CN115993327A

CN115993327A - Spectral imaging system

Info

Publication number: CN115993327A
Application number: CN202111207538.6A
Authority: CN
Inventors: 刘舒扬; 王天鹤; 张晨; 赵安娜; 张云昊; 周志远; 潘建旋; 姜洪妍; 王才喜
Original assignee: Tianjin Jinhang Institute of Technical Physics
Current assignee: Tianjin Jinhang Institute of Technical Physics
Priority date: 2021-10-18
Filing date: 2021-10-18
Publication date: 2023-04-21

Abstract

The invention provides a spectrum imaging system which comprises a pixel photosensitive unit and a spectrum imaging unit, wherein the spectrum imaging unit comprises a narrow-band filter film, a transition layer, a first stop filter film, a second stop filter film and a third stop filter film, the narrow-band filter film is integrally deposited and grown on the pixel photosensitive unit, the transition layer is integrally deposited and grown on the narrow-band filter film, the transition layer is used for transiting two film systems of the narrow-band filter film and the first stop filter film, the first stop filter film is integrally deposited and grown on the narrow-band filter film, the first stop filter film is used for stopping a first interference wave band, the second stop filter film is arranged on the first stop filter film, the second stop filter film is used for stopping a second interference wave band, the third stop filter film is arranged on the second stop filter film, and the third stop filter film is used for stopping a third interference wave band. By applying the technical scheme of the invention, the technical problems of low spectral transmittance and low quantum efficiency caused by a cut-off filter film attaching mode in the prior art are solved.

Description

Spectral imaging system

Technical Field

The invention relates to the technical field of spectrum imaging, in particular to a spectrum imaging system.

Background

The hyperspectral imaging system (Hyper Spectral Imaging, HSI for short) can obtain a three-dimensional spectrum image with a characteristic of 'map unification' formed by two-dimensional space image information and one-dimensional spectrum information, and can observe the space information of two-dimensional distribution and the spectrum information on each pixel point.

The image space information reflects external characteristics such as the size, shape, defects and the like of the target object, and the spectrum information can reflect physical and chemical components of the target object. Therefore, physical and chemical information such as material, components and the like can be identified by analyzing and processing the spectrum information, and related positions and ranges can be identified rapidly and intuitively by the space information of the image.

In a classical HSI system, because the system is based on a single discrete device, in order to ensure spatial resolution and spectral resolution, optical devices such as an objective lens, a diaphragm, a collimator, various lenses and the like must be introduced, and focusing and collimation problems among various devices must be considered, so that the complexity, the volume and the cost of the traditional HSI system are very high, and the application range is greatly limited.

Furthermore, in order to complete the filtering out of the target characteristic spectrum segment, the target distinction is realized, and the narrow-band filter film is integrated on the spectrum imaging chip, so that the tunable filtering at the center of the required wave band can be realized (as shown in fig. 6, the center wavelength of the narrow-band filter film is tunable within a certain range). However, due to the limitation of the refractive index of the existing high-low materials, the spectral bandwidth range cannot cover the full spectrum (as shown in fig. 6, the cut-off bandwidth is less than 200 nm), and the interference of signals with other wave bands exists as shown in fig. 7, and the interference has other wave band influences besides the required wave band. An external cut-off filter film (as shown in fig. 8) is required to cut off the interference band. The existing external cut-off filter film is coated separately and then attached to the image sensor, so that the spectral transmittance is reduced, the quantum efficiency is reduced, and the imaging effect is affected.

Disclosure of Invention

The invention provides a spectrum imaging system which can solve the technical problems of low spectrum transmittance and low quantum efficiency caused by a cut-off filter film attaching mode in the prior art.

According to an aspect of the present invention, there is provided a spectral imaging system including a pixel photosensitive unit for realizing image acquisition and data readout and a spectral imaging unit including: the narrow-band filter film is integrally deposited and grown on the pixel photosensitive unit and is used for realizing the tunability of the central wavelength of a required wave band; the transition layer is integrally deposited and grown on the narrow-band filter film and is used for transiting two film systems of the narrow-band filter film and the first cut-off filter film; the first cut-off filter film is integrally deposited and grown on the narrow-band filter film and is used for cutting off a first interference wave band; the second cut-off filter film is arranged on the first cut-off filter film and is used for cutting off a second interference wave band, and the second interference wave band is different from the first interference wave band; the third cut-off filter film is arranged on the second cut-off filter film and used for cutting off a third interference wave band, and the third interference wave band is different from the first interference wave band and the second interference wave band.

Further, the second cut-off filter film is deposited and grown on the first cut-off filter film in an integrated manner, and the third cut-off filter film is deposited and grown on the second cut-off filter film in an integrated manner.

Further, the second cut-off filter film is integrally deposited and grown on the first cut-off filter film, and the third cut-off filter film is adhered and arranged on the second cut-off filter film.

Further, the second cut-off filter film is stuck on the first cut-off filter film, and the third cut-off filter film is stuck on the second cut-off filter film.

Further, the spectrum imaging unit further comprises a matching layer, the matching layer is integrally deposited and grown on the pixel photosensitive unit, and the matching layer is used for transiting optical admittances among the photosensitive unit, the narrow-band filter film, the transition layer, the first cut-off filter film, the second cut-off filter film and the third cut-off filter film so as to improve the peak transmittance of the central wavelength; the narrow-band filter film is integrally deposited and grown on the matching layer.

Further, the film system structure of the spectrum imaging unit is sub|HLH (LH) ≡S ₁ 2nL(HL)^S ₁ HL n ₁ (W1)^S ₂ n ₂ (W2)^S ₃ n ₃ (W3)^S ₄ I Air, HL is the film structure of the matching layer, H (LH) ≡S ₁ 2nL(HL)^S ₁ H is the film system structure of the narrow-band filter film, L is the film system structure of the transition layer, n ₁ (W1)^S ₂ A film system structure of a first cut-off filter film, n ₂ (W2)^S ₃ A film system structure of a second cut-off filter film, n ₃ (W3)^S ₄ The film system structure of the third stop filter film comprises a high refractive index material and a low refractive index material, wherein H is the high refractive index material, L is the low refractive index material and S is ₁ 、S ₂ 、S ₃ And S is ₄ For the number of overlapping times, n is the film thickness adjustment coefficient of the narrow-band filter film, n ₁ For the film thickness adjustment coefficient of the first cut-off filter film, n ₂ For adjusting the coefficient of the film thickness of the second cut-off filter film, n ₃ And (3) adjusting the coefficient for the thickness of the film layer of the third stop filter film.

Further, any one of the cut-off filter films is prepared by alternately depositing a high refractive index material and a low refractive index material, and the high refractive index material of any one of the cut-off filter films comprises Ta ₂ O ₅ 、Ti ₃ O ₅ 、TiO ₂ 、Si ₃ N ₄ Or Nb (Nb) ₂ O ₅ The low refractive index material of any of the cut-off filter films comprises SiO ₂ 、MgF ₂ And Al ₂ O ₃ At least one of them.

Further, the narrow-band filter film comprises a plurality of FP cavity structures, the plurality of FP cavity structures are formed at one time by adopting a semiconductor process, any one FP cavity structure comprises a first reflecting mirror, a light-transmitting layer and a second reflecting mirror which are sequentially overlapped from bottom to top, the plurality of FP cavity structures are distributed in a mosaic mode, the heights of the light-transmitting layers of the plurality of FP cavity structures along any one row of narrow-band filter film are different, and the heights of the light-transmitting layers of the plurality of FP cavity structures along any one row of narrow-band filter film are different; or the plurality of FP cavity structures are distributed in a line scanning mode, the heights of the light transmission layers of the plurality of FP cavity structures along any one row of narrow-band filter films are identical, and the heights of the light transmission layers of the plurality of FP cavity structures along any one row of narrow-band filter films are different.

Further, the film thickness adjustment coefficient can be obtained according to the following steps: determining a spectrum section to be cut off of any cut-off filter film; calculating and obtaining the central wavelength of the spectrum segment to be cut according to the first boundary threshold value and the second boundary threshold value of the spectrum segment to be cut; and determining the film thickness adjustment coefficient of any cut-off filter film according to the center wavelength of the to-be-cut-off spectrum and the center wavelength of the narrow-band filter film.

Further, the center wavelength of the spectrum to be cut-off can be determined according to

Is obtained by, wherein lambda ₀ Lambda is the center wavelength of the spectrum to be cut off ₁ For a first boundary threshold, lambda, of the spectral band to be cut-off ₂ Is a second boundary threshold for the portion of spectrum to be cut off.

Further, the film thickness adjustment coefficient n of the cut-off filter film can be determined according to

Is obtained, wherein lambda is the center wavelength of the narrow-band filter film, n=n ₁ 、n ₂ Or n ₃ 。

Further, the spectral imaging system comprises a plurality of spectral imaging units, and the pixel photosensitive units are divided into a plurality of pixel areas along the direction of the spectral dimension; the narrow-band filter films of the plurality of spectrum imaging units are respectively deposited and grown on the plurality of pixel areas in one-to-one correspondence.

Further, the narrow-band filter film of any spectrum imaging unit comprises a plurality of FP cavity structures, the plurality of FP cavity structures are formed at one time by a semiconductor process, any FP cavity structure comprises a first reflecting mirror, a light-transmitting layer and a second reflecting mirror which are sequentially overlapped from bottom to top, the plurality of FP cavity structures are distributed in a line scanning mode, the heights of the light-transmitting layers of the plurality of FP cavity structures of the narrow-band filter film along the space dimension direction are identical, and the heights of the light-transmitting layers of the plurality of FP cavity structures of the narrow-band filter film along the spectrum dimension direction are different.

Further, the spectral imaging system comprises a first spectral imaging unit and a second spectral imaging unit, and the pixel photosensitive unit is divided into a first pixel area and a second pixel area along the direction of the spectral dimension; the narrow-band filter film of the first spectrum imaging unit is integrally deposited and grown on the first pixel area, and the narrow-band filter film of the second spectrum imaging unit is integrally deposited and grown on the second pixel area.

Further, the first spectrum imaging unit covers a spectrum range of 490nm to 620nm, and the second spectrum imaging unit covers a spectrum range of 650nm to 1000nm.

Further, the narrow-band filter film of the first spectrum imaging unit comprises a plurality of FP cavity structures, the plurality of FP cavity structures are formed at one time by adopting a semiconductor process, any FP cavity structure comprises a first reflecting mirror, a first light-transmitting layer and a second reflecting mirror which are sequentially overlapped from bottom to top, the plurality of FP cavity structures are distributed in a line scanning mode, the first reflecting mirror is prepared by alternately adopting a plurality of layers of high-reflectivity substances and a plurality of layers of low-reflectivity substances, the structure of the second reflecting mirror is the same as that of the first reflecting mirror, the first light-transmitting layer is formed by depositing and growing low-reflectivity substances, and the high-reflectivity substances comprise SI ₃ N ₄ The low reflectivity material comprises SIO ₂ 。

Further, the narrow band filter of the second spectral imaging unit comprises a plurality ofThe structure of the fourth reflector is the same as that of the third reflector, the second light-transmitting layer is formed by depositing and growing a low-reflectivity substance, wherein the high-reflectivity substance comprises alpha-SI, and the low-reflectivity substance comprises SIO ₂ 。

Further, the spectral imaging system comprises a third spectral imaging unit, a fourth spectral imaging unit and a fifth spectral imaging unit, and the pixel photosensitive unit is divided into a third pixel area, a fourth pixel area and a fifth pixel area along the spectral dimension direction; the narrow-band filter film of the third spectrum imaging unit integrally deposits and grows on the third pixel area, the narrow-band filter film of the fourth spectrum imaging unit integrally deposits and grows on the fourth pixel area, the narrow-band filter film of the fifth spectrum imaging unit integrally deposits and grows on the fifth pixel area.

Further, the spectrum range covered by the third spectrum imaging unit is 490 nm-620 nm, the spectrum range covered by the fourth spectrum imaging unit is 640 nm-800 nm, and the spectrum range covered by the fifth spectrum imaging unit is 800 nm-1000 nm.

Further, the narrow-band filter film of any spectrum imaging unit comprises a plurality of FP cavity structures, the plurality of FP cavity structures are formed at one time by adopting a semiconductor process, any FP cavity structure comprises a first reflector, a light passing layer and a second reflector which are sequentially overlapped from bottom to top, the plurality of FP cavity structures are distributed in a line scanning mode, the first reflector is prepared by alternately adopting a plurality of layers of high-reflectivity substances and a plurality of layers of low-reflectivity substances, the structure of the second reflector is the same as that of the first reflector, the first light passing layer is formed by depositing and growing low-reflectivity substances, and the high-reflectivity substances comprise SI ₃ N ₄ The low reflectivity material comprises SIO ₂ 。

Further, the spectrum imaging system comprises a plurality of spectrum imaging units and a plurality of color filter groups, the narrow-band filter films of the plurality of spectrum imaging units are sequentially deposited and grown on the pixel photosensitive units in an integrated mode at intervals, the plurality of color filter groups are sequentially deposited and grown on the pixel photosensitive units in an integrated mode at intervals, and one color filter group is arranged between any two adjacent spectrum imaging units.

Further, the line spacing between any two adjacent spectral imaging units is greater than or equal to 4.

Further, any color filter group includes an RGGB color filter structure, a RYYB color filter structure or an RGWB color filter structure.

Further, any one spectral imaging unit corresponds to one central wavelength, and the central wavelengths of the plurality of spectral imaging units sequentially taper.

Further, the spectrum imaging system comprises a first light splitting structure, the first light splitting structure comprises a plurality of spectrum imaging units and a plurality of polarization filtering structures, the narrow-band filtering films of the plurality of spectrum imaging units are integrally deposited and grown on the pixel photosensitive units, the plurality of polarization filtering structures are arranged on the pixel photosensitive units, and the polarization directions of the plurality of polarization filtering structures are different.

Further, the spectral imaging system further comprises a full-transmission spectrum structure, and the full-transmission spectrum structure is arranged on the pixel photosensitive unit.

Further, the first light splitting structure comprises four polarization filtering structures, and the polarization angles of the four polarization filtering structures are respectively 0 °, 45 °, 90 ° and 135 °.

Further, the plurality of spectral imaging units and the plurality of polarization filtering structures together form n×n structures, where n is a positive integer not less than 3.

Further, the spectral imaging system includes a plurality of first light splitting structures, the plurality of first light splitting structures being periodically arranged.

Further, the first light splitting structure is a 3*3 square structure, the first light splitting structure comprises four polarization filter structures, the four polarization filter structures are arranged at the center positions of the four outer side lengths of the square structure in a one-to-one correspondence mode, and the plurality of spectrum imaging units are arranged at other residual positions of the square structure.

Further, the first light splitting structure is a 3*3 square structure, the first light splitting structure comprises four polarization filter structures, the four polarization filter structures are arranged at the center of the outer side length of the square structure in a one-to-one correspondence mode, and the plurality of spectrum imaging units and the full-transmission spectrum structure are arranged at other residual positions of the square structure.

Further, the polarization angles of the four polarization filtering structures are 0 °, 45 °, 90 ° and 135 °, respectively.

Further, the spectrum imaging system comprises a plurality of second light splitting structures which are periodically arranged, any one of the second light splitting structures is of a 3*3 square structure, any one of the second light splitting structures comprises at least one wide spectrum filtering film structure, at least one spectrum imaging unit and four polarization filtering structures, the narrow band filtering film of the at least one spectrum imaging unit is integrally deposited and grows on the pixel photosensitive unit, the at least one wide spectrum filtering film structure and the four polarization filtering structures are arranged on the pixel photosensitive unit, the at least one wide spectrum filtering film structure and the at least one spectrum imaging unit are used for detecting spectrum characteristics before and after food maturation, and the polarization directions of the four polarization filtering structures are different.

Further, any one of the second light splitting structures comprises a broad spectrum filtering film structure, four spectral imaging units and four polarization filtering structures.

Further, any spectral imaging unit is of FP cavity structure.

Further, the broad spectrum filtering film structure is a band-pass broad spectrum filtering structure.

Further, the four spectral imaging units are arranged in the middle positions of the four outer side lengths of the square structure in a one-to-one correspondence mode, the wide-spectrum filtering film structure is arranged in the center of the square structure, and the four polarization filtering structures are arranged in the rest positions of the square structure.

