CN114295207A - Uncooled hyperspectral imaging chip and hyperspectral imager - Google Patents
Uncooled hyperspectral imaging chip and hyperspectral imager Download PDFInfo
- Publication number
- CN114295207A CN114295207A CN202111641467.0A CN202111641467A CN114295207A CN 114295207 A CN114295207 A CN 114295207A CN 202111641467 A CN202111641467 A CN 202111641467A CN 114295207 A CN114295207 A CN 114295207A
- Authority
- CN
- China
- Prior art keywords
- spectrum
- hyperspectral
- uncooled
- pixel
- spectral
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The application discloses an uncooled hyperspectral imaging chip and a hyperspectral imager, which comprise an imaging photosensitive chip, wherein the imaging photosensitive chip comprises a plurality of linear pixel arrays which are arranged in a preset direction; each linear pixel array comprises a plurality of identical spectrum pixels, the spectrum pixels in different linear pixel arrays are different, and each spectrum pixel comprises a plurality of characteristic microstructures which enable the spectrum response of the spectrum pixel to be broadband response; the imaging photosensitive chip obtains spectral information and spatial information of the target to be detected when moving in the preset direction, and a hyperspectral image of the target to be detected is obtained. The characteristic microstructure enables the spectral response of the hyperspectral imaging chip to be broadband, and improves luminous flux and signal-to-noise ratio; and because the broadband response spectrum pixel is used, the line scanning flexibility is increased, and the acquisition speed of the hyperspectral image can be improved.
Description
Technical Field
The application relates to the field of hyperspectral imaging, in particular to an uncooled hyperspectral imaging chip and a hyperspectral imager.
Background
The hyperspectral imaging technology is characterized in that a hyperspectral imager is used for continuously imaging a target object in dozens or hundreds of spectral wave bands in a spectral coverage range, and spectral information of the target object is obtained while spatial characteristic imaging of the target object is obtained.
At present, when a hyperspectral imager carries out hyperspectral imaging, the following modes are available: firstly, a Fourier transform and grating light splitting method is combined with a scanning system with a mechanical moving part, and long-wave infrared hyperspectral imaging is realized in a push-scanning or swing-scanning mode, the scanning speed is low, the structure is complex, in addition, a complex light path needs to be designed, the size is large, the cost is high, and the slit enables the luminous flux and the signal-to-noise ratio of the imaging system to be low; secondly, a linear gradient filter is arranged outside the detector array to realize light splitting, scene replication is realized by utilizing a micro-lens array, infrared hyperspectral imaging is realized, the process of the gradient filter is complex, the yield is reduced by a mode of mounting the gradient filter, and the spatial resolution is greatly reduced by the micro-lens array; thirdly, a Fabry-Perot narrow-band filter structure is arranged on the photosensitive layer of the pixel to realize light splitting, so that the imaging system of the hyperspectral imager has small luminous flux and low signal-to-noise ratio.
Therefore, how to solve the above problems should be a great concern to those skilled in the art.
Disclosure of Invention
The application aims to provide an uncooled hyperspectral imaging chip and a hyperspectral imager so as to improve the spatial resolution, luminous flux and signal-to-noise ratio of a hyperspectral image and improve the acquisition speed of the hyperspectral image.
In order to solve the technical problem, the application provides an uncooled hyperspectral imaging chip, which comprises an imaging photosensitive chip, wherein the imaging photosensitive chip comprises a plurality of linear pixel arrays which are arranged in a preset direction;
each linear pixel array comprises a plurality of identical spectrum pixels, the spectrum pixels in different linear pixel arrays are different, and each spectrum pixel comprises a plurality of characteristic microstructures which enable the spectrum response of the spectrum pixel to be broadband response; and the imaging photosensitive chip acquires the spectral information and the spatial information of the target to be detected when moving in the preset direction, and a hyperspectral image of the target to be detected is obtained.
Optionally, in a direction perpendicular to the preset direction, the number of the spectrum pixels in the linear pixel array is equal to the number of the detector pixels.
Optionally, a plurality of spectrum pixels in each linear pixel array are arranged in a single row.
Optionally, a plurality of spectrum pixels in each linear pixel array are arranged in multiple rows.
Optionally, the characteristic microstructure is a photonic crystal or a plasmon structure or a multilayer thin film stacked structure, wherein when the characteristic microstructure is a photonic crystal or a plasmon structure, at least one of the shape, the size, the distribution period, and the arrangement form of the characteristic microstructure in different spectral pixels is different; when the characteristic microstructure is a multilayer film laminated structure, the refractive indexes of the multilayer films are arranged at intervals.
Optionally, the method further includes:
and the protective layer is positioned on the upper surface of the characteristic microstructure.
Optionally, when the feature microstructure is a photonic crystal, the feature microstructure is a through hole, and the feature microstructure is located on a second supporting layer in a second suspended pixel structure of the spectrum pixel.
Optionally, the arrangement form of the characteristic microstructures in each spectral pixel is any one of a tetragonal lattice arrangement, a hexagonal lattice arrangement, a random arrangement and a mixed arrangement.
Optionally, the spectrum pixels in the linear pixel array are arranged according to a preset rule, where the preset rule is that a pearson correlation coefficient between a response spectrum of the spectrum pixel in each linear pixel array and a response spectrum of the spectrum pixel in an adjacent linear pixel array is less than 0.5.
