and then convert the BIL format into BSQ format by extracting the spectral information of the spatial location to represent the spatial distribution of the target imaging scene (1) in different bands. S55: Determine whether all linear polarization filter devices on the turntable (7-2) have been traversed. If so, proceed to the next step; If not, the rotation angle of the output shaft of the motor (7-1) is adjusted by the control device (9) so that the next linear polarization filter device is located on the propagation path of the signal light of the target imaging scene (1), and then the step S52 is executed in reverse. S56: Cluster all the currently acquired BSQ format dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain the imaging results.

9. A transformation-type spectral polarization imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S61: Adjust the rotation angle of the output shaft of the motor (7-1) by means of the control device (9) so that one of the linear polarization filter devices is located on the propagation path of the signal light of the target imaging scene (1); S62: Select multiple micromirror columns of the digital micromirror chip (3) and divide the multiple micromirror columns into several column units; S63: Set a nonsingular matrix over the binary field whose order is the number of column units obtained in step S62, and let the... i The transformation matrix of the nth transformation matrix j The value of all elements in the column is equal to the value of the nonsingular matrix. i Line number j The element values ​​of the column are used to generate a transformation matrix with a number equal to the number of column cells obtained in step S62; S64: The state of all micromirrors in the column unit obtained in step S62 is controlled by the control device (9) according to each transformation matrix, and the dispersive spectral image corresponding to each transformation matrix is ​​obtained by the photodetector (8); S65: Determine whether all linear polarization filter devices on the turntable (7-2) have been traversed. If so, proceed to the next step; If not, the rotation angle of the output shaft of the motor (7-1) is adjusted by the control device (9) so that the next linear polarization filter device is located on the propagation path of the signal light of the target imaging scene (1), and then the step S62 is executed in reverse. S66: Cluster all currently acquired dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain imaging results.

10. A snapshot-type spectral polarization imaging method, characterized in that, The spectral polarization multimode composite imaging system according to claim 1 or 2 includes the following steps: S71: Adjust the rotation angle of the output shaft of the motor (7-1) by means of the control device (9) so that one of the linear polarization filter devices is located on the propagation path of the signal light of the target imaging scene (1); S72: Select multiple rows and columns of micromirrors from the digital micromirror chip (3) to obtain the working area; S73: Construct an encoding matrix on the binary domain that is compatible with the working area selected in step S72 and satisfies the constraint equidistant condition, and use the control device (9) to control the state of all micromirrors in the working area according to the encoding matrix; S74: Obtain a dispersive spectral image through a photodetector (8); S75: Determine whether all linear polarization filter devices on the turntable (7-2) have been traversed. If so, proceed to the next step; If not, the rotation angle of the output shaft of the motor (7-1) is adjusted by the control device (9) so that the next linear polarization filter device is located on the propagation path of the signal light of the target imaging scene (1), and then the step S72 is executed in reverse. S76: Cluster all currently acquired dispersive spectral images according to polarization channels to obtain spectral data cubes under different polarization states, and obtain imaging results.

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