Further, the spectrum imaging system also comprises an imaging lens, a data acquisition and processing module and a man-machine interaction module, wherein the imaging lens is arranged in the light incidence direction of the plurality of second light splitting structures, and the plurality of second light splitting structures are respectively connected with the data acquisition and processing module and the man-machine interaction module; the data acquisition and processing module is used for acquiring image data and judging the maturity according to the image data, and the man-machine interaction module is used for controlling the plurality of second light splitting structures to acquire images and sending the maturity information to the user side in real time.

Further, the spectrum imaging unit comprises a third light splitting structure, the third light splitting structure comprises a plurality of spectrum periods which are distributed periodically, any spectrum period comprises the spectrum imaging unit, narrow-band filter films of the spectrum imaging units are uniformly deposited and grown on the pixel photosensitive unit, and any narrow-band filter film comprises a plurality of FP cavity structures which are distributed in a mosaic mode.

Further, any spectrum period also comprises a plurality of polarization filtering structures with different polarization directions, and the plurality of polarization filtering structures and the plurality of FP cavity structures are arranged randomly.

Further, any one of the spectrum periods includes four polarization filter structures, and polarization angles of the four polarization filter structures are respectively 0 °, 45 °, 90 ° and 135 °.

Further, any one of the spectral periods further comprises at least one full-transmission spectrum segment structure, a plurality of polarization filtering structures, and a plurality of FP cavity structures arranged randomly.

Further, any one of the spectral periods further includes at least one bandpass wide spectrum filter structure, the plurality of polarization filter structures, and the plurality of FP cavity structures being randomly arranged.

Further, a plurality of polarization filtering structures are integrally deposited and grown on the pixel photosensitive unit.

Further, the spectral imaging system further comprises: the imaging lens group is used for transmitting light in the index of the spectral range of the third light splitting structure and converging the transmitted light on the pixel photosensitive unit; the readout circuit is connected with the pixel photosensitive unit; the control circuit comprises a processor and a communication module, and the processor is respectively connected with the reading circuit and the communication module.

Further, the spectral imaging system comprises at least one spectral imaging chip structure, any spectral imaging chip structure comprises a pixel photosensitive unit and a spectral imaging unit, the narrow-band filter film comprises a plurality of FP cavity structures distributed in a line scanning mode, the heights of the plurality of FP cavity structures along the spectral dimension direction are different, and the heights of the plurality of FP cavity structures along the spatial dimension direction are the same.

Further, the line scanning type spectrum imaging system comprises four spectrum imaging chip structures, and the spectrum ranges covered by the four spectrum imaging chip structures are 400-510 nm, 510-630 nm, 640-810 nm and 800-1000 nm in sequence.

Further, any spectrum imaging chip structure further comprises a plurality of color filter groups, the narrow-band filter films of the spectrum imaging units are sequentially and integrally deposited and grown on the pixel photosensitive units at intervals along the spectrum dimension direction, the color filter groups are sequentially and integrally deposited and grown on the pixel photosensitive units at intervals along the spectrum dimension direction, and one color filter group is arranged between any two adjacent spectrum imaging units.

Further, any color filter group is one of RGGB color filter structure, RYYB color filter structure or RGWB color filter structure.

Further, the spectral imaging system further comprises: the imaging lens group is used for transmitting light in the spectrum range index of the spectrum imaging system; the sensor adapter plate is used for carrying at least one spectrum imaging chip structure, and light transmitted by the imaging lens group is converged on the spectrum imaging chip structure on the sensor adapter plate; the embedded information processing board is connected with the sensor adapter plate and is used for supplying power to the sensor adapter plate, interacting signals and integrating the image information of the sensor adapter plate; the push-broom system is used for carrying the sensor adapter plate and the embedded information processing plate and moving the push-broom along the spectral dimension direction; the upper computer is respectively connected with the push-broom system and the embedded information processing board and is used for controlling the mobile push-broom of the push-broom system and acquiring a complete spectrum image according to the image information integrated by the embedded information processing board.

Further, the film system structure of the narrow-band filter film of any spectrum imaging chip structure is H (LH)/(S2 nL (HL)/(SH), n is a film thickness adjustment coefficient, S is the superposition times, H is a high refractive index material, L is a low refractive index material, the film thickness adjustment coefficients n of the four spectrum imaging chip structures are all different, and the film thickness adjustment coefficients n are divided into corresponding spectral band numbers.

Further, the range of the film thickness adjusting coefficient n corresponding to the four spectrum imaging chip structures is designed to be 0.745-1.557, 0.67-1.439, 0.643-1.425 and 0.652-1.437 in sequence along the direction of the spectrum dimension.

According to another aspect of the present invention, there is provided a method of manufacturing a spectral imaging system, the spectral imaging system being as described above, the method comprising: dividing a pixel photosensitive unit into a plurality of pixel areas along the direction of a spectrum dimension in sequence; and secondly, sequentially and respectively integrally depositing and growing a plurality of spectrum imaging units on the plurality of pixel areas, wherein the spectrum imaging units are used for realizing narrow-band filtering, and the plurality of spectrum imaging units respectively cover different spectrum ranges.

Further, the second step includes: 2.1, depositing a removing layer on the whole pixel area of the pixel photosensitive unit; 2.2, preparing a first spectral imaging unit along a spectral dimension direction, comprising: 2.21, removing the removing layer on the first pixel area corresponding to the first spectrum imaging unit; 2.22 preparing a first spectral imaging unit on the structure obtained in step 2.21 based on the raw material of the first spectral imaging unit; 2.3, removing the redundant removing layer, and integrally depositing the removing layer on the structure obtained in the step 2.2; 2.4, preparing a second spectral imaging unit along the spectral dimension, comprising: 2.41, removing the removing layer on the second pixel area corresponding to the second spectrum imaging unit; 2.42 preparing a second spectral imaging unit on the structure obtained in step 2.41 based on the starting material of the second spectral imaging unit; 2.5, and the like, adopting the same process as the steps 2.3-2.4 to sequentially prepare the rest spectrum imaging units.

According to still another aspect of the present invention, there is provided an imaging method of a line-scan spectral imaging system, the imaging method of the line-scan spectral imaging system performing spectral imaging using the line-scan spectral imaging system as described above, the imaging method of the line-scan spectral imaging system comprising: the upper computer controls the push-broom system to move along the direction of the spectrum dimension according to the preset push-broom speed; after the moving speed of the push-broom system is stable, the embedded information processing board acquires at least one spectrum imaging chip structure image at a preset frame rate, integrates the images and uploads the images to the upper computer; and the upper computer extracts a specific spectrum part in each frame of image and splices the specific spectrum part to acquire a complete spectrum image of the spectrum part in a scanning range.

Further, the preset push-broom speed satisfies V _min ≥L/f _frame Wherein V is _min For a minimum preset push-broom speed of the push-broom system, L is the length of the FP cavity step width mapped onto the imaging object plane, L/l=d/f _focus =2tan θ, l is the step width, D is the distance from the optical center of the imaging lens set to the object plane, f _focus For the focal length of the imaging lens group, θ is the angle of view of the imaging lens group, f _frame Is the image frame rate.

By applying the technical scheme of the invention, the spectrum imaging system is provided, the narrow-band filter film is integrally deposited and grown on the pixel photosensitive unit, the transition layer is integrally deposited and grown on the narrow-band filter film, the first cut-off filter film is integrally deposited and grown on the transition layer, no gap exists among the first cut-off filter film, the transition layer, the narrow-band filter film and the pixel photosensitive unit, the spectrum transmittance is high, the energy loss is reduced, the one-time preparation process is integrally formed, the environment pollution is avoided, the firmness is better, and the preparation efficiency and the integration level are higher; by disposing the second cut-off filter film on the first cut-off filter film and disposing the third cut-off filter film on the second cut-off filter film, the cut-off range of the interference band can be effectively widened. In addition, as the equivalent refractive indexes of the narrow-band filter film and the first cut-off filter film are different, the peak transmittance can be influenced by direct superposition, and the peak transmittance of the spectral imaging system can be effectively improved by arranging the transition layer between the narrow-band filter film and the first cut-off filter film. Compared with the external attaching cut-off filter film in the prior art, the spectrum imaging system provided by the invention integrates the first cut-off filter film and the narrow-band filter film in the spectrum imaging chip structure, so that the quantum efficiency and the spectrum transmittance are greatly improved; the second cut-off filter film is arranged on the first cut-off filter film, and the third cut-off filter film is arranged on the second cut-off filter film, so that the cut-off range of an interference wave band can be effectively widened; and a transition layer is arranged between the narrow-band filter film and the first cut-off filter film, so that the peak transmittance of the spectrum imaging chip structure is effectively improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. It is evident that the drawings in the following description are only some embodiments of the present invention and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 shows a schematic partial structure of a spectral imaging system (narrow-band filter shows only one FP cavity structure) provided according to a first embodiment of the present invention;

fig. 2 shows a schematic partial structure of a spectral imaging system (narrow-band filter shows only one FP cavity structure) provided according to a seventh embodiment of the present invention;

fig. 3 is a diagram showing a filtering effect of a spectral imaging chip structure without a cut-off filter film in a first comparative example provided according to a seventeenth embodiment of the present invention;

fig. 4 is a diagram showing a filtering effect of a spectral imaging chip structure in which a cut-off filter film determined by the film thickness adjustment coefficient determination method according to the present invention is added to a second comparative example provided according to a seventeenth embodiment of the present invention;

FIG. 5 is a diagram showing the filtering effect of a spectral imaging chip structure of a cut-off filter film randomly determined by adding a film thickness adjustment coefficient in a third comparative example provided in accordance with a seventeenth embodiment of the present invention;

FIG. 6 illustrates a schematic diagram of tuned filtering of a narrow band filter provided in accordance with a specific embodiment of the present invention;

FIG. 7 is a schematic diagram of tuned filtering of a narrow band filter in the presence of other band signal interference, provided in accordance with a specific embodiment of the present invention;

FIG. 8 shows a tuned filter schematic of a cut-off filter provided in accordance with a specific embodiment of the present invention;

FIG. 9 shows a tuning filter schematic of a narrow band filter plus cut-off filter provided in accordance with a specific embodiment of the present invention;

FIG. 10 shows a flow chart of the fabrication of a spectral imaging system provided in accordance with a twentieth embodiment of the present invention;

FIG. 11 shows a schematic structural diagram of a spectral imaging system provided according to a thirty-second embodiment of the present invention;

FIG. 12 shows a schematic structural diagram of a spectral imaging system provided according to a thirty-third embodiment of the present invention;

FIG. 13 shows a schematic structural diagram of a spectral imaging system provided according to a thirty-fifth embodiment of the present invention;

FIG. 14 shows a schematic structural diagram of a spectral imaging system provided according to a thirty-ninth embodiment of the present invention;

FIG. 15 shows a schematic structural diagram of a spectral imaging system provided according to a forty-third embodiment of the present invention;

fig. 16 shows spectral features of pre-and post-maturation drumsticks provided in accordance with a fifty-th embodiment of the present invention, wherein region 1 is the maturation drumstick and region 2 is the production drumstick;

FIG. 17 shows a schematic diagram of spectral leakage outside the useful spectral range of an FP cavity structure provided according to a fifty-th embodiment of the invention;

FIG. 18 shows a schematic diagram of spectral leakage outside the effective spectral range of an FP cavity structure provided according to a fifty-fifth embodiment of the invention;

FIG. 19 shows a schematic structural diagram of a spectral imaging system provided according to a sixteenth embodiment of the present invention;

FIG. 20 shows a schematic structural diagram of a spectral imaging system provided according to a sixty-ninth embodiment of the present invention; .

Wherein the above figures include the following reference numerals:

10. a pixel light sensing unit; 20. a narrow band filter film; 30. a first cut-off filter film; 60. a second cut-off filter film; 70. and a third stop filter film.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

As a first embodiment of the present invention, as shown in fig. 1, there is provided a spectral imaging system according to an embodiment of the present invention, the spectral imaging system including a pixel photosensitive unit 10 and a spectral imaging unit, the pixel photosensitive unit 10 for implementing image acquisition and data readout, the spectral imaging unit including a narrowband filter 20, a transition layer 40, a first cut-off filter 30, a second cut-off filter 60 and a third cut-off filter 70, the narrowband filter 20 being integrally deposited and grown on the pixel photosensitive unit 10, the narrowband filter 20 for implementing tunability at a center wavelength of a desired band, the transition layer 40 being integrally deposited and grown on the narrowband filter 20, the transition layer 40 being for transiting both the narrowband filter 20 and the first cut-off filter 30, the first cut-off filter 30 being integrally deposited on the narrowband filter 20, the second cut-off filter 60 being disposed on the first cut-off filter 30, the second cut-off filter 60 being for cutting off a second interference band, the second interference band being different from the first interference band; the third cut-off filter film 70 is disposed on the second cut-off filter film 60, and the third cut-off filter film 70 is used for cutting off a third interference band, which is different from the first interference band and the second interference band.

In the first embodiment of the invention, the spectral imaging system integrally deposits and grows the narrow-band filter film on the pixel photosensitive unit, the transition layer integrally deposits and grows the narrow-band filter film, the first cut-off filter film integrally deposits and grows on the transition layer, no gap exists among the first cut-off filter film, the transition layer, the narrow-band filter film and the pixel photosensitive unit, the spectral transmittance is high, the energy loss is reduced, the spectral imaging system is integrally formed by a one-step preparation process, and the spectral imaging system is free from external environment pollution, has better firmness, and higher preparation efficiency and integration level; by disposing the second cut-off filter film on the first cut-off filter film and disposing the third cut-off filter film on the second cut-off filter film, the cut-off range of the interference band can be effectively widened. In addition, as the equivalent refractive indexes of the narrow-band filter film and the first cut-off filter film are different, the peak transmittance can be influenced by direct superposition, and the peak transmittance of the spectral imaging system can be effectively improved by arranging the transition layer between the narrow-band filter film and the first cut-off filter film. Compared with the external attaching cut-off filter film in the prior art, the spectrum imaging system provided by the invention integrates the first cut-off filter film and the narrow-band filter film in the spectrum imaging chip structure, so that the quantum efficiency and the spectrum transmittance are greatly improved; the second cut-off filter film is arranged on the first cut-off filter film, and the third cut-off filter film is arranged on the second cut-off filter film, so that the cut-off range of an interference wave band can be effectively widened; and a transition layer is arranged between the narrow-band filter film and the first cut-off filter film, so that the peak transmittance of the spectrum imaging system is effectively improved.

As a second embodiment of the present invention, there is provided a spectral imaging system in which the arrangement of the second cutoff filter film and the third cutoff filter film is defined on the basis of the first embodiment. In this embodiment, the second cut filter film 60 is integrally deposited and grown on the first cut filter film 30, and the third cut filter film 70 is integrally deposited and grown on the second cut filter film 60. In this embodiment, the second cut-off filter film 60 is integrally deposited and grown on the first cut-off filter film 30, the third cut-off filter film 70 is integrally deposited and grown on the second cut-off filter film 60, and there is no gap between the third cut-off filter film, the second cut-off filter film, the first cut-off filter film, the transition layer, the narrow-band filter film and the pixel photosensitive unit, so that the spectral transmittance is high, the energy loss is reduced, the one-step preparation process is integrally formed, the external environment pollution is avoided, the firmness is better, and the preparation efficiency and the integration level are higher.

As a third embodiment of the present invention, there is provided a spectral imaging system in which the arrangement of the second cutoff filter film and the third cutoff filter film is defined on the basis of the first embodiment. In this embodiment, the second cut filter film 60 is integrally deposited and grown on the first cut filter film 30, and the third cut filter film 70 is adhesively disposed on the second cut filter film 60. According to the embodiment, the second cut-off filter film 60 is integrally deposited and grown on the first cut-off filter film 30, no gap exists among the second cut-off filter film, the first cut-off filter film, the transition layer, the narrow-band filter film and the pixel photosensitive unit, the spectral transmittance is high, the energy loss is reduced, the one-step preparation process is integrally formed, the external environment pollution is avoided, the firmness is better, and the preparation efficiency and the integration level are higher. By disposing the third cut-off filter film 70 on the second cut-off filter film 60 by sticking, the cut-off range of the interference band can be effectively widened.

As a fourth embodiment of the present invention, there is provided a spectral imaging system in which the arrangement of the second cutoff filter film and the third cutoff filter film is defined on the basis of the first embodiment. In this embodiment, the second cut filter film 60 is stuck on the first cut filter film 30, and the third cut filter film 70 is stuck on the second cut filter film 60. In the present embodiment, the second cut-off filter film 60 is attached to the first cut-off filter film 30, and the third cut-off filter film 70 is attached to the second cut-off filter film 60, so that the cut-off range of the interference band can be effectively widened.