The application also provides a hyperspectral imager, including:
the non-refrigeration hyperspectral imaging chip comprises a chip body and a chip body, wherein the chip body is provided with a light source;
the displacement table is used for driving the non-refrigeration hyperspectral imaging chip to move along a preset direction;
an imaging lens.
The non-refrigeration hyperspectral imaging chip comprises an imaging photosensitive chip, wherein the imaging photosensitive chip comprises a plurality of linear pixel arrays which are arranged in a preset direction; each linear pixel array comprises a plurality of identical spectrum pixels, the spectrum pixels in different linear pixel arrays are different, and each spectrum pixel comprises a plurality of characteristic microstructures which enable the spectrum response of the spectrum pixel to be broadband response; and the imaging photosensitive chip acquires the spectral information and the spatial information of the target to be detected when moving in the preset direction, and a hyperspectral image of the target to be detected is obtained.
Therefore, the imaging photosensitive chip in the uncooled hyperspectral imaging chip in the application comprises a plurality of linear pixel arrays which are distributed in the preset direction, so that the uncooled hyperspectral imaging chip can scan the target to be detected when moving in the preset direction, and the spatial information of the target to be detected is obtained; the linear pixel array comprises a plurality of identical spectrum pixels, and the spectrum pixels in different linear pixel arrays are different, so that in the scanning process, the combination formed by any one spectrum pixel in the linear pixel array and the spectrum pixels at the same positions in other linear pixel arrays can measure the spectrum information of the corresponding area of the object to be measured, and the hyperspectral image of the target to be measured under the wavelength can be obtained by integrating all the spectrum information and extracting the intensity information under the corresponding wavelength channel. The spectrum pixel comprises a plurality of characteristic microstructures which enable the spectrum response of the spectrum pixel to be broadband response, namely the spectrum response of the uncooled hyperspectral imaging chip is broadband, and luminous flux and signal-to-noise ratio are improved; meanwhile, the uncooled hyperspectral imaging chip does not need to attach an optical filter outside a detector window, the yield and the integration level are improved, the spatial resolution is not lost in a line scanning mode, and a hyperspectral image with high resolution can be obtained; and because the broadband response spectrum pixel is used, the line scanning flexibility is increased, and the acquisition speed of the hyperspectral image can be improved.
In addition, this application still provides a hyperspectral imager.
Drawings
For a clearer explanation of the embodiments or technical solutions of the prior art of the present application, the drawings needed for the description of the embodiments or prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a top view of a hyperspectral imaging chip provided in an embodiment of the application;
FIG. 2 is a top view of another hyperspectral imaging chip provided by an embodiment of the application;
FIG. 3 is a schematic structural diagram of a spectrum pixel provided in an embodiment of the present application;
fig. 4 to 7 are schematic views illustrating an arrangement of feature microstructures provided in an embodiment of the present application;
FIG. 8 is a schematic structural diagram of another spectral pixel provided in an embodiment of the present application;
FIG. 9 is a top view of an uncooled hyperspectral imaging chip corresponding to FIG. 8;
FIG. 10 is a partial spectral pixel response spectrum of FIG. 8;
FIG. 11 is a schematic structural diagram of another spectral pixel provided in an embodiment of the present application;
FIG. 12 is a top view of an uncooled hyperspectral imaging chip corresponding to FIG. 11;
FIG. 13 is a diagram illustrating a manner of acquiring data by a non-refrigeration hyperspectral imaging chip in a line scan according to an embodiment of the application;
FIGS. 14 and 15 are schematic diagrams of different line scanning modes of an uncooled hyperspectral imaging chip according to an embodiment of the application;
FIG. 16 is a data processing flow chart of the uncooled hyperspectral imaging chip acquiring the hyperspectral data cube and the hyperspectral image according to the application;
FIG. 17 is a top view of an uncooled hyperspectral imaging chip in example 1 of the application;
FIG. 18 is a response spectrum of a part of spectral pixels in the uncooled hyperspectral imaging chip in FIG. 17;
FIG. 19 is a diagram illustrating a manner in which the uncooled hyperspectral imaging chip in FIG. 17 acquires data by line scanning;
FIG. 20 is a top view of an uncooled hyperspectral imaging chip in example 2 of the application;
FIG. 21 is a diagram illustrating a manner in which the uncooled hyperspectral imaging chip in FIG. 20 acquires data by line scanning;
fig. 22 is a schematic diagram of a hyperspectral imager for line scanning hyperspectral imaging of a target to be measured according to the present application.
Detailed Description
In order that those skilled in the art will better understand the disclosure, the following detailed description will be given with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.
As described in the background section, various methods adopted in the hyperspectral imaging currently have certain defects, for example, a traditional hyperspectral imaging system needs to be combined with a large-scale scanning system to realize hyperspectral imaging in a push-scanning or sweep-scanning manner, the scanning speed is slow, and a plurality of optical lenses need to be arranged, so that the volume is large; the mode of attaching the linear gradient filter or the narrow-band filter outside the window of the infrared detector has higher requirement on alignment precision and lower integration level, and the light splitting principle based on the narrow-band filter also causes low luminous flux and signal-to-noise ratio.