As a fifth embodiment of the present invention, there is provided a spectral imaging system further defined by a film system structure of a spectral imaging unit on the basis of the first to fourth embodiments, in which the film system structure of the spectral imaging chip structure is configured as sub|h (LH) ≡s ₁ 2nL(HL)^S ₁ HLn ₁ (W1)^S ₂ n ₂ (W2)^S ₃ n ₃ (W3)^S ₄ |Air，H(LH)^S ₁ 2nL(HL)^S ₁ H is the film structure of the narrow band filter 20, L is the film structure of the transition layer 40, W1, W2 and W3 each comprise a high refractive index material and a low refractive index material, n ₁ (W1)^S ₂ Is a film system structure of the first cut-off filter film 30, n ₂ (W2)^S ₃ Is the film structure of the second cut-off filter film 60, n ₃ (W3)^S ₄ Is a film structure of the third stop filter film 70, H is a high refractive index material, L is a low refractive index material, S ₁ 、S ₂ 、S ₃ And S is ₄ For the number of overlapping times, n is the film thickness adjustment coefficient of the narrow-band filter film, n ₁ For the film thickness adjustment coefficient, n, of the first cut-off filter film 30 ₂ For the film thickness adjustment coefficient, n, of the second cut-off filter film 60 ₃ The film thickness adjustment coefficient for the third stop filter film 70. In the fifth embodiment of the present invention, by configuring a specific mode structure of an optical imaging system, tunability of center filtering in a desired band and prevention of stray light interference can be achieved. In the present invention, the film thickness adjustment coefficient n of the cut-off filter film ₁ 、n ₂ And n ₃ There are two determination methods, the first is obtained by software simulation, in which various filter curves can be simulated by software, and the most preferred film thickness adjustment coefficients are determined by the performance differences of tuned filter curves obtained by different parameters. The second way is by determining the band to be cut off of the cut-off filter; calculating and obtaining the central wavelength of the spectrum segment to be cut according to the first boundary threshold value and the second boundary threshold value of the spectrum segment to be cut; the film thickness adjusting coefficient of the cut-off filter film is determined according to the center wavelength of the spectrum to be cut-off and the center wavelength of the narrow-band filter film, and the film thickness adjusting coefficient is obtained in a numerical calculation mode, so that the calculation mode is simple, and the effective cut-off of a specific wave band can be realized. In the actual application process, the selection can be performed according to actual needs.

As a sixth embodiment of the present invention, there is provided a spectral imaging system further defined in terms of a film system structure of a spectral imaging unit on the basis of the above-described embodiments. In the spectral imaging unit, S ₁ ＝5-7，S ₂ ,S ₃ ,S ₄ ＝8-13，n ₁ ,n ₂ ,n ₃ =0.5-2.5. Wherein Sub is a substrate Si, air is Air, H represents a high refractive index material Ta ₂ O ₅ 、Ti ₃ O ₅ 、TiO ₂ 、Si ₃ N ₄ 、Nb ₂ O ₅ One of them; l represents a low refractive index material SiO ₂ 、MgF ₂ Al and ₂ O ₃ one or a mixture thereof.

As a seventh embodiment of the present invention, as shown in fig. 2, there is provided a spectral imaging system in which the matching layer is defined on the basis of the first to fourth embodiments. In this embodiment, the spectral imaging unit further includes a matching layer 50, the matching layer 50 is integrally deposited on the pixel photosensitive unit 10, and the matching layer 50 is used for transiting the optical admittance between the photosensitive unit 10 and the narrow-band filter film 20, the transition layer 40, the first cut-off filter film 30, the second cut-off filter film 60 and the third cut-off filter film 70 to improve the central wavelength peak transmittance; the narrow band filter 20 is integrally deposited on the matching layer 50. In the embodiment, in the growth process of the narrow-band filter film, the refractive index difference between the film layer material and the pixel photosensitive unit material of the image sensor is large, the refractive index mismatch is caused by direct growth, the central wavelength peak transmittance is reduced, the quantum efficiency of the spectrum imaging system is low, and the imaging effect is affected, so that the problems of the refractive index mismatch and the central wavelength peak transmittance reduction can be effectively overcome, and the central wavelength peak transmittance of the spectrum imaging system is effectively improved by arranging the matching layer between the pixel photosensitive unit and the narrow-band filter film.

As an eighth embodiment of the present invention, there is provided a spectral imaging system further defined by a film system structure of a spectral imaging unit based on the seventh embodiment, wherein the film system structure of the spectral imaging unit is configured as sub|hlh (LH) ≡s ₁ 2nL(HL)^S ₁ HLn ₁ (W1)^S ₂ n ₂ (W2)^S ₃ n ₃ (W3)^S ₄ I Air, HL is the film structure of the matching layer 50, H (LH) ≡S ₁ 2nL(HL)^S ₁ H is the film structure of the narrow band filter 20, L is the film structure of the transition layer 40, n ₁ (W1)^S ₂ Is a film system structure of the first cut-off filter film 30, n ₂ (W2)^S ₃ Is the film structure of the second cut-off filter film 60, n ₃ (W3)^S ₄ For the third stop filter film 70Wherein W1, W2 and W3 each comprise a high refractive index material and a low refractive index material, H is a high refractive index material, L is a low refractive index material, S ₁ 、S ₂ 、S ₃ And S is ₄ For the number of times of lamination, n is the film thickness adjustment coefficient of the narrow band filter film 20, n ₁ For the film thickness adjustment coefficient, n, of the first cut-off filter film 30 ₂ For the second cut-off filter 60 film thickness adjustment factor, n ₃ The film thickness adjustment coefficient for the third stop filter film 70. In a second embodiment of the present invention, by configuring a specific film system structure of an optical imaging system, tunable filtering at the center of a desired band and prevention of stray light interference can be achieved. In the present invention, the film thickness adjustment coefficient n of the cut-off filter film ₁ 、n ₂ And n ₃ There are two determination methods, the first is obtained by software simulation, in which various filter curves can be simulated by software, and the most preferred film thickness adjustment coefficients are determined by the performance differences of tuned filter curves obtained by different parameters. The second way is by determining the band to be cut off of the cut-off filter; calculating and obtaining the central wavelength of the spectrum segment to be cut according to the first boundary threshold value and the second boundary threshold value of the spectrum segment to be cut; the film thickness adjusting coefficient of the cut-off filter film is determined according to the center wavelength of the spectrum to be cut-off and the center wavelength of the narrow-band filter film, and the film thickness adjusting coefficient is obtained in a numerical calculation mode, so that the calculation mode is simple, and the effective cut-off of a specific wave band can be realized. In the actual application process, the selection can be performed according to actual needs.

As a ninth embodiment of the present invention, there is provided a spectral imaging system, which is further defined by the cutoff filter film on the basis of the above-described embodiments. In the embodiment, the first cut-off filter film is integrally deposited and grown on the narrow-band filter film by adopting a semiconductor process, and the first cut-off filter film is made of a material compatible with the semiconductor process, so that the spectral transmittance is further improved, and the energy loss is reduced. In the film system structure of the first cut filter film 30, W1 includes (0.5LH0.5L) or (0.5HL0.5H). The second cut filter film 60 is adhered or integrally deposited on the first cut filter film 30, and W2 includes (0.5LH0.5L) or (0.5HL0.5H) in the film system structure of the second cut filter film 60. The third stop filter film 70 is adhered or integrally deposited on the second stop filter film 60, and W3 includes (0.5LH0.5L) or (0.5HL0.5H) in the film system structure of the third stop filter film 70.

As a tenth embodiment of the present invention, there is provided a spectral imaging system, which is further defined by the cutoff filter film on the basis of the above-described embodiments. The first, second and third cut-

off filter films

30, 60 and 70 are each prepared by alternately depositing a high refractive index material and a low refractive index material. The high refractive index materials of the first, second and third

cutoff filter films

30, 60 and 70 each include Ta ₂ O ₅ 、Ti ₃ O ₅ 、TiO ₂ 、Si ₃ N ₄ Or Nb (Nb) ₂ O ₅ The low refractive index materials of the first, second and third

cutoff filter films

30, 60 and 70 each include SiO ₂ 、MgF ₂ And Al ₂ O ₃ At least one of them. By limiting the cut-off filter film, the quantum efficiency and spectral transmittance can be greatly improved.

As an eleventh embodiment of the present invention, there is provided a spectral imaging chip structure, which is further defined on the basis of the foregoing embodiments as to the structure of the narrow-band filter film. In this embodiment, the narrow-band filter film 20 includes a plurality of FP cavity structures, each of the FP cavity structures is formed by a semiconductor process at one time, any FP cavity structure includes a first mirror, a light-transmitting layer, and a second mirror that are sequentially stacked from bottom to top, the FP cavity structures are distributed in a mosaic shape, heights of the light-transmitting layers of the FP cavity structures along any one column of the narrow-band filter film 20 are different, and heights of the light-transmitting layers of the FP cavity structures along any one row of the narrow-band filter film 20 are different. Alternatively, other types of structures may be adopted for the narrow-band filter film, specifically, the FP cavity structures are distributed in a line scan manner, the heights of the light-transmitting layers of the FP cavity structures along any one column of the narrow-band filter film 20 are the same, and the heights of the light-transmitting layers of the FP cavity structures along any one row of the narrow-band filter film 20 are different. In the present invention, the narrow band filter may take various forms without limitation.

In the eleventh embodiment of the present invention, by arranging the structure of the narrow-band filter film, the structural complexity of the chip structure can be effectively reduced, the structural volume can be reduced, and the cost can be reduced. The narrow-band filter film comprises a plurality of FP cavity structures, the pixel photosensitive unit comprises a plurality of pixel photosensitive parts, the plurality of FP cavity structures are arranged in one-to-one correspondence with the plurality of pixel photosensitive parts, any FP cavity structure comprises a first reflecting mirror, a light passing layer and a second reflecting mirror which are sequentially overlapped from bottom to top, the plurality of FP cavity structures are distributed in a mosaic mode or line sweeping mode, the plurality of FP cavity structures are formed in one step by adopting a semiconductor technology, and the first reflecting mirror, the light passing layer, the second reflecting mirror and the pixel photosensitive parts are made of materials compatible with the semiconductor technology and are strictly aligned in the longitudinal direction without later-stage lamination. In the mode, the traditional light splitting system is directly processed on the pixel photosensitive unit of the photoelectric sensor by means of advanced semiconductor (CMOS) process technology, stray light is reduced due to tight connection, photon utilization rate is improved, and therefore speed can reach hundred frames per second, and a spectrum video function is realized; the volume and the weight are not different from those of a common RGB chip, and an imaging system with the size of a finger is realized; CMOS technology provides an unparalleled level of integration for the spectral imaging chip structure, and can be connected with any circuit with high integration, such as embedded in a mobile phone.

As a twelfth embodiment of the present invention, there is provided a spectral imaging system, the integral growth cutoff filter film further defined on the basis of the foregoing embodiment. In this embodiment, the first mirror is an upper mirror, the second mirror is a lower mirror, and the upper mirror is made of multiple layers of high-reflectivity materials and multiple layers of low-reflectivity materials alternately to form a bragg mirror, which are overlapped with each other for multiple times, and the reflectivity reaches over 99% as a cavity mirror of an FP cavity structure. The lower reflector has the same structure and material as the upper reflector, and is positioned between the light transmitting layer and the pixel photosensitive part, and has high reflection effect.

As a thirteenth embodiment of the present invention, there is provided a spectral imaging system in which the film thickness adjustment coefficient of any one of the cut-off filter films is further defined on the basis of the above-described embodiments. In this embodiment, the film thickness adjustment coefficient may be obtained according to the following steps: determining a spectrum section to be cut off of any cut-off filter film; calculating and obtaining the central wavelength of the spectrum segment to be cut according to the first boundary threshold value and the second boundary threshold value of the spectrum segment to be cut; and determining the film thickness adjustment coefficient of any cut-off filter film according to the center wavelength of the to-be-cut-off spectrum and the center wavelength of the narrow-band filter film.

In the fourteenth embodiment of the present invention, by optimally designing any one of the cutoff filter films, that is, by designing the film thickness adjustment coefficient of any one of the cutoff filter films, specifically, calculating and obtaining the center wavelength of the to-be-cut-off spectrum according to the first boundary threshold and the second boundary threshold of the to-be-cut-off spectrum, determining the film thickness adjustment coefficient of the cutoff filter film by the center wavelength of the to-be-cut-off spectrum and the center wavelength of the narrow band filter film, thus, when the cutoff filter film with the film thickness adjustment coefficient is integrally deposited on the narrow band filter film, light leakage outside the free spectrum range can be greatly suppressed, cut-off of the interference band is completed, the side mode suppression ratio of the spectral filter is greatly improved, and the spectral imaging performance of the spectral imaging chip structure is improved.

As a fifteenth embodiment of the present invention, there is provided a spectral imaging system in which the center wavelength of a spectrum to be cut-off is defined on the basis of the above-described embodiments. In this embodiment, the center wavelength of the spectral band to be cut-off may be based on

To obtain; alternatively, the center wavelength of the spectral band to be cut-off may be determined according to +.>

Is obtained by, wherein lambda ₀ For the middle of the spectrum to be cut off Heart wavelength, lambda ₁ For a first boundary threshold, lambda, of the spectral band to be cut-off ₂ Is a second boundary threshold for the portion of spectrum to be cut off. The above are two methods for obtaining the center wavelength of the spectrum to be cut off, wherein +.>

The center wavelength of the spectrum to be cut off is obtained, the calculation accuracy is higher, and the suppression of light leakage outside the free spectrum range (compared with the formula +.>

The center wavelength of the band to be cut off is obtained).

As a sixteenth embodiment of the present invention, there is provided a spectral imaging system in which the film thickness adjustment coefficient of any one of the cut-off filter films is defined on the basis of the above-described embodiments. In this embodiment, the film thickness adjustment coefficient n of any one of the cut-off filter films can be determined according to

Is obtained, wherein lambda is the center wavelength of the narrow-band filter film, n=n ₁ 、n ₂ Or n ₃ . By adopting the method to determine the film thickness adjustment coefficient of the cut-off filter film, light leakage outside the free spectrum range can be greatly inhibited, cut-off of interference wave bands is completed, the side mode inhibition ratio of spectrum filtering is greatly improved, and the spectrum imaging performance of the spectrum imaging chip structure is improved.

As a seventeenth embodiment of the present invention, there is provided a spectral imaging system which exemplifies the effect of the film thickness adjustment coefficient determination method on suppressing light leakage on the basis of the foregoing embodiments. Taking the lambda as the center wavelength of 600nm as an example, the first comparative example is that a cut-off filter film is not added, and the filtering effect is obtained as shown in fig. 3, it can be seen that narrow-band filtering is realized only in the range of 530nm to 696nm, and the light leakage phenomena are very serious in the spectral ranges of 400nm to 520nm and 700nm to 1000nm, which is very serious for responding to the SI-based detector in the spectral range of 400nm to 1000nm, and the two spectral ranges need to be suppressed.

In the second comparative example of the seventeenth embodiment, according to the light leakage spectrum of 400nm to 520nm and 700nm to 1000nm, it is designed that a first cut-off filter film is integrally deposited on the narrow-band filter film, a second cut-off filter film is attached to the first cut-off filter film, and a third cut-off filter film is attached to the second cut-off filter film, wherein the first cut-off filter film is used for suppressing light leakage in the range of 400nm to 520nm, and the center wavelength is

Determining the center wavelength to be 452nm; corresponding film thickness adjustment coefficient alpha ₁ 452nm/600nm = 0.75; similarly, the second cut-off filter film suppresses light leakage in the range of 700nm to 780nm with a center wavelength of +.>

Determining that the center wavelength is 738nm; corresponding film thickness adjustment coefficient alpha ₂ 738nm/600 nm=1.23; the third cut-off filter film suppresses light leakage in the range of 780-1000 nm with a center wavelength of

Determining the center wavelength to be 876nm; corresponding film thickness adjustment coefficient alpha ₃ 876nm/600 nm=1.46.

In the third comparative example, the difference from the second comparative example is only for the coefficient α ₁ 、α ₂ And alpha ₃ Taking 0.7, 1.1 and 1.4 respectively, and randomly acquiring the coefficients, namely determining the film thickness adjustment coefficients without the method according to the embodiment of the invention.

Fig. 4 is a diagram showing a filtering effect of the spectral imaging system provided by the second comparative example, and fig. 5 is a diagram showing a filtering effect of the spectral imaging system provided by the third comparative example, where it can be seen that the light leakage outside the free spectral range can be greatly suppressed by determining the film thickness adjustment coefficient by using the embodiment of the present invention. On the contrary, if the film thickness adjustment coefficient is not determined according to the method of the embodiment of the invention, although the cut-off filter film is added and the coefficient difference is small, the light leakage outside the free spectrum range is difficult to be well inhibited, and even the light leakage problem cannot be solved.

As an eighteenth embodiment of the present invention, there is provided a spectral imaging system incorporating a plurality of spectral imaging units on the basis of the foregoing embodiments. In this embodiment, the spectral imaging system includes a plurality of spectral imaging units, and the pixel photosensitive unit 10 is divided into a plurality of pixel areas in the spectral dimension direction; the narrow band filter films 20 of the plurality of spectral imaging units are integrally deposited and grown on the plurality of pixel areas respectively in one-to-one correspondence. In this embodiment, the pixel photosensitive unit may be a CMOS pixel photosensitive unit. For example, the pixels of the pixel photosensitive unit are m×n, m and n may be equal or different, and the pixel photosensitive unit includes m pixels along the spectral dimension direction, so that the pixel photosensitive unit is split into a corresponding number of pixel areas along the pixel direction according to the number of required spectral imaging units. In this embodiment, the spectrum range required to be covered by each spectrum imaging unit may be designed according to the narrowband filtering spectrum range (for example, the spectrum range 490-900 nm for implementing coverage of visible light) required to be satisfied by the chip structure. Therefore, according to the embodiment of the invention, a plurality of spectrum imaging units are integrally deposited and grown on the same pixel photosensitive unit (only one spectrum imaging unit is arranged on one pixel photosensitive unit in the prior art), the spectrum imaging units cover different spectrum ranges, the limitation of a material refractive index difference on a free spectrum range is broken through, the free spectrum range of narrow-band filtering of a single-chip image sensor is widened, and a micro spectrum imaging system with high extinction ratio and narrow-band spectral characteristics in a visible light spectrum range (490-900 nm) is obtained.

In addition, as a unique advantage of the embodiment, the spectrum imaging system of the embodiment of the invention is a single-chip spectrum imaging system with wide free spectrum and wide range, compared with the scheme that a single structural chip (only one spectrum imaging unit is arranged on one pixel photosensitive unit in the prior art) is spliced (a plurality of chip structures are spliced) to realize the broadening of the spectrum range, the spectrum imaging system of the invention can realize the broadening coverage of the free spectrum by depositing a plurality of spectrum imaging units on a photosensitive area without changing a readout circuit of a subsequent image sensor; the method does not need to develop a post-development readout high-speed splicing algorithm, does not need a high-speed FPGA (field programmable gate array) board-level hardware system, has large advantages in terms of volume, weight and cost, and is a real single chip SoC (System on Chip). In addition, if spectrum broadening is realized by splicing the chips with separate structures, the package SIP (System in a Package) is systemized, and a plurality of image sensors are needed, and meanwhile, an FPGA high-speed multi-path parallel reading system is also needed, so that the cost and the volume of the system cannot be compared with those of the spectrum imaging system provided by the embodiment of the invention.

As a nineteenth embodiment of the present invention, there is provided a spectral imaging system in which the structure of a spectral imaging unit is defined on the basis of the foregoing embodiments. In this embodiment, the narrow-band filter film 20 of any spectral imaging unit includes a plurality of FP cavity structures, each of the FP cavity structures is formed by a semiconductor process in one step, each of the FP cavity structures includes a first mirror, a light-transmitting layer, and a second mirror sequentially stacked from bottom to top, the plurality of FP cavity structures are distributed in a line scan manner, the heights of the light-transmitting layers of the plurality of FP cavity structures along the spatial dimension direction of the narrow-band filter film are the same, and the heights of the light-transmitting layers of the plurality of FP cavity structures along the spectral dimension direction of the narrow-band filter film are different.

As a twentieth embodiment of the present invention, there is provided a spectral imaging system, as shown in fig. 10, which is based on the foregoing embodiment, and has two spectral imaging units. In this embodiment, the spectral imaging system includes a first spectral imaging unit and a second spectral imaging unit, and the pixel photosensitive unit 10 is divided into a first pixel region and a second pixel region in the spectral dimension direction; the narrow band filter film 20 of the first spectral imaging unit is integrally deposited and grown on the first pixel region, and the narrow band filter film 20 of the second spectral imaging unit is integrally deposited and grown on the second pixel region. The spectral imaging system in this embodiment is capable of narrowband filtering in the 490nm to 1000nm spectral range.

As a twenty-first embodiment of the present invention, there is provided a spectral imaging system in which, in order to ensure that narrow-band filtering of a spectral range of 490nm to 1000nm can be achieved using two spectral imaging units, a first spectral imaging unit covers a spectral range of 490nm to 620nm and a second spectral imaging unit covers a spectral range of 650nm to 1000nm.

As a twenty-second embodiment of the present invention, there is provided a spectral imaging system in which the narrow-band filter film of the first spectral imaging unit is defined on the basis of the twenty-first embodiment. In this embodiment, the narrow-band filter 20 of the first spectral imaging unit includes a plurality of FP cavity structures, each of which is formed by a semiconductor process, and any FP cavity structure includes a first mirror, a first light-transmitting layer, and a second mirror sequentially stacked from bottom to top, the FP cavity structures are distributed in a line scan, the first mirror is alternately made of a plurality of layers of high-reflectivity materials and a plurality of layers of low-reflectivity materials, the second mirror has the same structure as the first mirror, and the first light-transmitting layer is formed by deposition growth of low-reflectivity materials, wherein the high-reflectivity materials include SI ₃ N ₄ The low reflectivity material comprises SIO ₂ 。

In a twenty-second embodiment, the first mirror, the second mirror and the first light-transmitting layer of the first spectral imaging unit form a typical fabry-perot cavity, the pixel light-sensing part of a single pixel of the pixel light-sensing unit is arranged below the first mirror, the first mirror (i.e. the lower mirror) and the pixel light-sensing part are manufactured by adopting an integrated manufacturing method, no gap exists, the pixel light-sensing part is followed by a complete electrical readout circuit, and the light-transmitting layer of the fabry-perot cavity realizes tuning of imaging light-sensing wavelength through a stepped pattern of a graded cavity. Wherein the second mirror (i.e., the upper mirror) employs a multilayer high reflectivity (SI ₃ N ₄ ) Substances and multilayer low reflectivity (SIO) ₂ ) The materials are alternately prepared to form Bragg reflectors which are mutually overlapped for a plurality of times, the reflectivity can reach more than 99 percent, and the Bragg reflectors can be used as the cavity mirrors of FP cavities, the stacked structure can be (HL) ≡nH, and H is SI ₃ N ₄ Layer film, L is SIO ₂ A film layer; n is the number of overlapping times. The lower reflector has the same structure and material as the upper reflector and is positioned atThe light transmitting layer and the photosensitive pixels have high anti-reflection effect. The light-transmitting layer is composed of a low refractive index (SIO) ₂ ) The material is deposited and grown, the deposition structure is mL, m is a coefficient, and a step pattern structure of the graded cavity is formed through a semiconductor process, and the step interface is coincident with the pixel boundary of the pixel photosensitive unit. Namely, the first light-splitting structure is designed in the mode, so that the first light-splitting structure can cover the spectrum range of 490-620 nm.

As a twenty-third embodiment of the present invention, there is provided a spectral imaging system in which the narrow-band filter film of the second spectral imaging unit is defined on the basis of the twenty-first embodiment. In this embodiment, the narrow-band filter 20 of the second spectral imaging unit includes a plurality of FP cavity structures, each of the FP cavity structures is formed by one-step formation using a semiconductor process, any FP cavity structure includes a third mirror, a second light-transmitting layer, and a fourth mirror sequentially stacked from bottom to top, a plurality of FP cavity structures are distributed in a line scan manner, the third mirror is alternately prepared from a plurality of layers of high-reflectivity materials and a plurality of layers of low-reflectivity materials, the fourth mirror has the same structure as the third mirror, the second light-transmitting layer is formed by depositing and growing a low-reflectivity material, wherein the high-reflectivity material includes α -SI, and the low-reflectivity material includes SIO ₂ 。

In a twenty-third embodiment, the upper mirror (i.e., the third mirror), the lower mirror (i.e., the fourth mirror) and the light-transmitting layer of the second spectral imaging unit form a typical fabry-perot cavity, a pixel photosensitive part of a single pixel of the pixel photosensitive unit is arranged below the lower mirror, the lower mirror and the pixel photosensitive part adopt an integrated preparation method, no gap exists, the pixel photosensitive part is followed by a complete electrical readout circuit, and the light-transmitting layer of the fabry-perot cavity realizes tuning of imaging photosensitive wavelength through a stepped pattern of a tapered cavity. Wherein the upper mirror employs a multilayer high reflectance (alpha-SI) material and a multilayer low reflectance (SIO) ₂ ) The materials are alternately prepared to form a Bragg reflector, the Bragg reflector is overlapped for a plurality of times, the reflectivity can reach more than 99 percent, the Bragg reflector is used as a cavity mirror of an FP cavity, the stacked structure is (HL)/(nH), H is an alpha-SI layer film, and L is SIO ₂ Film layer, n is overlapping times. The lower reflecting mirror has the same structure and material as the upper reflecting layer, and is positioned between the light transmitting layer and the photosensitive pixels, and has high reflection effect. The light-transmitting layer is composed of a low refractive index (SIO) ₂ ) The material is deposited and grown, the deposition structure is mL, m is a coefficient, and a step pattern structure of the graded cavity is formed through a semiconductor process, and the step interface is coincident with the pixel boundary of the pixel photosensitive unit. Namely, the second spectrum imaging unit is designed in the mode, so that the second spectrum imaging unit can cover the spectrum range of 650 nm-1000 nm.

It can be seen that, in the twentieth to twenty-third embodiments, only two spectroscopic structures (the first spectroscopic imaging unit and the second spectroscopic imaging unit) with different structures are deposited on the pixel photosensitive unit to achieve narrow-band filtering in the 490 nm-1000 nm spectral range, while in the prior art, the materials with high refractive index compatible with the CMOS process are less, and mainly the materials are α -SI, tiO2, SI ₃ N ₄ Ta and the like ₂ O ₅ And the like, the refractive index of alpha-SI is more than 3.5 in the visible light range, but the refractive index of other materials is only about 2; while the low refractive index material is essentially SIO ₂ Refractive index is about 1.5; since the free spectral range of the Bragg mirror is determined by the refractive index difference between the high refractive index material and the low refractive index material grown in a stacked manner, the larger the refractive index difference, the wider the free spectral range; alpha-SI refractive index and SIO ₂ The refractive index difference satisfies the coverage of the visible light/near infrared spectrum, but the extinction coefficient of alpha-SI is very large before 600nm, and the light is basically not transmitted; the free spectrum range of the Bragg mirror is narrower due to the smaller refractive index difference of other high refractive index materials, the free spectrum range is only about 150nm, the coverage of the visible spectrum range by a structural design cannot be met, and the SIO is adopted at 490-620 nm in the embodiment of the invention ₂ /SI ₃ N ₄ As a Bragg mirror stacking material, alpha-SI/SIO is adopted at the wave band of 650 nm-1000 nm ₂ As a stacking material of the Bragg mirror, two completely different graded cavity structures are made on one chip, and a spectrum imaging system with a spectrum coverage range of 490-1000 nm is obtained.

As a twenty-fourth embodiment of the present invention, there is provided a spectral imaging system having three spectral imaging units, which is based on the foregoing embodiments. In this embodiment, the spectral imaging system includes a third spectral imaging unit, a fourth spectral imaging unit, and a fifth spectral imaging unit, and the pixel photosensitive unit 10 is divided into a third pixel region, a fourth pixel region, and a fifth pixel region in the spectral dimension direction; the narrow-band filter film 20 of the third spectral imaging unit is integrally deposited and grown on the third pixel region, the narrow-band filter film 20 of the fourth spectral imaging unit is integrally deposited and grown on the fourth pixel region, and the narrow-band filter film 20 of the fifth spectral imaging unit is integrally deposited and grown on the fifth pixel region. The three spectral imaging units in this embodiment are capable of jointly achieving narrow band filtering in the 490nm to 1000nm spectral range.

As a twenty-fifth embodiment of the present invention, there is provided a spectral imaging system in which the spectral ranges of the respective spectral imaging units are defined on the basis of the twenty-fourth embodiment. In this embodiment, the spectrum range covered by the third spectrum imaging unit is 490nm to 620nm, the spectrum range covered by the fourth spectrum imaging unit is 640nm to 800nm, and the spectrum range covered by the fifth spectrum imaging unit is 800nm to 1000nm.

As a twenty-sixth embodiment of the present invention, there is provided a spectral imaging system defined by the twenty-fifth embodiment, wherein the narrow band filter of the spectral imaging unit is a filter. In this embodiment, the narrow-band filter film 20 of any spectral imaging unit includes a plurality of FP cavity structures, each of which is formed by a semiconductor process, and each of which includes a first reflecting mirror, a light-transmitting layer, and a second reflecting mirror sequentially stacked from bottom to top, the FP cavity structures are distributed in a line scan, the first reflecting mirror is alternately made of a plurality of layers of high-reflectivity materials and a plurality of layers of low-reflectivity materials, the second reflecting mirror has the same structure as the first reflecting mirror, and the first light-transmitting layer is formed by deposition growth of a low-reflectivity material, wherein the high-reflectivity material includes SI ₃ N ₄ The low reflectivity material comprises SIO ₂ 。

In the twenty-sixth embodiment, in order to achieve narrow-band filtering in the 490nm to 1000nm spectral range, when the spectral imaging system includes three spectral imaging units, the upper and lower reflectors of each spectral imaging unit need only employ a high-reflectivity material including SI ₃ N ₄ Low reflectivity materials including SIO ₂ The preparation can achieve the desired spectral range. That is, since the high refractive index material compatible with CMOS process is less, the material is mainly prepared by alpha-SI, tiO ₂ ,SI ₃ N ₄ Ta and the like ₂ O ₅ And the refractive index of alpha-SI is more than 3.5 in the visible light range, the refractive index of other materials is only about 2, and when the spectrum imaging unit exceeds three types, the materials with high refractive index of about 2 are adopted, namely when the spectrum imaging unit exceeds three types, the materials can be prepared by adopting the same materials.

As a twenty-seventh embodiment of the present invention, there is provided a spectral imaging system, which includes, on the basis of the foregoing embodiments, a plurality of spectral imaging units and a plurality of color filter groups, the narrow-band filter films 20 of the plurality of spectral imaging units being sequentially deposited and grown on the pixel photosensitive unit 10 in an integrated manner at intervals, the plurality of color filter groups being sequentially deposited and grown on the pixel photosensitive unit 10 in an integrated manner at intervals, one of the color filter groups being disposed between any two adjacent spectral imaging units, the color filter groups including a plurality of color filters, the color filter groups constituting a bayer array.

In the twenty-seventh embodiment, aiming at the situation that the camera such as a mobile phone has color distortion in the shooting process, the shooting color restoration effect of the camera of the mobile phone is improved by adding a spectrum imaging mode on the traditional color filter group. According to the invention, by combining the arrangement mode of the line scanning type spectrum imaging chip, on the basis of the arrangement of the color filter groups, a plurality of line scanning type spectrum imaging units are periodically arranged in a sparse distribution mode, so that a sparse distribution line scanning type spectrum imaging system is formed, on the basis of the imaging of the traditional color filter groups, narrowband spectrum imaging information of a plurality of spectral bands is introduced at the same time, the photographing color reduction effect of a mobile phone can be effectively improved in the field of mobile phone color correction, and the photographing color is more similar to the color observed by naked eyes.

As a twenty-eighth embodiment of the present invention, there is provided a spectral imaging system in which, on the basis of the foregoing embodiments, a line of spectral imaging units is distributed on a pixel photosensitive unit at a fixed pixel line spacing, and color filter groups are periodically arranged between the two lines of spectral imaging units. The structure has simple preparation process and is convenient for the uniform acquisition and analysis of spectrum information.