In view of this, the present application provides an uncooled hyperspectral imaging chip, please refer to fig. 1 and fig. 2, which includes an imaging photosensitive chip, where the imaging photosensitive chip includes a plurality of linear pixel arrays S arranged in a preset direction;
each linear pixel array S comprises a plurality of identical spectrum pixels A, the spectrum pixels A in different linear pixel arrays S are different, and each spectrum pixel A comprises a plurality of characteristic microstructures B which enable the spectrum response of the spectrum pixel A to be broadband response; and the imaging photosensitive chip acquires the spectral information and the spatial information of the target to be detected when moving in the preset direction, and a hyperspectral image of the target to be detected is obtained.
The preset direction is not limited in the present application, and may be either the Y direction in the paper surface or the X direction in the paper surface. It is emphasized that the line-shaped pixel array S and the line scanning movement direction (the preset direction) are perpendicular regardless of whether the preset direction is the X direction or the Y direction.
In the present application, the number of rows of the spectrum pixels a in the linear pixel array S is not limited, for example, a plurality of the spectrum pixels a in each linear pixel array S are arranged in a single row, as shown in fig. 1, or a plurality of the spectrum pixels a in each linear pixel array S are arranged in a plurality of rows r (r >1), as shown in fig. 2. Further, the number of spectral pixels a in each linear pixel array S is not limited in this application, as the case may be. In fig. 1 and 2, the number of each line of spectral pixels a in the linear pixel array S is m, and the number of the linear pixel array S is n. The predetermined direction in fig. 1 and 2 is taken as an example of the Y direction.
Combination of any spectrum pixel A in linear pixel array S and spectrum pixels A at same positions in other linear pixel arrays S, such as spectrum pixel A in FIG. 11(1)、A2(1)、…、An(1) Or A is1(m)、A2(m)、…、An(m) can be regarded as a micro spectrometer, and realizes the region I with the abscissa of j and the ordinate of k in the target image to be measuredj,kAnd (j is 1,2 … m, k is 1,2 … i), integrating all the regions to realize the spectral measurement of the target to be measured, and combining the intensity and the spectral information of m regions by i to obtain the hyperspectral data cube.
The structure schematic diagram of the spectrum pixel A is shown in fig. 3, and comprises a base layer, a first suspended pixel structure and a second suspended pixel structure which are overlapped from bottom to top, wherein the base layer comprises a substrate 2 containing a reading circuit, a metal reflecting layer 3 and a second electrode layer 4 which are positioned on the upper surface of the substrate 2, and an insulating medium layer 5 which is positioned on the upper surface of the metal reflecting layer 3 and the upper surface of the second electrode layer 4; the first suspended pixel structure comprises a first supporting layer 6 with a first through hole, a first electrode layer 7, a thermosensitive layer 8, a thermosensitive protective layer 9 and a supporting and electric connecting hole 10, wherein the first through hole is positioned at the bottom of the supporting and electric connecting hole 10 so that the first electrode layer 7 is electrically connected with the second electrode layer 4; the second suspended pixel structure comprises a micro-structure layer 1 formed by a plurality of characteristic micro-structures B, a supporting connection hole 11 and a second supporting layer 12, wherein the second supporting layer 12 positioned at the supporting connection hole 11 is connected with the thermosensitive protection layer 9, the supporting connection hole 11 is positioned at the outer side or the inner side of the supporting and electric connection hole 10, and the micro-structure layer 1 is positioned on the upper surface of the second supporting layer 12. The material of the second support layer 12 may be silicon nitride, silicon oxide, silicon oxynitride, or the like, and the thickness may be 50nm to 300 nm.
And when the spectral responses of the spectral pixels A are the same, the spectral pixels A are considered to be the same spectral pixel A. The characteristic microstructures B in each spectrum pixel A are arranged in a certain periodic array, and the arrangement form of the characteristic microstructures B in each spectrum pixel A includes but is not limited to any one of tetragonal lattice arrangement, hexagonal lattice arrangement, random arrangement and mixed arrangement. Schematic diagrams of the tetragonal lattice arrangement, the hexagonal lattice arrangement, the random arrangement and the mixed arrangement of the characteristic microstructure B are respectively shown in fig. 4 to 7. The hexagonal lattice arrangement enables the characteristic microstructure B in each spectrum pixel A to be denser, the response to be stronger and the signal-to-noise ratio during spectrum measurement to be higher. The random arrangement makes the response spectrum of the spectral pixel A less sensitive to polarization. The mixed arrangement enables the response spectrums of the spectrum pixels A to be more random, the correlation coefficient between the response spectrums of different spectrum pixels A is smaller, and the precision is higher when the spectrum is measured.
Different spectral pixel elements A comprise different characteristic microstructures B, and the broadband response of the different spectral pixel elements A is different due to the difference of the characteristic microstructures B. The shape and size of the characteristic microstructure B in different spectrum pixel elements A are different, the shape of the characteristic microstructure B comprises but is not limited to a cylindrical structure, a square structure, a triangular column shape, a hollow cylindrical shape, a hollow square shape and a hollow triangular column shape, and the detailed characteristic parameters, the material parameters, the array arrangement period and the structure parameters are designed and optimized based on the results of numerical calculation simulation and combined with judgment indexes such as correlation coefficients, spectrum reconstruction quality and the like, and are further confirmed and adjusted through experiments. The different spectral pixels A produce different modulation effects including, but not limited to, scattering, absorption, transmission, reflection, interference, etc. for different wavelengths of incident light.
It should be noted that the type of the characteristic microstructure B is not limited in this application, and may be set by itself. For example, the characteristic microstructure B includes, but is not limited to, a photonic crystal or a plasmonic structure or a multilayer thin film laminated structure, wherein, when the characteristic microstructure B is a photonic crystal or a plasmonic structure, at least one of the shape, size, distribution period, and arrangement form of the characteristic microstructure B in different spectral pixels a is different; when the characteristic microstructure B is a multilayer film laminated structure, the refractive indexes of the multilayer films are arranged at intervals.
Plasmonic structures (Surface plasmons) are electromagnetic oscillations formed by the interaction of a free electron and a photon in a metal Surface region, using the interaction between Surface charge oscillations and the electromagnetic field of light waves to modulate the incident light field. When the feature microstructure B is a plasmon structure, the material of the microstructure layer 1 is a metal material, for example, any one or any combination of gold, silver, copper, platinum, titanium, chromium, and aluminum. The thickness of the microstructure layer 1 may be between 10nm and 200 nm.
The photonic crystal is an artificial microstructure formed by periodically arranging media with different refractive indexes. From a material structure perspective, photonic crystals are a class of artificially designed and fabricated crystals with periodic dielectric structures on the optical scale. The photonic crystal has a wavelength selection function, and can selectively allow light of a certain wavelength band to pass through and prevent light of other wavelengths from passing through. When the feature microstructure B is a photonic crystal, the feature microstructure B may be located on the upper surface of the second support layer 12 in the form of a microstructure layer 1, preferably, in an embodiment of the present application, in order to simplify the process, when the feature microstructure B is a photonic crystal, the feature microstructure B is a through hole, the feature microstructure B is located on the second support layer in the second suspended pixel structure of the spectrum pixel a, at this time, a schematic structure diagram of the spectrum pixel a is shown in fig. 8, a top view of the hyperspectral imaging chip is shown in fig. 9, wherein the number of the linear pixel arrays S is 1024, each linear pixel array S includes four rows of spectrum pixels a, each row includes 1280 spectrum pixels a, a response spectrum of a part of the spectrum pixels a is shown in fig. 10, wherein the abscissa is a wavelength, and the ordinate is a relative response.
When the feature microstructure B is a photonic crystal or a plasmon structure, it should be noted that the size of the feature microstructure B is not limited in this application, for example, the size of the feature microstructure B may be 300nm to 3000 nm. The distribution period of the characteristic microstructures B, that is, the pitch of the characteristic microstructures B, may be 1 μm to 4 μm, and is not specifically limited in this application.
When the feature microstructure B is a multilayer film stack structure, the fold for each layer of film 14The refractive index is not limited as long as the refractive indexes of the plurality of thin films 14 are arranged at intervals, that is, the refractive indexes of two adjacent thin films 14 are different. The number of the multilayer film 14 is 3-10 layers, and the specific number of the layers can be set by self. The thickness of the film 14 may be between 50nm and 2000nm, and the thickness of each layer of film 14 may be equal or unequal. The material of the thin film in this application is a dielectric material, and the specific kind is not limited, for example, the material of each layer of thin film 14 can be ZnS, Ge, Si, SiO2SiN, etc. By controlling the material and thickness of each layer of film 14, a variety of morphologic response spectra can be produced. When the characteristic microstructure B is a multilayer film laminated structure, the structural schematic diagram of the spectrum pixel A is shown in FIG. 11, and the top view of the uncooled hyperspectral imaging chip is shown in FIG. 12. Response spectra of various morphologies can be generated by controlling the material and thickness of the film.
When the characteristic microstructure B is a multilayer film laminated structure, the multilayer film laminated structure is different in different first spectrum pixel elements A. In the present application, the multilayer thin film stack structure is distinguished according to the thickness of the thin film, i.e. when the thickness of the thin film in the multilayer thin film stack structure is different, the first spectral pixel a is a different spectral pixel. It should be noted that, in the multilayer thin film lamination structure of different first spectrum pixel elements a, the thin film materials may be the same or different.
In the direction perpendicular to the preset direction, the number of the spectrum pixels a in the linear pixel array S is equal to the number of the detector pixels, that is, one spectrum pixel a includes one detector pixel.
Preferably, the spectral pixel a further comprises: and the protective layer is positioned on the upper surface of the characteristic microstructure B to protect the characteristic microstructure B, and the protective layer 13 is made of dielectric materials such as silicon nitride, silicon oxide, silicon oxynitride and the like and has a thickness of 10 nm-300 nm.
The process of measuring the hyperspectral image of the target to be measured by using the uncooled hyperspectral imaging chip is introduced below, and the hyperspectral image is comprehensively realized based on the line scanning, calibration data and a spectrum reconstruction algorithm of the uncooled hyperspectral imaging chip.
Line scanning non-refrigerationThe manner in which the hyperspectral imaging chip acquires data is shown in fig. 13. The infrared uncooled hyperspectral imaging chip 15 shown in fig. 1 scans a target image 17' to be measured under the control of a precision displacement table, and the moving step length of each frame is d (d)>1) spectral pixels a. From n linear pixel array S in non-refrigeration hyperspectral imaging chipnStarting to scan the target image 17' to be measured to the last linear pixel array S1Finishing scanning the target image to be detected 17', and scanning n + i-2 steps in total to obtain a target image to be detected with the image resolution of m x i; for the area I with the abscissa of j and the ordinate of k in the target image to be detectedj,k(j is 1,2 … m, k is 1,2 … I), a micro spectrometer 21 formed by n spectrum pixels A and formed along the moving direction of the uncooled hyperspectral imaging chip 15 is arranged in the process of line scanning, and the aim of I pair is achievedj,kAnd (4) performing spectral measurement on the regions, and integrating all the regions to realize spectral measurement on the target image to be measured. And combining the intensity and the spectrum information of the m regions, namely the hyperspectral data cube 21 can be obtained.