As a twenty-ninth embodiment of the present invention, there is provided a spectral imaging system which defines a line spacing between any two adjacent spectral imaging units on the basis of the foregoing embodiments. In this embodiment, the line spacing between any two adjacent spectral imaging units is greater than or equal to 4. Since a typical bayer array is a 4×4 array, which is composed of 8 green, 4 blue and 4 red pixels, 9 operations are performed in a 2×2 matrix when converting a gray pattern into a color picture, and finally a color pattern is generated. Therefore, the fixed line spacing between any two adjacent spectrum imaging units in the invention is generally not less than 4, which is convenient for image analysis and calculation.

As a thirty-first embodiment of the present invention, there is provided a spectral imaging system defined by the color filter set on the basis of the foregoing embodiments. In this embodiment, any one of the color filter groups includes an RGGB color filter structure, a RYYB color filter structure, or an RGWB color filter structure.

As a thirty-first embodiment of the present invention, there is provided a spectral imaging system, in which, on the basis of the foregoing embodiments, a spectral imaging chip structure employs a CMOS pixel light-sensing unit, and a CMOS-compatible spectral imaging unit, a bayer array, are integrally grown on the CMOS pixel light-sensing unit. The spectrum imaging unit and the Bayer array are integrally grown on the pixel photosensitive unit, so that the crosstalk between pixels is reduced, and the volume of a light splitting layer is reduced.

As a thirty-second embodiment of the present invention, conventional image sensing is employedFor example, the sparse distribution line scanning spectrum imaging system includes a pixel photosensitive unit, as shown in fig. 11, a line of spectrum imaging units is distributed every several lines of pixels on the whole pixel photosensitive unit, wherein λ ₁ ...λ _n For the spectrum filtering structure, any spectrum imaging unit corresponds to a central wavelength, and the central wavelengths of a plurality of spectrum imaging units are sequentially graded. The common RGGB color filter array is arranged between the spectrum filtering structures. The RGGB structure is periodically arranged and distributed among the spectrum imaging units. The spectrum imaging unit of each row is a spectrum imaging structure with one wavelength and n spectrum wavelengths distributed on the whole pixel array surface. The number of n depends on the application scene of the chip, and the customized design can be carried out, and the value range is more than 2 and less than the total number of rows of the whole pixel array.

As a thirty-third embodiment of the present invention, taking a sparse distribution line scanning spectrum imaging system of four spectral bands as an example, as shown in fig. 12, spectrum imaging units of wavelengths of one spectral band are arranged every four rows of common color filter arrays, and spectrum imaging units of four spectral bands are distributed in total, wherein the interval area is an RGGB pixel periodic arrangement. The pixel photosensitive units of the general image sensor are relatively large, the spectrum imaging units in four spectral bands are circularly arranged on the pixel photosensitive units, the photosensitive surface information in the period is equivalent, the uniform acquisition of target information can be realized, and the line scanning process can be avoided when the size of the target is not large.

As a thirty-fourth embodiment of the present invention, there is provided a spectral imaging system incorporating a polarization filtering structure on the basis of the foregoing embodiments. In this embodiment, the spectral imaging system includes a first light splitting structure including a plurality of spectral imaging units and a plurality of polarization filter structures, the narrow band filter films 20 of the plurality of spectral imaging units are integrally deposited and grown on the pixel photosensitive unit 10, the plurality of polarization filter structures are disposed on the pixel photosensitive unit 10, and polarization directions of the plurality of polarization filter structures are different. In the embodiment, the spectrum imaging unit and the polarization filtering structure are prepared in the same spectrum structure, and the advantages of polarization enhancement and spectrum identification are combined, so that the accuracy of target identification in a complex background environment is improved. Meanwhile, the structure is simple, the preparation process is mature, and the spectrum information and polarization information analysis algorithm is simple.

As a thirty-fifth embodiment of the present invention, there is provided a spectral imaging system, as shown in fig. 13, which introduces a full-transmission spectrum band structure on the basis of the foregoing embodiment. In this embodiment, the spectral imaging system further includes a full-spectrum-band structure, which is disposed on the pixel photosensitive unit 10. The full-spectrum band has no light splitting effect on incident light, can acquire full-spectrum band information, is used for signal compensation of a spectrum filtering structure, and particularly when the spectrum filtering structure is of a narrow-band FP cavity structure, the optical signal acquired by the sensor is weaker, and the structure can improve the signal-to-noise ratio of the sensor.

As a thirty-sixth embodiment of the present invention, there is provided a spectral imaging system, in which the first light-splitting structure includes four of the polarization filtering structures, the polarization filtering structure adopts a four-quadrant wire grid structure, and polarization angles of the four polarization filtering structures are 0 °, 45 °, 90 °, and 135 °, respectively. The polarization information in the four directions is combined to form complete polarization information of the target, and other types of polarization filtering structures are derivative-changed based on four-quadrant polarization. The four-quadrant wire grid has a simple structure, can be prepared by adopting a film, has a mature preparation process, and can comprehensively collect target polarization information.

As a thirty-seventh embodiment of the present invention, there is provided a spectral imaging system in which a plurality of spectral imaging units and a plurality of polarization filter structures together constitute n×n structures, n being a positive integer not less than 3. The structure adopts n ² -4 pixel-level narrow-band FP cavity spectrum imaging units with different center wavelengths, and randomly arranging 0 degree, 45 degree, 90 degree and 135 degree pixel-level wire grid structures. The spectrum imaging system is arranged according to the square, so that the preparation process can be simplified, and meanwhile, the polarization and spectrum information of the target can be collected uniformly, thereby being beneficial to recovering the real image.

As a thirty-eighth embodiment of the present invention, there is provided a spectral imaging system, in which the spectral imaging system includes a plurality of first spectroscopic structures, the plurality of first spectroscopic structures being periodically arranged. In this embodiment, the spectral imaging system includes a plurality of first light splitting structures, where any one of the first light splitting structures includes m×n (m×n > 4, m and n are positive integers, and m and n respectively represent the number of filter structures along a row or a column) of polarization filtering structures with different polarization directions and at least one spectral imaging unit, which are randomly arranged.

As a thirty-ninth embodiment of the present invention, there is provided a polarization-spectral filter type spectral imaging system in which, as shown in fig. 14, the first spectroscopic structure is arranged alternately with 3*3 filter structures as one period, spectral imaging units of 5 spectral bands and polarization filter structures of 4 different polarization directions. That is, when n=3, one period of the first light splitting structure is formed by arranging 4 polarization filtering structures and 5 spectrum imaging units according to a 3*3 unit structure, the polarization filtering structures and the spectrum imaging units are alternately arranged, and the 5 spectrum imaging units are in 5 different spectrum segments, so that four-adjacent-domain pixel spectrum/polarization information is formed. The polarization filter structure and the spectrum imaging unit are alternately arranged, the obtained target spectrum and polarization information are uniform, the recovery of a real image is facilitated, and the analysis and calculation are facilitated.

As a fortieth embodiment of the present invention, which is based on the foregoing embodiment, there is provided a spectral imaging system, wherein the first spectroscopic structure is a 3*3 square structure, the first spectroscopic structure includes four polarization filter structures, the four polarization filter structures are disposed in one-to-one correspondence at center positions of four outer side lengths of the square structure, and the plurality of spectral imaging units are disposed at other remaining positions of the square structure. Further, in the present invention, the spectral imaging system includes a plurality of first spectroscopic periods, and the plurality of first spectroscopic periods are periodically arranged. The spectrum imaging unit and the polarization filtering structure are prepared in the same layer of spectrum structure, and the advantages of polarization enhancement and spectrum identification are combined, so that the accuracy of target identification in a complex background environment is improved. And the spectrum imaging unit and the polarization filtering structure are uniformly distributed in the 3*3 structure period, and the target polarization and spectrum information are acquired, so that the recovery of a real image is facilitated, and the preparation process is simplified.

As a fortieth embodiment of the present invention, which is a base of the foregoing embodiment, there is provided a spectral imaging system, wherein the first spectral structure includes four polarization filter structures, the four polarization filter structures are disposed in one-to-one correspondence at a center position of an outer side length of the square structure, and the plurality of spectral imaging units and the full-spectrum structure are disposed at other remaining positions of the square structure. The full-spectrum band has no light splitting effect on incident light, can acquire full-spectrum band information, is used for signal compensation of a spectrum filtering structure, and particularly when the spectrum imaging units are all of a narrow-band FP cavity structure, the optical signals acquired by the sensor are weaker, and the structure can improve the signal-to-noise ratio of the sensor.

As a forty-second embodiment of the present invention, there is provided a spectral imaging system, in which the polarization angles of the four polarization filtering structures are respectively 0 °, 45 °, 90 ° and 135 °, and the polarization information in the four directions are combined to form complete polarization information of the target, and the other types of polarization filtering structures are derivative-changed based on four-quadrant polarization. The four-quadrant wire grid has a simple structure, can be prepared by adopting a film, has a mature preparation process, and can comprehensively collect target polarization information.

As a forty-third embodiment of the present invention, which is based on the foregoing embodiment, there is provided a spectral imaging system, as shown in fig. 15, in which the spectral imaging system includes a plurality of periodically arranged second light splitting structures, each of which is a 3*3 square structure, each of which includes at least one broad spectrum filter film structure, at least one spectral imaging unit, and four polarization filter structures, the narrow band filter film 20 of the at least one spectral imaging unit is integrally deposited and grown on the pixel photosensitive unit 10, the at least one broad spectrum filter film structure and the four polarization filter structures are each disposed on the pixel photosensitive unit 10, and the at least one broad spectrum filter film structure and the at least one spectral imaging unit are each configured to detect spectral characteristics of foods before and after maturation, and polarization directions of the four polarization filter structures are each different. The spectrum imaging system adopts a 3*3 periodic pixel-level light-splitting structure, and can simultaneously acquire image information, spectrum information and polarization information of a target to perform typical food maturity rapid detection. The household polarization-spectrum image sensor has small volume, and can be used for identifying food maturity, such as roast chicken leg maturity.

As a forty-fourth embodiment of the present invention, which is based on the foregoing embodiment, there is provided a spectral imaging system, in which any one of the second spectroscopic structures includes one wide-spectrum filter film structure, four spectral imaging units, and four polarization filter structures. The filtering information of the four narrow-band spectrum imaging units is combined with the wide-spectrum filtering information of a wide-spectrum filtering film structure, so that the spectrum leakage problem can be solved, and more narrow-band spectrum information can be extracted.

As a forty-fifth embodiment of the present invention, a forty-fourth embodiment differs from the forty-fourth embodiment in that the spectral range of the wide-spectrum filtering film structure is the characteristic spectral range before and after food maturation; the center wavelength of the spectrum of the narrow-band filtering film structure is dispersed in the characteristic spectrum ranges before and after food maturation. For the characteristic spectrum ranges before and after different foods are ripe, a wide spectrum filtering range is determined, and meanwhile, the narrow-band filtering spectrum is dispersed in the characteristic spectrum range, so that the detection accuracy can be effectively improved.

As a forty-sixth embodiment of the present invention, a forty-fifth embodiment differs from the forty-fifth embodiment in that the wide-spectrum filter film structure is a band-pass wide-spectrum filter structure. The characteristic spectrum range required by identification can be accurately obtained by adopting the band-pass broad spectrum filtering structure.

As a forty-seventh embodiment of the present invention, a difference from the foregoing embodiment is that the structure of the spectral imaging unit is an FP cavity structure. The FP cavity structure can obtain good narrow-band spectrum information, and the process is mature and convenient to prepare.

As a forty-eighth embodiment of the present invention, a difference from the forty-third embodiment is that the polarization filtering structure is a four-quadrant wire grid structure, and 4 polarization directions are 0 °,45 °,90 °,135 °, respectively. The polarization information in the four directions is combined to form complete polarization information of the target, and other types of polarization filtering structures are derivative-changed based on four-quadrant polarization. The four-quadrant wire grid has a simple structure, can be prepared by adopting a film, has a mature preparation process, and can comprehensively collect target polarization information. The four-quadrant polarization filtering structure adopts 0 degree, 45 degree, 90 degree and 135 degree angles to obtain transmission polarized light, and the polarization angle of incident light in the period is calculated according to Stokes formula. The polarized image is subjected to non-uniformity correction and interpolation calculation, so that the environment smoke interference can be resisted to a certain extent, the image quality is improved, and the oil smoke interference can be effectively avoided in cooking.

As a forty-ninth embodiment of the present invention, there is a difference from the forty-third embodiment in that four spectral imaging units are disposed in one-to-one correspondence at intermediate positions of four outer side lengths of the square structure, a wide-spectrum filter film structure is disposed at a center position of the square structure, and four polarization filter structures are disposed at remaining positions of the square structure. The center of each period is a band-pass wide-spectrum filtering structure, and the other four structures are narrow-band filtering film structures. The band-pass broad spectrum filtering structure at the center of the structure is adjacent to the four narrow-band filtering film structures, so that information calculation is facilitated.

As a fifty-first embodiment of the present invention, a polarization-spectral imaging system suitable for detection of processing maturity of a chicken leg is provided for use in identification of the maturity of a roast chicken leg. The 3*3 structure is used for arranging the polarized filter structures in four directions of 0 degree, 45 degree, 90 degree and 135 degree at four angular positions of a single period, the single period center is a 600-850nm band-pass broad spectrum filter structure, and the other four pixel photosensitive parts are narrow-band filter pixels in the pixel range of 600-850 nm.

In this embodiment, the second light splitting structure takes 3*3 filter structures as a period to form a spectrum imaging chip structure with pixel-level spectrum modulation and polarization modulation, each pixel corresponds to a filter structure individually, and single period arrangement is shown in fig. 15. The visible-near infrared 600-850nm before and after the maturation of the drumsticks is the characteristic spectrum range. With roast chicken leg as typical food, the spectral characteristics of mature chicken leg and raw chicken leg are shown in figure 16, and the spectral characteristics in the range of 600-850nm can be used for identifying and distinguishing the mature chicken leg from the raw chicken leg. Based on the above, the effective spectrum range of the image sensor is 600-850nm, the spectrum 1-spectrum 4 is a narrow-band filtering spectrum between 600-850nm, the image sensor is composed of an FP cavity structure interference film system, the center is a 600-850nm band-pass interference film system, the image sensor is used for calculating narrow-band information of the effective spectrum range together with the spectrum 1-spectrum 4, and spectrum leakage outside the effective spectrum range caused by the FP cavity film system in the spectrum 1-spectrum 4 is removed. The spectrum leakage phenomenon, as shown in fig. 17, that is, the phenomenon that incident light is totally transmitted outside the effective spectrum range, greatly reduces the signal-to-noise ratio. Therefore, 600-850nm band-pass spectrum information needs to be acquired, and typical food spectral characteristics are calculated and inverted by 4 pieces of narrowband spectrum information and band-pass spectrum information together. The four-quadrant polarization filter pixel adopts a four-angle polarization filter structure with the angle of 0 degree, 45 degrees, 90 degrees and 135 degrees to obtain four-angle transmission polarized light, and the polarization angle of incident light in the period is calculated according to a Stokes formula. The polarized image is subjected to non-uniformity correction and interpolation calculation, so that the environment smoke interference can be resisted to a certain extent, the image quality is improved, and the oil smoke interference can be effectively avoided in cooking.

As a fifty-first embodiment of the present invention, a miniaturized portable spectral imaging system is provided, which is different from the fifty-first embodiment in that the polarization-spectral imaging system for food maturity identification further includes an imaging lens, a data acquisition and processing module, and a man-machine interaction module. The imaging lens is arranged in the light incidence direction of the plurality of second light splitting structures, and the plurality of second light splitting structures are respectively connected with the data acquisition and processing module and the man-machine interaction module; the imaging lens is used for protecting the spectrum imaging chip; the data acquisition and processing module is used for acquiring image data and judging the maturity (extracting spectral information according to the acquired spectral image, comparing the spectral information with the spectral information of the mature food, and judging whether the food is mature or not); the man-machine interaction module is used for sending out an instruction to control the spectrum imaging chip to acquire images and sending the maturity information to the user side in real time. The device can realize the real-time supervision of food maturity.

The man-machine interaction module can adopt WIFI to carry out wireless communication, the spectrum imaging system is connected with the APP special for the mobile phone, and the instruction is sent and the food maturation information is received through the mobile phone.