The image can be seen to be composed of a plurality of location points, each location point having a corresponding intensity, and the spatial information is indicative of the location of each location point in the image. The linear pixel array can obtain the position information of the corresponding area of the target to be measured in the scanning process, and the spatial information of the whole target to be measured can be obtained after the scanning is finished.
In the present application, the line scanning manner of the uncooled hyperspectral imaging chip is not limited, for example, all the line pixel arrays S in the uncooled hyperspectral imaging chip scan the whole target image to be measured, as shown in fig. 14, from the line pixel array S1Scanning to the linear pixel array SnOr, scanning is performed with a part of the line-shaped pixel array S, as shown in FIG. 15, from the line-shaped pixel array SpScanning to the linear pixel array SqAnd the difference value of p and q is less than the total number n of the linear pixel array S. Only part of the linear pixel array S is used for scanning, so that the rate of acquiring a hyperspectral data cube can be increased, the time resolution of hyperspectral imaging is increased, and the detection capability of a dynamic target to be detected can be enhanced; high spectral composition in line scan using narrowband filtersIn the technical scheme, if only a part of the array is used for scanning, the spectral information of the unscanned part of the waveband is lost, but although the technical scheme of the application only uses a part of the linear pixel array S, the lack of the spectral waveband can be avoided through an algorithm.
The process of measuring the spectrum of the target image to be measured is as follows: calibration data of the uncooled hyperspectral imaging chip are obtained in advance through experiments, and the experimental calibration method includes but is not limited to wavelength scanning measurement and infrared wavelength tunable laser scanning measurement by using a Fourier transform infrared spectrometer, a black body light source and a monochromator. The calibration data refers to wavelength discretization (lambda) in the uncooled hyperspectral imaging chip1、λ2…、λj、…λM) N linear pixel array Si(S1、S2…、Si、…、Sn) And a spectral response matrix H formed in the moving direction of the uncooled hyperspectral imaging chip. In the scanning process, a micro spectrometer is formed by combining any spectrum pixel in the linear pixel array and spectrum pixels at the same position in other linear pixel arrays, and spectrum information of a corresponding area of a target to be measured can be measured. Construction of region I in target image 17' to be measured based on calibration dataj,k(j-1, 2 … m; k-1, 2 … i) as Yj,k＝H*Ij,k+ ε, wherein Yj,kRepresenting the region I in the target image 17' to be measuredj,kThe spectrum information is input into the intensity output signal of the micro spectrometer; h represents a spectral response matrix of a micro spectrometer in the uncooled hyperspectral imaging chip; ε represents the noise during the measurement. Writing the above mathematical model in the form of a matrix, including:
wherein h isi(λj) Representing the response of the ith spectrum pixel A in the micro spectrometer to the discretized jth wavelength; y isj,kY in (1)q(q-1, 2, …, t, …, n) denotes measurement Ij,kIntensity response, Y, of the qth spectral pixel of a regional-spectrum micro spectrometerj,kMiddle ynN is the number of the linear pixel arrays; i isj,kAnd expressing the area with the abscissa of j and the ordinate of k in the target image to be measured.
A data processing flow chart of the uncooled hyperspectral imaging chip for acquiring the hyperspectral data cube and the hyperspectral image is shown in fig. 16. The uncooled hyperspectral imaging chip scans the area of the target image to be detected, and the micro spectrometer formed along the moving direction can realize the purpose of scanning any area I in the target image to be detectedj,kThe spectral measurement of (2). Combining a spectral response matrix H of a micro spectrometer in an uncooled hyperspectral imaging chip calibrated in advance through experiments and a spectrum sparse representation dictionary psi obtained by adopting a dictionary learning algorithm, and solving an m x i individual matrix equation Y through a reconstruction algorithmj,k＝H*Ψ*αj,k+ ε, wherein Ij,k＝Ψ*αj,k，αj,kTo represent the dictionary Ψ pair I by using sparsenessj,kAnd sparsely representing the sparse matrix. When m x I regions of the spectrum (I) are obtained1，I2，…，Im*i) Then, the same wavelength lambda is respectively taken from the m x i spectral curvesj(λ1，λ2，…，λj，…，λM) And (4) processing the intensity value to form a hyperspectral image of the target to be measured in the jth spectral channel with the spatial resolution of M x i, and finally forming a hyperspectral data cube with M x i x M dimensions. Dictionary learning algorithms include, but are not limited to, KSVD (K-means Singular Value Decomposition), MOD (Method of Optimal Direction) algorithms; the solving algorithm includes, but is not limited to, least squares, convex optimization, greedy, bayesian.