As a fifty-second embodiment of the present invention, there is provided a monitoring method of a polarization-spectroscopic image sensor for food maturity recognition, comprising the steps of:

(1) Fixing the spectrum imaging system at a cooking place, and aligning the lens to the cooking food; (2) Controlling a spectrum imaging system to acquire spectrum images at fixed time intervals; (3) Collecting spectrum information and polarization information of a spectrum image, eliminating smoke interference through the polarization information, and judging whether food is mature or not by comparing the collected spectrum information with spectrum information of mature food; (4) If the food material is not mature, deleting the spectral image to continue to collect, and if the food material is mature, outputting food maturation information.

For example, the miniaturized portable spectrum imaging system is fixed in a cooking place, the lens is aligned with the cooking food materials, the second spectrum structure is sent out to instruct through the man-machine interaction module, the food materials in the target scene are monitored in real time, if spectrum imaging data are shot every 1s, the data are judged by the data acquisition and processing module, if the food materials are immature, the spectrum imaging data are deleted to continue shooting, if the food materials are mature, the data acquisition and processing module outputs food maturation information, and the user is reminded.

As a fifty-third embodiment of the present invention, there is provided a method of designing a polarization-spectral imaging system for food maturity identification, comprising first determining characteristic spectral ranges of a food before and after maturity; secondly, designing at least one wide-spectrum filtering film structure, wherein the spectrum range of the wide-spectrum filtering film structure covers the characteristic spectrum range; then designing at least one spectrum imaging unit, wherein the spectrum center wavelengths of a plurality of spectrum imaging units are dispersed in the characteristic spectrum range; and finally, setting the positions of a polarization filtering structure, a wide spectrum filtering film structure and a spectrum imaging unit according to the target identification requirement. By the method, a special spectral imaging system for identifying the maturity of different foods can be designed.

As a fifty-fourth embodiment of the present invention, on the basis of the foregoing embodiments, there is provided a spectral imaging system including a third spectral structure including a plurality of spectral periods distributed in a periodic manner, any spectral period including the spectral imaging unit, and narrow-band filter films 20 of the plurality of spectral imaging units being uniformly deposited and grown on the pixel photosensitive unit 10, any narrow-band filter film 20 including a plurality of FP cavity structures distributed in a mosaic manner.

In a fifty-fourth embodiment of the present invention, the handheld multispectral imager includes a third light splitting structure, where the third light splitting structure includes a plurality of spectrum periods distributed periodically, and any spectrum period includes a spectrum imaging unit, by integrally depositing and growing a narrow-band filter film on a pixel photosensitive unit, a transition layer integrally depositing and growing a narrow-band filter film on the narrow-band filter film, a first cut-off filter film integrally depositing and growing on the transition layer, no gap is formed between the first cut-off filter film, the transition layer, the narrow-band filter film and the pixel photosensitive unit, and the spectrum transmittance is high, energy loss is reduced, and the handheld multispectral imager is integrally formed by a one-step preparation process, is not polluted by external environment, has better firmness, and has higher preparation efficiency and integration level; by disposing the second cut-off filter film on the first cut-off filter film and disposing the third cut-off filter film on the second cut-off filter film, the cut-off range of the interference band can be effectively widened. In addition, because the equivalent refractive indexes of the narrow-band filter film and the first cut-off filter film are different, the peak transmittance can be influenced by direct superposition, and the peak transmittance of the image sensor can be effectively improved by arranging the transition layer between the narrow-band filter film and the first cut-off filter film. Compared with the spectrum imaging structure of the external attaching cut-off filter film in the prior art, the spectrum imaging system provided by the invention integrates the first cut-off filter film and the narrow-band filter film in the image sensor, so that the quantum efficiency and the spectrum transmittance are greatly improved; the second cut-off filter film is arranged on the first cut-off filter film, and the third cut-off filter film is arranged on the second cut-off filter film, so that the cut-off range of an interference wave band can be widened; and a transition layer is arranged between the narrow-band filter film and the first cut-off filter film, so that the peak transmittance of the image sensor is effectively improved, and the imaging effect of the handheld multispectral imager is further optimized.

As a fifty-fifth embodiment of the present invention, based on the foregoing embodiments, as shown in fig. 18, there is provided a spectral imaging system in which the third light splitting mechanism includes a 4*4-sized spectral period distributed in a periodic manner, each period includes 16 FP cavity structures of different spectral segments distributed in a mosaic manner, and a spectral image of a spectral segment corresponding to the position is obtained by extracting and combining pixel data of the same position in each period.

As a fifty-sixth embodiment of the present invention, there is provided a spectral imaging system further defined by the fifty-fifth embodiment, wherein each spectral period of the third light splitting structure further includes a plurality of polarization filtering structures having different polarization directions, and the plurality of polarization filtering structures are arranged randomly with the plurality of FP cavity structures.

In a fifty-sixth embodiment of the present invention, the spectral imaging system provided in the present embodiment has all the beneficial effects of the spectral imaging system as in the fifty-fourth embodiment, and simultaneously, the FP cavity structure of the narrow-band filter film and the polarization filter structure are prepared in the same layer of the spectroscopic structure, so that the advantages of polarization enhancement and spectrum recognition can be combined, the accuracy of target recognition in a complex background environment is improved, and the imaging effect of the spectral imaging system is further optimized. Meanwhile, the structure is simple, the preparation process is mature, and the analysis algorithm of the spectrum information and the polarization information is simple.

As a fifty-seventh embodiment of the present invention, there is provided a spectral imaging system, wherein the handheld multispectral imager is further defined by a plurality of polarization filter structures on the basis of the fifty-sixth embodiment, and wherein each spectral period includes four polarization filter structures having polarization angles of 0 °, 45 °, 90 ° and 135 °, respectively.

In a fifty-seventh embodiment of the present invention, the polarization filtering structure employs a four-quadrant wire grid structure with polarization angles of 0 °, 45 °, 90 ° and 135 °, respectively. The complete polarization information of the target can be formed by adopting the combination of the polarization information in the four directions. The four-quadrant wire grid has a simple structure, can be prepared by adopting a film, has a mature preparation process, and can comprehensively collect target polarization information. Further, on the basis of the sixteenth embodiment of the present invention, derivative changes may be performed based on four-quadrant polarization, so as to obtain other types of polarization filtering structures.

As a fifty-eighth embodiment of the present invention, a handheld multispectral imaging system is provided, which is further defined by the fifty-seventh embodiment, wherein each spectral period of the third spectral structure further includes at least one full-spectral segment structure, and the at least one full-spectral segment structure is randomly arranged with a plurality of polarization filter structures and a plurality of FP cavity structures.

In a fifty-eighth embodiment of the present invention, each spectrum period of the third spectral structure further includes at least one full-spectrum-band structure, the full-spectrum band has no spectral effect on incident light, and full-spectrum band information can be obtained for signal compensation of the spectral filtering structure, especially when the spectral imaging units are all FP cavity structures, the optical signals obtained by the spectral imaging system are weaker, and by adding the full-spectrum-band structure to the third spectral structure, the signal-to-noise ratio of the spectral imaging system can be improved, so as to optimize the imaging effect of the handheld spectral imaging system.

As a fifty-ninth embodiment of the present invention, there is provided a handheld spectral imaging system, which is further defined by the above-mentioned embodiment, wherein each spectral period of the third spectral structure further includes at least one bandpass wide-spectrum filter structure, and the at least one bandpass wide-spectrum filter structure is randomly arranged with a plurality of polarization filter structures and a plurality of FP cavity structures. In the embodiment, a specific spectrum can be transmitted through a wide spectrum filtering range through reasonable design, so that the requirements of different application scenes are met.

As a sixtieth embodiment of the present invention, there is provided a handheld spectral imaging system, which is further defined on the basis of the above-described embodiment as to the growth manner of the plurality of polarization filter structures, in which the plurality of polarization filter structures are integrally deposited and grown on the pixel photosensitive unit 10. Through depositing and growing a plurality of polarization filter structure integral type on pixel sensitization unit 10, can reduce the volume of beam splitting layer, reduce the energy loss, improve firmness, preparation efficiency and integrated level, and then optimized hand-held type spectral imaging system's imaging effect.

As a sixtieth embodiment of the present invention, as shown in fig. 19, there is provided a handheld spectral imaging system, which is further defined on the basis of the above-described embodiment, and in which the handheld spectral imaging system further includes an imaging lens group, a readout circuit and a control circuit, the imaging lens group being configured to transmit light within the spectral range index of the third spectroscopic structure, and collect the transmitted light on the pixel photosensitive unit 10; the readout circuit is connected with the pixel photosensitive unit 10; the control circuit comprises a processor and a communication module, and the processor is respectively connected with the reading circuit and the communication module.

In a sixty-first embodiment of the present invention, the hand-held spectral imaging system uses the imaging lens group to transmit the light in the spectral range index of the third spectral structure and collect the light on the pixel photosensitive unit, uses the readout circuit to read the pixel data of the pixel photosensitive unit, uses the processor of the control circuit to perform image processing, and uses the communication module to transmit the final image processing result to the outside, thereby realizing the acquisition of the spectral image. The handheld spectrum imaging system provided by the embodiment has the advantages that the handheld spectrum imaging system in the embodiment has the advantages that no gap exists among the first cut-off filter film, the narrow-band filter film and the pixel photosensitive unit, the spectrum transmittance is high, the energy loss is reduced, the one-step preparation process is integrated, the environment pollution is avoided, the firmness is better, the preparation efficiency and the integration level are higher, the quantum efficiency and the spectrum transmittance are greatly improved, and the imaging effect of the handheld spectrum imaging system is further optimized.

As a sixtieth embodiment of the present invention, a handheld spectral imaging system is provided, which is further defined on the basis of the sixtieth embodiment, wherein the control circuit further comprises a power supply module, which is respectively connected to the image sensor, the processor and the communication module, for providing power support for the handheld spectral imaging system.

As a sixty-third embodiment of the present invention, a handheld spectral imaging system is provided, which is further defined on the basis of the sixty-first embodiment, wherein the communication module is configured as a wireless communication module, and the wireless communication module performs signal interaction with an external device. For example, the communication module can generate a Wifi hotspot to be connected with an external matched smart phone so as to transmit image signals and control information. In this particular embodiment, the human-machine interaction part is implemented by a smart phone through a dedicated APP. The special APP operated by the matched smart phone has the following functions: the handheld spectrum imaging system is connected to perform data interaction through the Wifi function of the mobile phone; the imaging system is provided with a graphical man-machine interaction interface, and can display the spectrum image acquired by the handheld spectrum imaging system in real time; the mobile phone image acquisition control is provided with an image acquisition control, and after clicking the image acquisition control, the current frame image can be stored in a mobile phone storage space; the method has the function of checking the specific spectrum, and only the image of the selected spectrum can be displayed after clicking to check the specific spectrum; the system has the function of checking the spectral reflectance curve at the specific position, and the spectral reflectance curve at the current position is displayed after clicking and checking the spectral reflectance curve at the specific position.

As a sixty-fourth embodiment of the present invention, there is provided a line-scan type spectral imaging system including at least one spectral imaging chip structure, any one of which includes a pixel photosensitive unit 10 and a spectral imaging unit, and a narrow-band filter 20 including a plurality of FP cavity structures distributed in a line-scan type, the FP cavity structures being different in height in a spectral dimension direction and the FP cavity structures being identical in height in a spatial dimension direction.

In a sixty-fourth embodiment of the present invention, the line scanning type spectral imaging system includes at least one spectral imaging chip structure, where a narrow-band filter film is integrally deposited and grown on a pixel photosensitive unit, a transition layer is integrally deposited and grown on the narrow-band filter film, a first cut-off filter film is integrally deposited and grown on the transition layer, no gap is formed between the first cut-off filter film, the transition layer, the narrow-band filter film and the pixel photosensitive unit, the spectral transmittance is high, the energy loss is reduced, the one-time preparation process is integrally formed, no external environmental pollution is caused, the firmness is better, and the preparation efficiency and the integration are higher; by disposing the second cut-off filter film on the first cut-off filter film and disposing the third cut-off filter film on the second cut-off filter film, the cut-off range of the interference band can be effectively widened. In addition, as the equivalent refractive indexes of the narrow-band filter film and the first cut-off filter film are different, the peak transmittance can be influenced by direct superposition, and the peak transmittance of the spectrum imaging chip structure can be effectively improved by arranging the transition layer between the narrow-band filter film and the first cut-off filter film. Compared with the external attaching cut-off filter film in the prior art, the spectrum imaging system provided by the invention integrates the first cut-off filter film and the narrow-band filter film in the spectrum imaging chip structure, so that the quantum efficiency and the spectrum transmittance are greatly improved; the second cut-off filter film is arranged on the first cut-off filter film, and the third cut-off filter film is arranged on the second cut-off filter film, so that the cut-off range of an interference wave band can be widened; and a transition layer is arranged between the narrow-band filter film and the first cut-off filter film, so that the peak transmittance of the spectrum imaging system is effectively improved, and the imaging effect of the line scanning spectrum imaging system is further optimized.

As a sixty-fifth embodiment of the present invention, there is provided a line-scan type spectral imaging system, wherein the number of the spectral imaging chip structures is further defined on the basis of the sixty-fourth embodiment. In the invention, the number of the spectrum imaging chip structures and the spectrum ranges corresponding to the chips can be set according to the actual demands of users. In this embodiment, the line scan spectral imaging system includes four spectral imaging chip structures that cover in sequence spectral ranges of 400-510 nm, 510-630 nm, 640-810 nm, and 800-1000 nm.

As a sixty-sixth embodiment of the present invention, there is provided a line-scan type spectral imaging system, which is further defined on the basis of the sixty-fourth embodiment, in which the spectral imaging chip structure further includes a plurality of color filter groups, the narrow band filter films 20 of the plurality of spectral imaging units are sequentially deposited and grown on the pixel photosensitive unit 10 in a single-unit manner in the spectral dimension direction, the plurality of color filter groups are sequentially deposited and grown on the pixel photosensitive unit 10 in a single-unit manner in the spectral dimension direction, and one color filter group is disposed between any two adjacent spectral imaging units.

In the sixty-sixth embodiment of the present invention, the line-scan spectral imaging system provided in the present embodiment has all the advantages of the line-scan spectral imaging system as in the sixty-fourth embodiment, and at the same time, the embodiment combines the advantages of the spectral imaging chip and the RGB image sensor, and by distributing the color filter groups periodically arranged in a plurality of columns along the spectral dimension direction at a plurality of columns FP cavity structures on the pixel photosensitive unit 10, it is possible to combine the high-resolution imaging of the common RGB image sensor while realizing the spectral imaging, and improve the color reduction effect and the image resolution of the image.

As a sixty-seventh embodiment of the present invention, there is provided a line-scan spectral imaging system, which is based on the above-described embodiment, in which the specific structure of the color filter group is further defined, and in this embodiment, the color filter group is one of an RGGB color filter structure, a RYYB color filter structure, or an RGWB color filter structure. The specific structure of the color filter group can be selected according to the specific application environment in practical application.

As a sixty-eighth embodiment of the present invention, there is provided a line-scan type spectral imaging system, which is further defined on the basis of the sixty-fourth embodiment, wherein the number of columns of the interval between any two adjacent columns of FP cavity structures is not less than 4. Since a typical bayer array is a 4×4 array, which is composed of 8 green, 4 blue and 4 red pixels, 9 operations are performed in a 2×2 matrix when converting a gray pattern into a color picture, and finally a color pattern is generated. Therefore, the number of columns of the interval between any two adjacent columns of FP cavity structures is generally not less than 4, so that the image analysis and calculation are facilitated. As shown in fig. 12, the number of the spaced columns between any two adjacent FP cavity structures is 8 columns.

As a sixty-ninth embodiment of the present invention, as shown in fig. 20, a line scanning type spectrum imaging system is provided, where the line scanning type spectrum imaging system is further defined on the basis of the above embodiment, and in this embodiment, the line scanning type spectrum imaging system further includes an imaging lens group, a sensor adapter plate, an embedded information processing plate, a push-broom system and an upper computer, where the imaging lens group is used to transmit light within a spectrum range index of the spectrum imaging system, and collect the transmitted light on the sensor adapter plate; the sensor adapter plate is used for carrying at least one spectrum imaging chip structure, and light transmitted by the imaging lens group is converged on the spectrum imaging chip structure on the sensor adapter plate; the embedded information processing board is connected with the sensor adapter plate and is used for supplying power to the sensor adapter plate and performing signal interaction, and processing and integrating image information of the sensor adapter plate; the push-broom system is used for carrying a sensor adapter plate and an embedded information processing plate, and moves push-broom along the direction of the spectrum dimension; the upper computer is respectively connected with the push-broom system and the embedded information processing board, and is used for controlling the mobile push-broom of the push-broom system and acquiring a complete spectrum image according to the image information integrated by the embedded information processing board.