According to the application, the imaging photosensitive chip in the uncooled hyperspectral imaging chip comprises a plurality of linear pixel arrays S which are distributed in the preset direction, so that the uncooled hyperspectral imaging chip can scan a target to be detected when moving in the preset direction, and spatial information of the target to be detected is obtained; the linear pixel array S comprises a plurality of identical spectrum pixels A, and the spectrum pixels A in different linear pixel arrays S are different, so that the linear pixel array is in the scanning processThe combination formed by any spectrum pixel A in the column S and the spectrum pixels A at the same positions in other linear pixel arrays S is a micro spectrometer, and any area I in a target image to be measured can be realizedj,kThe hyperspectral data cube can be obtained by combining the intensity and spectral information of all the areas. The spectrum pixel A comprises a plurality of characteristic microstructures B which enable the spectrum response of the spectrum pixel A to be broadband response, namely the spectrum response of the uncooled hyperspectral imaging chip is broadband, no slit or narrow-band filter is used for limiting the luminous flux of the spectrum imaging system, and the luminous flux and the signal-to-noise ratio are improved; meanwhile, the uncooled hyperspectral imaging chip does not need to attach an optical filter outside a detector window, the yield and the integration level are improved, the spatial resolution is not lost in a line scanning mode, and a high-resolution hyperspectral image can be obtained; and because the broadband response spectrum pixel is used, the line scanning flexibility is increased, and the acquisition speed of the hyperspectral image can be improved.
On the basis of any one of the above embodiments, in an embodiment of the present application, the spectrum pixels a in the linear pixel array S are arranged according to a preset rule, where the preset rule is that a pearson correlation coefficient between a response spectrum of the spectrum pixel a in each linear pixel array S and a response spectrum of the spectrum pixel a in an adjacent linear pixel array S is less than 0.5.
The calculation formula of the Pearson correlation coefficient is as follows:
wherein r is the Pearson correlation coefficient, Ti，TjThe response spectrums in the spectral response wave bands of the ith spectral pixel A and the j th spectral pixel A are respectively, and M is the dimension of i and j. The real correlation exists when the Pearson correlation coefficient is between 0 and +/-0.50, the obvious correlation exists when the Pearson correlation coefficient is higher than +/-0.50, and the high correlation exists when the Pearson correlation coefficient is higher than +/-0.8. The spectral response of the spectral pixel A is infrared broadband response, the smaller the Pearson correlation coefficient r among response spectrums is, the better the Pearson correlation coefficient r is, the smaller the Pearson correlation coefficient r is, the more beneficial the improvement of the spectral accuracy obtained by final measurementAnd (4) sex. If the correlation coefficient is higher, the accuracy of the measured spectrum can be improved by increasing the number of different spectrum pixel elements A.
In other embodiments of the present application, the spectral pixels a in the linear pixel array S may also be arranged randomly.
The non-refrigeration hyperspectral imaging chip in the application is introduced in different structures.
Example 1
The top view of the uncooled hyperspectral imaging chip is shown in fig. 17, the characteristic microstructure is a plasma laser structure, the infrared detector array is based on 1280 x 1024, and each linear pixel array SiThe spectrum is composed of 1 x 1280 same spectrum pixels, the response spectrum of partial spectrum pixels is shown in figure 18, the abscissa is wavelength, and the ordinate is relative response. As shown in fig. 19, the step length in the moving direction of the uncooled hyperspectral imaging chip 15 during line scanning is the distance of one spectrum pixel, and after 1022+ i scanning, a hyperspectral image with an image resolution of 1280 × i can be obtained, and a hyperspectral data cube 20 is obtained.
The spectrum pixel adopting the plasmon structure has the advantages that the spectrum response is insensitive to the angle and the polarization state of incident light, so that the spectrum pixel is favorable for acquiring more real and accurate spectrum information of a reconstructed target, is suitable for more complex scenes and reduces the calibration workload.
Example 2
The plan view of the uncooled hyperspectral imaging chip is shown in fig. 20, and the main difference between example 2 and example 1 is the linear pixel array SiAccording to the arrangement order of the adjacent linear pixel arrays SiAnd sequencing the correlation coefficients of the response of the optical spectrum pixels from left to right in turn from small to large until the whole area array is filled. The moving distance and the shooting frame number of the uncooled hyperspectral imaging chip can be effectively reduced, and therefore the time for acquiring the hyperspectral data cube is shortened.
The scanning mode of the uncooled hyperspectral imaging chip is shown in fig. 21, the step length in the moving direction of the uncooled hyperspectral imaging chip 15 during line scanning is the distance of one spectrum pixel, and due to the special arrangement sequence in the hyperspectral chip, the 1024 th type of hyperspectral imaging chip does not need to be used during line scanningLine-shaped pixel array S1024The target image 17' to be measured is scanned, and scanning is started from some linear pixel array in the middle (e.g. from S in this embodiment)4Start). After 2+ i steps, the whole target image 17' to be measured is scanned, the frame number is reduced to 2+ i frames, and the time resolution of hyperspectral imaging is greatly improved.
Example 3
The plan view of the uncooled hyperspectral imaging chip is shown in fig. 9, and the main difference between example 3 and example 1 is that the characteristic microstructure is a photonic crystal and is a through hole directly formed in the second support by etching. The spectrum pixel response spectrum is shown in fig. 10, compared with the spectrum pixel of the plasmon structure, the correlation coefficient is smaller, and the similar spectrum measurement precision can be realized by using fewer spectrum pixels. Therefore, the linear pixel array S in the uncooled hyperspectral imaging chipiThe optical spectrum pixel can be composed of 4 x 1280 same optical spectrum pixels, so that the types of the optical spectrum pixels are reduced, the luminous flux is obviously increased, and the signal-to-noise ratio and the dynamic range can be greatly improved.
The application also provides a hyperspectral imager, including:
the uncooled hyperspectral imaging chip 15 according to any of the embodiments;
the displacement table is used for driving the uncooled hyperspectral imaging chip 15 to move along a preset direction;
an imaging lens 16;
the uncooled hyperspectral imaging chip 15 comprises a photosensitive chip 151; a substrate 152 for carrying a photosensitive chip 151; and a package window 153 for packaging the photo sensor chip 151. The substrate 151 carries an integrated Circuit (ROIC).
A schematic diagram of line scanning hyperspectral imaging of a target to be measured 17 by using a hyperspectral imager in the application refers to fig. 22, the target to be measured 17 is imaged on an uncooled hyperspectral imaging chip 15 through an imaging lens 16, when an uncooled hyperspectral imaging chip 15 is driven by a precision displacement platform to move, the uncooled hyperspectral imaging chip 15 realizes scanning and shooting of the target to be measured image 17', space information of the target to be measured 17 can be obtained, and each linear pixel array S in the uncooled hyperspectral imaging chip 15 is subjected to uncooled hyperspectral imagingIn the process of moving and scanning the imaging chip 15, any one of the spectrum pixels forms a micro spectrometer with the spectrum pixels at the same position in other linear pixel arrays in the moving direction of the uncooled hyperspectral imaging chip 15, and any area I in a target image to be detected can be realizedj,kThe spectrum information 18 of the target 17 to be measured can be obtained by integrating the spectrum measurement results of all the regions. Respectively taking the same wavelength lambda from the spectral curves of all the regionsjThe intensity values can form a hyperspectral image 19 of the target to be measured in the jth spectral channel with the spatial resolution of M x i, and finally form a hyperspectral data cube with M x i x M dimensions.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
The non-refrigeration hyperspectral imager chip and the hyperspectral imager provided by the application are introduced in detail in the above. The principles and embodiments of the present application are explained herein using specific examples, which are provided only to help understand the method and the core idea of the present application. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.
Claims (10)
1. An uncooled hyperspectral imaging chip is characterized by comprising an imaging photosensitive chip, wherein the imaging photosensitive chip comprises a plurality of linear pixel arrays which are arranged in a preset direction;
each linear pixel array comprises a plurality of identical spectrum pixels, the spectrum pixels in different linear pixel arrays are different, and each spectrum pixel comprises a plurality of characteristic microstructures which enable the spectrum response of the spectrum pixel to be broadband response; and the imaging photosensitive chip acquires the spectral information and the spatial information of the target to be detected when moving in the preset direction, and a hyperspectral image of the target to be detected is obtained.
2. The uncooled hyperspectral imaging chip of claim 1, wherein the number of spectral pixels in the linear pixel array is equal to the number of detector pixels in a direction perpendicular to the preset direction.
3. The uncooled hyperspectral imaging chip according to claim 1, wherein a plurality of the spectral pixels in each of the linear pixel arrays are arranged in a single row.
4. The uncooled hyperspectral imaging chip according to claim 1, wherein a plurality of the spectral pixels in each linear pixel array are arranged in a plurality of rows.
5. The uncooled hyperspectral imaging chip according to claim 1, wherein the characteristic microstructure is a photonic crystal or a plasmonic structure or a multilayer thin film laminated structure, wherein when the characteristic microstructure is a photonic crystal or a plasmonic structure, at least one of the shape, the size, the distribution period and the arrangement form of the characteristic microstructure in different spectral pixels are different; when the characteristic microstructure is a multilayer film laminated structure, the refractive indexes of the multilayer films are arranged at intervals.
6. The uncooled hyperspectral imaging chip of claim 5, further comprising:
and the protective layer is positioned on the upper surface of the characteristic microstructure.
7. The uncooled hyperspectral imaging chip of claim 5, wherein when the feature microstructure is a photonic crystal, the feature microstructure is a through hole and the feature microstructure is located on a second support layer in a second suspended pixel structure of the spectral pixel.
8. The uncooled hyperspectral imaging chip according to claim 1, wherein the arrangement form of the characteristic microstructures in each spectral pixel is any one of a tetragonal lattice arrangement, a hexagonal lattice arrangement, a random arrangement and a mixed arrangement.
9. The uncooled hyperspectral imaging chip according to any one of claims 1 to 8, wherein the spectral pixels in the linear pixel array are arranged according to a preset rule, wherein the preset rule is that the Pearson correlation coefficient of the response spectrum of the spectral pixel in each linear pixel array and the response spectrum of the spectral pixel in the adjacent linear pixel array is less than 0.5.