In a sixty-ninth embodiment of the present invention, the line scanning type spectral imaging system achieves acquisition of a spectral image by mounting at least one spectral imaging chip structure on a sensor adapter plate, and combining an imaging lens group, the sensor adapter plate, an embedded information processing plate, a push-broom system and an upper computer. The line scanning type spectrum imaging system provided by the embodiment has the advantages that the line scanning type spectrum imaging system has the advantages that gaps are not formed among the first cut-off filter film, the narrow-band filter film and the pixel photosensitive units, the spectrum transmittance is high, the energy loss is reduced, the one-step preparation process is integrated, the line scanning type spectrum imaging system is not polluted by external environment, the firmness is better, the preparation efficiency and the integration level are higher, the quantum efficiency and the spectrum transmittance are greatly improved, and the imaging effect of the line scanning type spectrum imaging system is optimized.

As a seventeenth embodiment of the present invention, there is provided a line scanning type spectral imaging system, which is further defined on the basis of the sixty-ninth embodiment, in which an embedded information processing board may be connected to a sensor patch board through a Flexible circuit board (Flexible PrintedCircuit, FPC) or a board-to-board connector, and the embedded information processing board may employ an FPGA or an SoC chip. The stable electric connection and signal transmission between the embedded information processing board and the sensor adapter board can be realized through the flexible circuit board or the board-to-board connector.

As a seventy-first embodiment of the present invention, there is provided a spectral imaging system, wherein the film system structure of the spectral imaging system is further defined on the basis of the seventy-first embodiment, in which the film system structure of the narrow-band filter film 20 of any one of the spectral imaging chip structures is H (LH)/(S2 nL (HL)/(SH), n is a film thickness adjustment coefficient, S is the number of stacks, H is a high refractive index material, L is a low refractive index material, the film thickness adjustment coefficients n of the four spectral imaging chip structures are all different, and the film thickness adjustment coefficients n are equally divided into the corresponding spectral segments.

As a seventy-second embodiment of the present invention, there is provided a spectral imaging system, which is based on the seventy-first embodiment, and in a spectral dimension direction, four spectral imaging chip structures are a line scan chip of 16 spectrum segments in a range of 400nm to 510nm, a line scan chip of 32 spectrum segments in a range of 510nm to 630nm, a line scan chip of 32 spectrum segments in a range of 640nm to 810nm, and a line scan chip of 32 spectrum segments in a range of 800nm to 1000nm in order. Along the direction of the spectrum dimension, the value ranges of the film thickness adjusting coefficients n corresponding to the four spectrum imaging chip structures are designed to be 0.745-1.557, 0.67-1.439, 0.643-1.425 and 0.652-1.437 in sequence.

As a seventy-third embodiment of the present invention, on the basis of the foregoing embodiment, there is provided a method of manufacturing a spectral imaging system, the method comprising: step one, dividing the pixel photosensitive unit 10 into a plurality of pixel areas along the direction of the spectrum dimension; and secondly, sequentially and respectively integrally depositing and growing a plurality of spectrum imaging units on the plurality of pixel areas, wherein the spectrum imaging units are used for realizing narrow-band filtering, and the plurality of spectrum imaging units respectively cover different spectrum ranges. In this embodiment, the pixel photosensitive unit may be a CMOS pixel photosensitive unit. In this embodiment, the spectral range required to be covered by each spectral imaging unit may be designed according to the narrow-band filtering spectral range (e.g., the range 490-900 nm for visible light) required to be satisfied by the spectral imaging system. And splitting pixel areas of the pixel photosensitive units according to the number of the designed spectrum imaging units. Therefore, the method of the embodiment of the invention divides the pixel photosensitive unit into a plurality of pixel areas, and sequentially and respectively deposits and grows a plurality of spectrum imaging units (namely, different spectrum imaging units and the image sensor are integrally processed in a single chip) on the plurality of pixel areas, the spectrum structure covers different spectrum ranges, the limitation of the material refractive index difference on the free spectrum range is broken through, the free spectrum range of narrow-band filtering of the single chip image sensor is widened, and the micro photoelectric image chip structure with high extinction ratio and narrow-band spectrum characteristic in the visible spectrum range (490-900 nm) is obtained.

According to a seventy-fourth embodiment of the present invention, in order to achieve preparation of a plurality of spectroscopic structures, step two includes: 2.1, depositing a removing layer on the whole pixel area (namely the pixel of the wafer sensor) of the pixel photosensitive unit; 2.2 preparing a first spectral imaging unit along a pixel direction a, comprising: 2.21, removing the removing layer on the first pixel area corresponding to the first spectrum imaging unit; 2.22 preparing a first spectral imaging unit on the structure obtained in step 2.21 based on the raw material of the first spectral imaging unit; 2.3, removing the redundant removing layer, and integrally depositing the removing layer on the structure obtained in the step 2.2; 2.4 preparing a second spectral imaging unit along a pixel direction a, comprising: 2.41, removing the removing layer on the second pixel area corresponding to the second spectrum imaging unit; 2.42 preparing a second spectral imaging unit on the structure obtained in step 2.41 based on the starting material of the second spectral imaging unit; 2.5, and the like, adopting the same process as the steps 2.3-2.4 to sequentially prepare the rest spectrum imaging units.

In this embodiment, the removal layer is introduced to prepare a plurality of spectral imaging units, specifically: preparing a first spectrum imaging unit along a pixel direction a, namely, firstly depositing a removal layer on the whole pixel photosensitive unit, then exposing a pixel area corresponding to the first spectrum imaging unit, removing the removal layer of the pixel area, then depositing raw materials of the first spectrum imaging unit on the whole pixel photosensitive unit (comprising a region containing the removal layer and a region not containing the removal layer), and then removing the removal layer to finish the preparation of the first spectrum imaging unit in the first pixel area; then, the second spectral imaging unit is prepared, firstly, a removing layer is required to be deposited on the whole pixel photosensitive unit (at the moment, the removing layer is also arranged on the first spectral imaging unit), then the removing layer of the second pixel area is exposed, the removing layer is arranged in the other areas, then, the second spectral imaging unit is prepared by adopting the same process as the first spectral imaging unit, the raw material of the second spectral imaging unit is deposited, then, the removing layer is removed, and then, the preparation of the second spectral imaging unit can be completed in the second pixel area, and the third spectral imaging unit, the fourth spectral imaging unit and the like are prepared. In this way, co-deposition growth of different spectral imaging units on the same pixel photosensitive unit is achieved.

In this embodiment, it should be understood by those skilled in the art that the same process as steps 2.3-2.4 is used to sequentially prepare the rest of the spectral imaging units, where the same process refers to the same preparation means, such as preparing the third spectral imaging unit, then the raw material of the third spectral imaging unit must also be used in step 2.4, and so on, and the rest correspondingly changes.

According to a seventy-fifth embodiment of the present invention, in order to remove the excessive removal layer, in the step 2.21, the removal layer on the first pixel area may be removed by photolithography and etching. In this embodiment, the processes of photolithography, etching, etc. are conventional technical means in the art, and detailed descriptions thereof are omitted.

According to a seventy-sixth embodiment of the present invention, in order to expose the pixel regions corresponding to the remaining spectral imaging units except for the first spectral imaging unit, the removal layer on the second pixel region is removed by the removal layer inverse lithography and etching in the preparation of the second spectral imaging unit, and the removal layer of the corresponding region is removed by the same method in the preparation of the remaining spectral imaging unit in step 2.5.

In this embodiment, the removal layer on the required pixel area needs to be removed by the removal layer inverse lithography and etching under the condition that the spectral imaging unit is already present on the pixel photosensitive unit.

According to a seventy-seventh embodiment of the present invention, in order to implement narrow-band filtering, the spectral imaging unit adopts a line-scan FP filter structure, including a plurality of FP cavities, and heights of the plurality of FP cavities of any spectral imaging unit are graded along a spectral dimension direction, where the FP cavities include an upper mirror, a light-passing layer, and a lower mirror, and accordingly, in the method, any process for preparing the spectral imaging unit on a corresponding structure based on raw materials of the spectral imaging unit includes performing deposition of the lower mirrors of the plurality of FP cavities; depositing a light transmission layer on the lower reflecting mirror; carrying out m times of photoetching and etching on the light passing layer part on the pixel area corresponding to the spectrum imaging unit to obtain a light passing layer with a step structure, wherein the number of spectral bands of the spectrum imaging unit is equal to 2 ^m The spectrum ranges of the plurality of spectrum imaging units are the same or different or partially the same; and depositing upper reflectors of a plurality of FP cavities on the light transmission layer of the step structure or the whole structure.

As a seventy-eighth embodiment of the present invention, there is provided an imaging method of a line-scan spectral imaging system that performs spectral imaging using the line-scan spectral imaging system as described above, in which the imaging method of the line-scan spectral imaging system includes: the upper computer controls the push-broom system to move along the direction of the spectrum dimension according to the preset push-broom speed; after the moving speed of the push-broom system is stable, the embedded information processing board acquires at least one spectrum imaging chip structure image at a preset frame rate, integrates the images and uploads the images to the upper computer; and the upper computer extracts a specific spectrum part in each frame of image and splices the specific spectrum part to acquire a complete spectrum image of the spectrum part in a scanning range. By applying the imaging method of the line-scan type spectrum imaging system, the quantum efficiency and the spectrum transmittance are greatly improved, and the imaging effect of the line-scan type spectrum imaging system is optimized.

As a seventy-ninth embodiment of the present invention, there is provided an imaging method of a line-scan spectral imaging system, which is further defined on the basis of the twenty-ninth embodiment, wherein the preset push-scan speed satisfies V _min ≥L/f _frame Wherein V is _min For a minimum preset push-broom speed of the push-broom system, L is the length of the FP cavity step width mapped onto the imaging object plane, L/l=d/f _focus =2tan θ, l is the step width, D is the distance from the optical center of the imaging lens set to the object plane, f _focus For the focal length of the imaging lens group, θ is the angle of view of the imaging lens group, f _frame Is the image frame rate.

Spatially relative terms, such as "above … …," "above … …," "upper surface at … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations of "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present invention.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A spectral imaging system, characterized in that the spectral imaging system comprises a pixel light sensing unit (10) and a spectral imaging unit, the pixel light sensing unit (10) being adapted to enable image acquisition and data readout, the spectral imaging unit comprising:

the narrow-band optical filter film (20), the narrow-band optical filter film (20) is integrally deposited and grown on the pixel photosensitive unit (10), and the narrow-band optical filter film (20) is used for realizing the tunability of the central wavelength of a required wave band;

the transition layer (40) is integrally deposited and grown on the narrow-band filter film (20), and the transition layer (40) is used for transiting two film systems of the narrow-band filter film (20) and the first cut-off filter film (30);

A first cut-off filter film (30), wherein the first cut-off filter film (30) is integrally deposited and grown on the narrow-band filter film (20), and the first cut-off filter film (30) is used for cutting off a first interference wave band;

a second cut-off filter film (60), the second cut-off filter film (60) being disposed on the first cut-off filter film (30), the second cut-off filter film (60) being configured to cut off a second interference band, the second interference band being different from the first interference band;

and a third cut-off filter film (70), wherein the third cut-off filter film (70) is arranged on the second cut-off filter film (60), and the third cut-off filter film (70) is used for cutting off a third interference wave band, and the third interference wave band is different from the first interference wave band and the second interference wave band.

2. The spectral imaging system of claim 1, wherein the second cut-off filter film (60) is integrally deposited and grown on the first cut-off filter film (30), and the third cut-off filter film (70) is integrally deposited and grown on the second cut-off filter film (60).

3. The spectral imaging system of claim 1, wherein the second cut-off filter film (60) is integrally deposited on the first cut-off filter film (30), and the third cut-off filter film (70) is adhesively disposed on the second cut-off filter film (60).

4. The spectral imaging system according to claim 1, wherein the second cut-off filter film (60) is adhesively arranged on the first cut-off filter film (30), and the third cut-off filter film (70) is adhesively arranged on the second cut-off filter film (60).

5. The spectral imaging system of any of claims 1 to 4, wherein the spectral imaging unit further comprises a matching layer (50), the matching layer (50) being integrally deposited on the pixel light sensing unit (10), the matching layer (50) being configured to transition optical admittances between the light sensing unit (10) and the narrow band filter film (20), the transition layer (40), the first cut-off filter film (30), the second cut-off filter film (60) and the third cut-off filter film (70) to increase a center wavelength peak transmittance; the narrow band filter film (20) is integrally deposited and grown on the matching layer (50).

6. The spectral imaging system of claim 5, wherein the spectral imaging unit has a film-based structureIs sub|HL H (LH) ≡S ₁ 2nL(HL)^S ₁ H L n ₁ (W1)^S ₂ n ₂ (W2)^S ₃ n ₃ (W3)^S ₄ I Air, HL is the film structure of the matching layer (50), H (LH) ≡S ₁ 2nL(HL)^S ₁ H is the film structure of the narrow band filter film (20), L is the film structure of the transition layer (40), n ₁ (W1)^S ₂ Is a film system structure of the first cut-off filter film (30), n ₂ (W2)^S ₃ Is a film system structure of the second cut-off filter film (60), n ₃ (W3)^S ₄ For the film system structure of the third stop filter film (70), W1, W2 and W3 each comprise a high refractive index material and a low refractive index material, H is a high refractive index material, L is a low refractive index material, S ₁ 、S ₂ 、S ₃ And S is ₄ For the number of overlapping times, n is the film thickness adjustment coefficient of the narrow-band filter film (20), n ₁ For the film thickness adjustment coefficient, n, of the first cut-off filter film (30) ₂ For the film thickness adjustment coefficient, n, of the second cut-off filter film (60) ₃ And adjusting a coefficient for the film thickness of the third stop filter film (70).

7. The spectral imaging system of claim 1, wherein any of said cutoff filter films is fabricated using alternating deposition of a high refractive index material and a low refractive index material, the high refractive index material of any of said cutoff filter films comprising Ta ₂ O ₅ 、Ti ₃ O ₅ 、TiO ₂ 、Si ₃ N ₄ Or Nb (Nb) ₂ O ₅ The low refractive index material of any one of the cut-off filter films comprises SiO ₂ 、MgF ₂ And Al ₂ O ₃ At least one of them.

8. The spectral imaging system according to claim 1, wherein the narrow-band filter film comprises a plurality of FP cavity structures, the FP cavity structures are formed by a semiconductor process at one time, any FP cavity structure comprises a first mirror, a light-transmitting layer and a second mirror which are sequentially stacked from bottom to top, the FP cavity structures are distributed in a mosaic shape, the heights of the light-transmitting layers of the FP cavity structures along any column of the narrow-band filter film are different, and the heights of the light-transmitting layers of the FP cavity structures along any row of the narrow-band filter film are different; or a plurality of FP cavity structures are distributed in a line scanning mode, the heights of the light transmission layers of the FP cavity structures along any one row of the narrow-band filter film are identical, and the heights of the light transmission layers of the FP cavity structures along any one row of the narrow-band filter film are different.

9. The spectral imaging system of any of claims 1 to 8, wherein the film thickness adjustment factor is obtainable according to the steps of: determining a spectrum section to be cut off of any cut-off filter film; calculating and obtaining the center wavelength of the spectrum segment to be cut according to the first boundary threshold value and the second boundary threshold value of the spectrum segment to be cut; and determining a film layer thickness adjustment coefficient of any cut-off filter film according to the central wavelength of the to-be-cut-off spectrum and the central wavelength of the narrow-band filter film.

10. The spectral imaging system of claim 9, wherein the center wavelength of the spectral band to be cut-off is dependent on

Is obtained by, wherein lambda ₀ Lambda is the center wavelength of the spectrum to be cut-off ₁ For a first boundary threshold, lambda, of the spectral band to be cut ₂ And a second boundary threshold value of the spectrum segment to be cut off.

11. The spectral imaging system of claim 9, wherein the center wavelength of the spectral band to be cut-off is dependent on

12. A spectral imaging system according to claim 10 or 11, wherein the film thickness adjustment factor n of the cut-off filter film is dependent on

Wherein λ is the center wavelength of the narrow band filter, n=n ₁ 、n ₂ Or n ₃ 。

13. The spectral imaging system according to any of claims 1 to 5, wherein the spectral imaging system comprises a plurality of the spectral imaging units, the pixel light sensing unit (10) being divided into a plurality of pixel areas in a spectral dimension direction; narrow-band filter films (20) of a plurality of spectrum imaging units are respectively deposited and grown on a plurality of pixel areas in one-to-one correspondence.

14. The spectral imaging system according to claim 13, wherein the narrow-band filter film (20) of any one of the spectral imaging units comprises a plurality of FP cavity structures, the FP cavity structures are formed at one time by a semiconductor process, each FP cavity structure comprises a first reflecting mirror, a light-transmitting layer and a second reflecting mirror which are sequentially stacked from bottom to top, the FP cavity structures are distributed in a line scan manner, the heights of the light-transmitting layers of the FP cavity structures along the spatial dimension of the narrow-band filter film are the same, and the heights of the light-transmitting layers of the FP cavity structures along the spectral dimension of the narrow-band filter film are different.

15. The spectral imaging system according to any of claims 1 to 5, wherein the spectral imaging system comprises a first spectral imaging unit and a second spectral imaging unit, the pixel light sensing unit (10) being divided into a first pixel area and a second pixel area in a spectral dimension direction; the narrow-band filter film (20) of the first spectrum imaging unit is integrally deposited and grown on the first pixel area, and the narrow-band filter film (20) of the second spectrum imaging unit is integrally deposited and grown on the second pixel area.

16. The spectral imaging system of claim 15, wherein the first spectral imaging unit covers a spectral range of 490nm to 620nm and the second spectral imaging unit covers a spectral range of 650nm to 1000nm.

17. The spectral imaging system of claim 15, wherein the narrow band filter (20) of the first spectral imaging unit comprises a plurality of FP cavity structures, each of the FP cavity structures being formed by a semiconductor process, any one of the FP cavity structures comprising a first mirror, a first light transmissive layer, and a second mirror stacked in sequence from bottom to top, the plurality of FP cavity structures being distributed in a line scan, the first mirror being formed by alternately preparing a plurality of layers of high reflectivity material and a plurality of layers of low reflectivity material, the second mirror having a structure identical to that of the first mirror, the first light transmissive layer being formed by deposition growth of a low reflectivity material, wherein the high reflectivity material comprises SI ₃ N ₄ The low reflectivity material comprises SIO ₂ 。

18. The spectral imaging system of claim 15, wherein the narrow-band filter (20) of the second spectral imaging unit comprises a plurality of FP cavity structures, each of the FP cavity structures being formed by a semiconductor process, any one of the FP cavity structures comprising a third mirror, a second light-passing layer, and a fourth mirror stacked in sequence from bottom to top, the FP cavity structures being distributed in a line scan, the third mirror being formed by alternately providing a plurality of layers of high-reflectivity material and a plurality of layers of low-reflectivity material, the fourth mirror having a structure identical to the third mirror, the second light-passing layer being formed by deposition growth of a low-reflectivity material, wherein the high-reflectivity material comprises α -SI, and the low-reflectivity material comprises SIO ₂ 。

19. The spectral imaging system according to any of claims 1 to 6, wherein the spectral imaging system comprises a third spectral imaging unit, a fourth spectral imaging unit and a fifth spectral imaging unit, the pixel light sensing unit (10) being divided into a third pixel area, a fourth pixel area and a fifth pixel area in a spectral dimension direction; the narrow-band filter film (20) of the third spectrum imaging unit is integrally deposited and grown on the third pixel area, the narrow-band filter film (20) of the fourth spectrum imaging unit is integrally deposited and grown on the fourth pixel area, and the narrow-band filter film (20) of the fifth spectrum imaging unit is integrally deposited and grown on the fifth pixel area.

20. The spectral imaging system of claim 19, wherein the third spectral imaging unit covers a spectral range of 490nm to 620nm, the fourth spectral imaging unit covers a spectral range of 640nm to 800nm, and the fifth spectral imaging unit covers a spectral range of 800nm to 1000nm.

21. The spectral imaging system of claim 19, wherein the narrow band filter (20) of any of the spectral imaging units comprises a plurality of FP cavity structures, each of the FP cavity structures being formed by a semiconductor process, each of the FP cavity structures comprising a first reflector, a light transmissive layer, and a second reflector stacked in sequence from bottom to top, the plurality of FP cavity structures being distributed in a line scan, the first reflector being formed by alternating layers of high reflectivity material and low reflectivity material, the second reflector having a structure identical to that of the first reflector, the first light transmissive layer being formed by deposition growth of a low reflectivity material, wherein the high reflectivity material comprises SI ₃ N ₄ The low reflectivity material comprises SIO ₂ 。

22. The spectral imaging system according to any one of claims 1 to 6, wherein the spectral imaging system comprises a plurality of spectral imaging units and a plurality of color filter groups, wherein narrow-band filter films (20) of the plurality of spectral imaging units are sequentially deposited and grown on the pixel photosensitive units (10) in an integrated manner at intervals, the plurality of color filter groups are sequentially deposited and grown on the pixel photosensitive units (10) in an integrated manner at intervals, and one color filter group is arranged between any two adjacent spectral imaging units.

23. The spectral imaging system of claim 22, wherein a line spacing between any two adjacent spectral imaging units is greater than or equal to 4.

24. The spectral imaging system of claim 22, wherein any of the color filter groups comprises an RGGB color filter structure, RYYB color filter structure, or an RGWB color filter structure.

25. The spectral imaging system of claim 22, wherein any one of the spectral imaging units corresponds to a central wavelength, and wherein the central wavelengths of the plurality of spectral imaging units sequentially taper.

26. The spectral imaging system of any of claims 1 to 5, wherein the spectral imaging system comprises a first spectral structure comprising a plurality of spectral imaging units and a plurality of polarization filtering structures, wherein narrow band filter films (20) of the plurality of spectral imaging units are integrally deposited and grown on the pixel photosensitive unit (10), wherein the plurality of polarization filtering structures are arranged on the pixel photosensitive unit (10), and wherein polarization directions of the plurality of polarization filtering structures are different.

27. The spectral imaging system of claim 26, further comprising a full-transmission spectrum segment structure disposed on the pixel-photosensitive unit (10).

28. The spectral imaging system of claim 26, wherein the first light splitting structure comprises four of the polarizing filter structures having polarization angles of 0 °, 45 °, 90 °, and 135 °, respectively.

29. The spectral imaging system of claim 26, wherein a plurality of the spectral imaging units and a plurality of polarization filtering structures together form n x n structures, n being a positive integer not less than 3.

30. The spectral imaging system of claim 26, wherein the spectral imaging system comprises a plurality of the first spectral structures, the plurality of first spectral structures being arranged periodically.

31. The spectral imaging system of claim 26, wherein the first light splitting structure is a 3*3 square structure, the first light splitting structure comprises four polarization filter structures, the four polarization filter structures are arranged in a one-to-one correspondence manner at the center positions of four outer side lengths of the square structure, and a plurality of the spectral imaging units are arranged at other remaining positions of the square structure.

32. The spectral imaging system of claim 27, wherein the first light splitting structure is a 3*3 square structure, the first light splitting structure comprises four polarization filter structures, the four polarization filter structures are arranged in a one-to-one correspondence manner at a central position of an outer side length of the square structure, and the plurality of spectral imaging units and the full-transmission spectrum structure are arranged at other remaining positions of the square structure.

33. The spectral imaging system of claim 31 or 32, wherein the polarization angles of the four polarization filtering structures are 0 °, 45 °, 90 ° and 135 °, respectively.

34. The spectral imaging system according to any of claims 1 to 5, wherein the spectral imaging system comprises a plurality of periodically arranged second light splitting structures, each of the second light splitting structures is a 3*3 square structure, each of the second light splitting structures comprises at least one broad spectrum filter film structure, at least one spectral imaging unit and four polarization filter structures, a narrow band filter film (20) of at least one spectral imaging unit is integrally deposited and grown on the pixel photosensitive unit (10), at least one broad spectrum filter film structure and four polarization filter structures are arranged on the pixel photosensitive unit (10), and at least one broad spectrum filter film structure and at least one spectral imaging unit are used for detecting spectral characteristics before and after food ripening, and polarization directions of the four polarization filter structures are different.

35. The spectral imaging system of claim 34, wherein any of the second light splitting structures comprises one of the broad spectrum filter film structures, four of the spectral imaging units, and four of the polarization filter structures.

36. The spectral imaging system of claim 34, wherein any of the spectral imaging units is an FP cavity structure.

37. The spectral imaging system of claim 35, wherein the broad spectrum filtering thin film structure is a bandpass broad spectrum filtering structure.

38. The spectral imaging system of claim 34, wherein four spectral imaging units are disposed in one-to-one correspondence with each other at intermediate positions of four outer side lengths of the square structure, wherein the wide spectrum filter film structure is disposed at a center position of the square structure, and wherein four polarization filter structures are disposed at remaining positions of the square structure.

39. The spectral imaging system of claim 34, further comprising an imaging lens, a data acquisition and processing module, and a human-machine interaction module, wherein the imaging lens is disposed in a light incidence direction of a plurality of the second light splitting structures, and the plurality of the second light splitting structures are respectively connected with the data acquisition and processing module and the human-machine interaction module; the data acquisition and processing module is used for acquiring image data and judging the maturity according to the image data, and the man-machine interaction module is used for controlling the plurality of second light splitting structures to acquire images and sending the maturity information to the user side in real time.

40. The spectral imaging system of any of claims 1 to 5, wherein the spectral imaging unit comprises a third spectral structure comprising a plurality of spectral periods distributed in a periodic manner, any one of the spectral periods comprising the spectral imaging unit, a plurality of narrow band filter films (20) of the spectral imaging unit being deposited and grown uniformly on the pixel photosensitive unit (10), any one of the narrow band filter films (20) comprising a plurality of FP cavity structures distributed in a mosaic.

41. The spectral imaging system of claim 40, wherein any one of said spectral periods further comprises a plurality of polarization filtering structures having different polarization directions, a plurality of said polarization filtering structures being randomly arranged with said plurality of FP cavity structures.

42. The spectral imaging system of claim 41, wherein any one of the spectral periods comprises four polarization filtering structures having polarization angles of 0 °, 45 °, 90 ° and 135 °, respectively.

43. The spectral imaging system of claim 40 or 41, wherein any one of the spectral periods further comprises at least one fully-transparent spectral band structure, the plurality of polarization filtering structures, and the plurality of FP cavity structures being randomly arranged.

44. The handheld multispectral imager of claim 40 or 41, wherein any one of the spectral periods further comprises at least one bandpass broad spectrum filter structure, the plurality of polarization filter structures, and the plurality of FP cavity structures are arranged randomly.

45. A spectral imaging system according to claim 41, wherein a plurality of the polarizing filter structures are grown integrally deposited on the pixel light sensitive unit (10).

46. The spectral imaging system of claim 40, wherein the spectral imaging system further comprises:

the imaging lens group is used for transmitting light in the spectrum range index of the third light splitting structure and converging the transmitted light on the pixel photosensitive unit (10);

a readout circuit connected to the pixel photosensitive unit (10);

the control circuit comprises a processor and a communication module, and the processor is respectively connected with the reading circuit and the communication module.

47. The spectral imaging system according to any of claims 1 to 5, wherein the spectral imaging system comprises at least one spectral imaging chip structure, any of which comprises the pixel light sensing unit (10) and the spectral imaging unit, the narrow-band filter film (20) comprises a plurality of FP cavity structures distributed in a line-scan manner, the FP cavity structures in the spectral dimension direction are different in height, and the FP cavity structures in the spatial dimension direction are the same in height.

48. The spectral imaging system of claim 47, wherein the line scan spectral imaging system comprises four spectral imaging chip structures that cover in sequence spectral ranges of 400-510 nm, 510-630 nm, 640-810 nm, and 800-1000 nm.

49. The spectral imaging system of claim 47, wherein any one of the spectral imaging chip structures further comprises a plurality of color filter groups, the narrow-band filter films (20) of the plurality of spectral imaging units are sequentially deposited and grown on the pixel photosensitive units (10) at intervals in a spectral dimension direction, the plurality of color filter groups are sequentially deposited and grown on the pixel photosensitive units (10) at intervals in the spectral dimension direction, and one color filter group is arranged between any two adjacent spectral imaging units.

50. The spectral imaging system of claim 49, wherein any of the color filter groups is one of an RGGB color filter structure, a RYYYB color filter structure, or an RGWB color filter structure.

51. The spectral imaging system of claim 47, wherein the spectral imaging system further comprises:

The imaging lens group is used for transmitting light in the spectrum range index of the spectrum imaging system;

the sensor adapter plate is used for carrying at least one spectrum imaging chip structure, and light transmitted by the imaging lens group is converged on the spectrum imaging chip structure on the sensor adapter plate;

the embedded information processing board is connected with the sensor adapter plate and is used for supplying power to the sensor adapter plate, interacting signals and processing and integrating image information of the sensor adapter plate;

the push-broom system is used for carrying the sensor adapter plate and the embedded information processing plate, and the push-broom system moves in the spectral dimension direction for push-broom;

the upper computer is respectively connected with the push-broom system and the embedded information processing board, and is used for controlling the mobile push-broom of the push-broom system and acquiring a complete spectrum image according to the integrated image information of the embedded information processing board.

52. The spectral imaging system of claim 47, wherein the narrow band filter (20) of any one of the spectral imaging chip structures has a film system structure of H (LH) ≡S2nl (HL) ≡ S H, n is a film thickness adjusting coefficient, S is a number of times of superposition, H is a high refractive index material, L is a low refractive index material, the film thickness adjusting coefficients n of the four spectral imaging chip structures are all different, and the film thickness adjusting coefficients n are divided into corresponding spectral segments.

53. The spectral imaging system of claim 52, wherein the range of values of the film thickness adjustment coefficients n corresponding to the four spectral imaging chip structures is sequentially from 0.745 to 1.557, from 0.67 to 1.439, from 0.643 to 1.425, and from 0.652 to 1.437 in the spectral dimension.

54. A method of manufacturing a spectral imaging system, wherein the spectral imaging system is the spectral imaging system of claim 13 or 14, the method comprising:

dividing a pixel photosensitive unit (10) into a plurality of pixel areas along the direction of a spectrum dimension in sequence;

and secondly, sequentially and respectively integrally depositing and growing a plurality of spectrum imaging units on the pixel areas, wherein the spectrum imaging units are used for realizing narrow-band filtering, and the spectrum imaging units respectively cover different spectrum ranges.

55. The method of claim 54, wherein the second step comprises:

2.1, depositing a removing layer on the whole pixel area of the pixel photosensitive unit;

2.2, preparing a first spectral imaging unit along a spectral dimension direction, comprising:

2.21, removing the removing layer on the first pixel area corresponding to the first spectrum imaging unit;

2.22 preparing a first spectral imaging unit on the structure obtained in step 2.21 based on the raw material of the first spectral imaging unit;

2.3, removing the redundant removing layer, and integrally depositing the removing layer on the structure obtained in the step 2.2;

2.4, preparing a second spectral imaging unit along the spectral dimension, comprising:

2.41, removing the removing layer on the second pixel area corresponding to the second spectrum imaging unit;

2.42 preparing a second spectral imaging unit on the structure obtained in step 2.41 based on the starting material of the second spectral imaging unit;

2.5, and the like, adopting the same process as the steps 2.3-2.4 to sequentially prepare the rest spectrum imaging units.

56. An imaging method of a line scan spectral imaging system, wherein the imaging method of the line scan spectral imaging system uses the line scan spectral imaging system of claims 47 to 51 for spectral imaging, the imaging method of the line scan spectral imaging system comprising:

the upper computer controls the push-broom system to move along the direction of the spectrum dimension according to the preset push-broom speed;

after the moving speed of the push-broom system is stable, the embedded information processing board acquires at least one spectrum imaging chip structure image at a preset frame rate, integrates the images and uploads the images to the upper computer;

And the upper computer extracts a specific spectrum part in each frame of image and splices the specific spectrum part to acquire a complete spectrum image of the spectrum part in a scanning range.

57. An imaging method of a line scan spectral imaging system as recited in claim 56, wherein said predetermined push-broom speed satisfies V _min ≥L/f _frame Wherein V is _min For a minimum preset push-broom speed of the push-broom system, L is the length of the FP cavity step width mapped onto the imaging object plane, L/l=d/f _focus =2tan θ, l is the step width, D is the distance from the optical center of the imaging lens set to the object plane, f _focus For the focal length of the imaging lens group, θ is the angle of view of the imaging lens group, f _frame Is the image frame rate.