10. A hyperspectral imager, comprising:
the uncooled hyperspectral imaging chip of any of claims 1 to 9;
the displacement table is used for driving the non-refrigeration hyperspectral imaging chip to move along a preset direction;
an imaging lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111641467.0A CN114295207A (en) | 2021-12-29 | 2021-12-29 | Uncooled hyperspectral imaging chip and hyperspectral imager |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111641467.0A CN114295207A (en) | 2021-12-29 | 2021-12-29 | Uncooled hyperspectral imaging chip and hyperspectral imager |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114295207A true CN114295207A (en) | 2022-04-08 |
Family
ID=80970659
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111641467.0A Pending CN114295207A (en) | 2021-12-29 | 2021-12-29 | Uncooled hyperspectral imaging chip and hyperspectral imager |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114295207A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104236714A (en) * | 2013-06-07 | 2014-12-24 | 刘红超 | Spectrum sensor for detecting strength of target waveband |
| CN206584063U (en) * | 2016-11-25 | 2017-10-24 | 湖南宏动光电有限公司 | A kind of light spectrum image-forming micro optical filter based on surface phasmon |
| CN207423363U (en) * | 2017-10-19 | 2018-05-29 | 中国科学院西安光学精密机械研究所 | A kind of minitype polarization light spectrum image-forming detection system |
| CN110132415A (en) * | 2019-05-29 | 2019-08-16 | 中国科学院长春光学精密机械与物理研究所 | Pixel grade multi-channel filter and the tunable video hyperspectral imager of pixel grade |
| CN110823374A (en) * | 2019-10-31 | 2020-02-21 | 中国科学院西安光学精密机械研究所 | Spectral imaging method and system for simultaneously obtaining high-space and high-spectral-resolution spectral images |
| CN111765972A (en) * | 2020-08-05 | 2020-10-13 | 广州星博科仪有限公司 | Portable hyperspectral imager based on pixel film coating technology and shooting method thereof |
| CN111896120A (en) * | 2020-08-11 | 2020-11-06 | 烟台睿创微纳技术股份有限公司 | Double-color polarization non-refrigeration infrared detector and manufacturing method thereof |
| CN113588085A (en) * | 2021-09-03 | 2021-11-02 | 杭州纳境科技有限公司 | Miniature snapshot type spectrometer |
| CN113670441A (en) * | 2021-08-11 | 2021-11-19 | 中国科学院光电技术研究所 | Long-wave infrared multispectral imaging device based on filter array and design method thereof |
-
2021
- 2021-12-29 CN CN202111641467.0A patent/CN114295207A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104236714A (en) * | 2013-06-07 | 2014-12-24 | 刘红超 | Spectrum sensor for detecting strength of target waveband |
| CN206584063U (en) * | 2016-11-25 | 2017-10-24 | 湖南宏动光电有限公司 | A kind of light spectrum image-forming micro optical filter based on surface phasmon |
| CN207423363U (en) * | 2017-10-19 | 2018-05-29 | 中国科学院西安光学精密机械研究所 | A kind of minitype polarization light spectrum image-forming detection system |
| CN110132415A (en) * | 2019-05-29 | 2019-08-16 | 中国科学院长春光学精密机械与物理研究所 | Pixel grade multi-channel filter and the tunable video hyperspectral imager of pixel grade |
| CN110823374A (en) * | 2019-10-31 | 2020-02-21 | 中国科学院西安光学精密机械研究所 | Spectral imaging method and system for simultaneously obtaining high-space and high-spectral-resolution spectral images |
| CN111765972A (en) * | 2020-08-05 | 2020-10-13 | 广州星博科仪有限公司 | Portable hyperspectral imager based on pixel film coating technology and shooting method thereof |
| CN111896120A (en) * | 2020-08-11 | 2020-11-06 | 烟台睿创微纳技术股份有限公司 | Double-color polarization non-refrigeration infrared detector and manufacturing method thereof |
| CN113670441A (en) * | 2021-08-11 | 2021-11-19 | 中国科学院光电技术研究所 | Long-wave infrared multispectral imaging device based on filter array and design method thereof |
| CN113588085A (en) * | 2021-09-03 | 2021-11-02 | 杭州纳境科技有限公司 | Miniature snapshot type spectrometer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11543653B2 (en) | Device components formed of geometric structures | |
| KR102031384B1 (en) | Solid-state imaging element and imaging system | |
| US9268144B2 (en) | Method for producing a mirror plate for Fabry-Perot interferometer, and a mirror plate produced by the method | |
| KR20200024097A (en) | Optical filter, optical filter system, spectrometer and method of fabrication thereof | |
| US20110049340A1 (en) | Wavelength spectroscopy device with integrated filters | |
| US20200066782A1 (en) | Device and method for multispectral imaging in the infrared | |
| CN113161376A (en) | Optical module and optical device using the same | |
| CN110023727B (en) | Miniaturized waveguide imaging spectrometer | |
| CN110146949A (en) | A kind of narrow-band spectrum filter structure and preparation method thereof | |
| US11719575B2 (en) | Transmission guided-mode resonant grating integrated spectroscopy device and method for manufacturing same | |
| US7330266B2 (en) | Stationary fourier transform spectrometer | |
| US20120200852A1 (en) | Spectroscopy and spectral imaging methods and apparatus | |
| CN113588085A (en) | Miniature snapshot type spectrometer | |
| WO2023045415A1 (en) | Spectral measurement device and method | |
| CN114323276B (en) | Uncooled hyperspectral imaging chip and hyperspectral imager | |
| WO2012088117A1 (en) | Spectrometer including three-dimensional photonic crystal | |
| CN211122509U (en) | Spectrometer structure and electronic equipment | |
| CN114295207A (en) | Uncooled hyperspectral imaging chip and hyperspectral imager | |
| WO2018011025A1 (en) | Lippmann-based waveguide spectrometer with planar waveguide chip | |
| CN112229515A (en) | Spectral analysis module and analysis method based on optical filter | |
| US20230417960A1 (en) | Color-routers for Image Sensing | |
| Somarapalli et al. | Realization of low-cost multichannel surface plasmon resonance based optical transducer | |
| CN113820013A (en) | Transmission type super-structure surface multispectral imager based on Fabry-Perot cavity | |
| CN114279565A (en) | Non-refrigeration infrared spectrum chip, preparation method thereof and infrared spectrometer | |
| CN112730267A (en) | Spectrometer structure and electronic equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |