Infrared thermoelectric spectral imaging system and infrared imaging method

Abstract

The embodiment of the present application provides an infrared thermoelectric spectral imaging system and an infrared imaging method, and the system comprises: an imaging lens and a thermoelectric detector, the thermoelectric detector comprises: an infrared window, a filter film, a modulation structure and a detector array, the imaging lens, the infrared window and the detector array are sequentially arranged along the optical axis direction of the imaging lens, the filter film is attached to the infrared window, and the modulation structure is located between the infrared window and the detector array. By arranging the filter film on the infrared window and arranging the modulation structure between the infrared window and the detector array, the detection performance of the thermoelectric detector is improved without changing the structure of the current thermoelectric detector, and high-precision measurement of the spectrum of the incident light from the outside world is realized.

Description

Technical Field

[0001] This invention relates to the field of spectral imaging technology, and in particular to an infrared thermoelectric spectral imaging system and infrared imaging method. Background Technology

[0002] A spectrometer is an instrument that obtains spectral information. Spectra carry a wealth of information and can be used for substance identification, detection, and analysis, finding wide application in fields such as agriculture, biology, chemistry, astronomy, medicine, environmental monitoring, and the semiconductor industry.

[0003] An infrared thermoelectric spectroscopy imaging system is an instrument that uses infrared radiation to obtain hyperspectral images of objects. The system receives external infrared radiation, encodes it through spectral modulation, and then the encoded radiation shines on a detector, generating heat. The thermosensitive material in the detector pixels absorbs this heat, causing changes in the electrical signal. A spectral inversion algorithm is then used to obtain the hyperspectral image based on these changes. Therefore, spectral modulation plays a crucial role in infrared thermoelectric spectroscopy imaging systems.

[0004] Visible light optoelectronic spectral imaging systems can directly stack the light modulation layer, sensing layer, and circuit layer onto the spectral imaging detector to achieve visible light spectrum modulation. However, applying this stacking method to thermoelectric detectors leads to a decrease in their detection performance. Therefore, applying the stacking method of visible light optoelectronic spectral imaging systems to infrared thermoelectric spectral imaging systems is not ideal. Consequently, a high-precision infrared thermoelectric spectral imaging system is needed. Summary of the Invention

[0005] This invention provides an infrared thermoelectric spectroscopy imaging system and method, which can at least achieve high-precision measurement of the spectrum of external incident light. The specific technical solution is as follows:

[0006] In a first aspect, embodiments of the present invention provide an infrared thermoelectric spectral imaging system, the system comprising: an imaging lens and a thermoelectric detector, the thermoelectric detector comprising: an infrared window, a filter film, a modulation structure, and a detector array, wherein:

[0007] The imaging lens, the infrared window, and the detector array are arranged sequentially along the optical axis of the imaging lens.

[0008] The filter film is attached to the infrared window, and the modulation structure is located between the infrared window and the detector array.

[0009] Optionally, the modulation structure is located on the side of the infrared window facing the detector array, and the filter film is attached to the other side of the infrared window.

[0010] Optionally, the filter film is attached to the side of the infrared window facing the imaging lens, and the modulation structure is located on the pixels of the detector array.

[0011] Optionally, the modulation structure is disposed on the pixels of the detector array via a thermally conductive layer.

[0012] Optionally, the modulation structure includes multiple modulation units, and each modulation unit includes multiple modulation subunits;

[0013] Each modulation subunit includes multiple identical modulation microstructures, which are uniformly distributed within the modulation subunit; the cross-sectional shapes of the modulation microstructures in different modulation subunits within the same modulation unit are different.

[0014] Optionally, the modulation microstructure is an infrared high-transmittance material modulation column, an infrared high-transmittance material modulation hole, or a metal modulation hole.

[0015] Optionally, the distance between the metasurface of the modulation microstructure and the pixels of the detector array is 10μm-2000μm.

[0016] Optionally, the height of the modulation microstructure is 2μm-10μm, the period of the modulation microstructure is 2μm-12μm, the number of periods of each modulation microstructure is 4-100, and the duty cycle of the modulation microstructure in each modulation subunit is 10%-90%.

[0017] Optionally, the space between the infrared window and the detector array is a vacuum environment.

[0018] Secondly, embodiments of the present invention provide an infrared imaging method, the method comprising:

[0019] Acquire a grayscale image corresponding to the target object, wherein the grayscale image is obtained by the infrared thermoelectric spectroscopy imaging system described in any of the first aspects above;

[0020] Based on the grayscale image, a hyperspectral image corresponding to the target object is generated using a spectral inversion algorithm.

[0021] Optionally, after the step of generating a hyperspectral image corresponding to the target object based on the grayscale image using a spectral inversion algorithm, the method includes:

[0022] Based on the hyperspectral image, the properties of the target object are determined, wherein the properties include physical properties and / or chemical properties.

[0023] Beneficial effects of the embodiments of the present invention:

[0024] In the solution provided by this invention, the infrared thermoelectric spectroscopy imaging system includes an imaging lens and a thermoelectric detector. The thermoelectric detector includes an infrared window, a filter film, a modulation structure, and a detector array. The imaging lens, infrared window, and detector array are arranged sequentially along the optical axis of the imaging lens. The filter film is attached to the infrared window, and the modulation structure is located between the infrared window and the detector array. In the above-mentioned infrared thermoelectric spectroscopy imaging system, by setting a filter film on the infrared window and setting the modulation structure between the infrared window and the detector array, the detection performance of the thermoelectric detector is improved without changing the current structural configuration of the thermoelectric detector, thereby achieving high-precision measurement of the spectrum of external incident light. Of course, implementing any product or method of this invention does not necessarily require achieving all the advantages described above simultaneously. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram of the structure of the first infrared thermoelectric spectroscopy imaging system provided in an embodiment of the present invention;

[0027] Figure 2 based on Figure 1 A schematic diagram of a specific structure of the vanadium oxide detector in the embodiment shown;

[0028] Figure 3 This is a schematic diagram of the structure of the second infrared thermoelectric spectroscopy imaging system provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the third infrared thermoelectric spectroscopy imaging system provided in the embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the structure of the fourth infrared thermoelectric spectroscopy imaging system provided in the embodiments of the present invention;

[0031] Figure 6 For based on Figure 1 A schematic diagram of a specific structure of the multifunctional spectral filter in the embodiment shown;

[0032] Figure 7 This is a schematic diagram of the structure of the fifth infrared thermoelectric spectroscopy imaging system provided in the embodiments of the present invention;

[0033] Figure 8This is a schematic diagram of the sixth infrared thermoelectric spectroscopy imaging system provided in an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of a modulation structure provided in an embodiment of the present invention;

[0035] Figure 10 for Figure 9 A schematic diagram of a modulation unit in the illustrated embodiment;

[0036] Figure 11 This is a schematic diagram of a metal modulation aperture provided in an embodiment of the present invention;

[0037] Figure 12 For based on Figure 1 A schematic diagram of the distance between the metasurface and the FPA in the illustrated embodiment;

[0038] Figure 13 This is a schematic diagram of a high-transmittance infrared material modulation column provided in an embodiment of the present invention;

[0039] Figure 14 This is a flowchart of an infrared imaging method provided in an embodiment of the present invention.

[0040] in, Figures 1-14 The correspondence between the component names and their corresponding reference numerals in the figures is as follows:

[0041] 110 Imaging lens, 120 Thermoelectric detector, 101 Infrared window, 102 Filter film, 103 Modulation structure, 104 Detector array, 201 Thermal insulation layer, 202 CMOS substrate, 203 Reflector, 204 Interconnect structure, 205 Readout circuit, 701 Thermal conductive layer, 1001 First modulation subunit, 1002 Second modulation subunit, 1003 Third modulation subunit, 1004 Fourth modulation subunit, 1301 Infrared high-transmittance material modulation column. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art based on the present invention are within the scope of protection of the present invention.

[0043] To achieve high-precision measurement of the spectrum of incident light from the outside, this invention provides an infrared thermoelectric spectroscopy imaging system and an infrared imaging method. The infrared thermoelectric spectroscopy imaging system provided by this invention will be introduced first.

[0044] like Figure 1 As shown, an infrared thermoelectric spectroscopy imaging system includes an imaging lens 110 and a thermoelectric detector 120. The thermoelectric detector 120 includes an infrared window 101, a filter film 102, a modulation structure 103, and a detector array 104, wherein:

[0045] The imaging lens 110, the infrared window 101, and the detector array 104 are arranged sequentially along the optical axis of the imaging lens 110.

[0046] The filter film 102 is attached to the infrared window 101, and the modulation structure 103 is located between the infrared window 101 and the detector array 104.

[0047] As can be seen, in the solution provided by the embodiments of the present invention, the infrared thermoelectric spectroscopy imaging system includes: an imaging lens and a thermoelectric detector. The thermoelectric detector includes: an infrared window, a filter film, a modulation structure, and a detector array. The imaging lens, the infrared window, and the detector array are arranged sequentially along the optical axis of the imaging lens. The filter film is attached to the infrared window, and the modulation structure is located between the infrared window and the detector array. In the above-mentioned infrared thermoelectric spectroscopy imaging system, by setting a filter film on the infrared window and setting the modulation structure between the infrared window and the detector array, the detection performance of the thermoelectric detector is improved without changing the current structural composition of the thermoelectric detector, thereby achieving high-precision measurement of the spectrum of external incident light.

[0048] The infrared thermoelectric spectroscopy imaging system provided in this embodiment of the invention may include: an imaging lens 110 and a thermoelectric detector 120. The thermoelectric detector 120 may include: an infrared window 101, a filter film 102, a modulation structure 103, a detector array 104, and a readout circuit. Figure 1 (Not shown in the image).

[0049] The imaging lens 110 can be a convex lens, allowing incident light to be focused onto the infrared window 101. Infrared light of a specific wavelength can penetrate the filter film 102, while incident light of other wavelengths cannot pass through it, thus filtering the incident light. For example, the filter film 102 can allow long-wave infrared radiation with wavelengths of 6μm to 14μm to pass through, achieving filtering of incident radiation of different wavelengths.

[0050] The aforementioned infrared window 101 can be made of a high-transmittance infrared material, such as silicon (Si), silicon dioxide (SiO2), germanium (Ge), zinc sulfide (ZnS), and ytterbium fluoride (Cas). Because these high-transmittance infrared materials have high transmittance and refractive index for infrared light, long-wave infrared radiation has high transmittance after incident on the material, and the angle of refraction is smaller than the angle of incidence. Therefore, the light loss rate of incident light passing through the high-transmittance infrared material is low, which can improve light utilization.

[0051] In infrared thermoelectric spectral imaging systems, the spectral modulation layer is sensitive to the incident angle. That is, the output spectral modulation curve is different after the incident light is incident on the spectral modulation layer at different angles. Therefore, in the process of spectral modulation, it is necessary to calibrate the modulation spectral curve at different imaging distances to reduce the impact caused by the huge difference in the incident angle of the incident light. However, the actual calibration process is quite complicated and wastes a lot of manpower.

[0052] In order to reduce the influence of the incident angle of incident light on spectral modulation, in one embodiment of the infrared thermoelectric spectral imaging system provided by the present invention, the modulation structure 103 can be disposed on the side facing the detector array 104. In this way, the difference in the incident angle of incident light can be reduced, so only the spectral modulation curve at a single imaging distance needs to be calibrated, reducing the complexity of the modulation spectral curve calibration and making the infrared thermoelectric spectral imaging system have better robustness.

[0053] The detector array 104 includes multiple detector imaging pixels. Each detector imaging pixel receives infrared radiation light modulated by the modulation structure 103. The thermosensitive material absorbs heat due to the irradiation of the infrared radiation light, thereby generating a change in the electrical signal. This converts the optical signal of the infrared radiation light into an electrical signal, and the readout circuit can then read the change in the electrical signal. Based on the change in the electrical signal, a hyperspectral image can be obtained by using a spectral inversion algorithm.

[0054] like Figure 2 As shown, taking a vanadium oxide detector as an example, the structure of a detector imaging pixel is described. The imaging pixel structure of a vanadium oxide (VOx) detector is generally a MEMS (Micro-Electro-Mechanical System) structure supported by double cantilever beams, including a thermally insulating layer 201, a CMOS (Complementary Metal-Oxide Semiconductor) substrate 202, a reflector 203, an interconnect structure 204, and a readout circuit 205.

[0055] The thermistor material is located on the central target surface of the vanadium oxide detector imaging pixel structure, used to receive external infrared radiation and heat. The thermal insulation layer 201 is made of silicon nitride (SiN). x It has a sandwich structure consisting of a vanadium oxide layer, a silicon nitride layer, and a silicon nitride layer. When the vanadium oxide layer in the thermal insulation layer 201 receives external infrared radiation, it generates heat, which in turn causes a change in electrical conductivity. The readout circuit 205 can then output the change in electrical signal.

[0056] In one embodiment of the present invention, in the infrared thermoelectric spectroscopy imaging system, the filter film 102 can be attached to the infrared window 101, and the modulation structure 103 is located between the infrared window 101 and the detector array 104. The filter film 102 can be attached to the infrared window 101 by means of vapor deposition, electroplating, or electrochemical deposition. For example, it can be electron beam deposition, magnetron sputtering deposition, PECVD (Plasma Enhanced Chemical Vapor Deposition) deposition, etc., and is not specifically limited herein.

[0057] Specifically, in one embodiment, the modulation structure 103 can be disposed on the infrared window 101, including two cases. In the first case, such as... Figure 1 As shown, the filter film 102 can be attached to the side of the infrared window 101 facing the imaging lens 110, and the modulation structure 103 can be located on the other side of the infrared window 101. That is, the existing infrared window 101 can be utilized, with the filter film 102 and the modulation structure 103 respectively placed on both sides of the infrared window 101. In this way, the small size, integration, and low cost of the infrared thermoelectric spectroscopy imaging system can be achieved without changing the current structure of the thermoelectric detector.

[0058] In the first case, such as Figure 3 As shown, the filter film 102 can be attached to the side of the infrared window 101 facing the detector array 104, and the modulation structure 103 is disposed on the filter film 102. Alternatively, the existing infrared window 101 can be used, with the filter film 102 and the modulation structure 103 disposed on the side of the infrared window 101 facing the detector array 104. In this way, a small size, integration, and low cost of the infrared thermoelectric spectroscopy imaging system can be achieved without changing the current structure of the thermoelectric detector.

[0059] In another embodiment, the modulation structure 103 can be disposed on the pixels of the detector array 104, including two cases. In the first case, such as... Figure 4As shown, the filter film 102 can be attached to the side of the infrared window 101 facing the imaging lens 110, and the modulation structure 103 is disposed on the pixels of the detector array 104. That is, the existing infrared window 101 and detector array 104 can be utilized, and the filter film 102 and modulation structure 103 can be disposed on the pixels of the infrared window 101 and detector array 104, respectively. In this way, the small size, integration, and low cost of the infrared thermoelectric spectroscopy imaging system can be achieved without changing the current structure of the thermoelectric detector.

[0060] In the second case, such as Figure 5 As shown, the filter film 102 can be attached to the side of the infrared window 101 facing the detector array 104, and the modulation structure 103 is disposed on the pixels of the detector array 104. That is, the existing infrared window 101 and detector array 104 can be utilized, and the filter film 102 and modulation structure 103 can be disposed on the pixels of the infrared window 101 and detector array 104, respectively. In this way, the small size, integration, and low cost of the infrared thermoelectric spectral imaging system can be achieved without changing the current structure of the thermoelectric detector.

[0061] In the case where the filter film 102 is attached to the side of the infrared window 101 facing the imaging lens 110, and the modulation structure 103 is located on the other side of the infrared window 101, the filter film 102, the infrared window 101, and the modulation structure 103 can form a multifunctional spectral filter.

[0062] In one implementation, such as Figure 6 As shown, the aforementioned multifunctional spectral filter may include a filter film 102, an infrared window 101, and a modulation structure 103. Taking the infrared window 101 as Si as an example, Si has a refractive index of 3.4699 for infrared light with a wavelength of 10 μm. When the infrared incident light passes through the filter film 102 at an incident angle of α = 60°, it enters the modulation structure 103 at a refraction angle of β = 14.45°. The modulation structure 103 can then modulate the long-wavelength infrared radiation. Thus, the multifunctional spectral filter can achieve both filtering and spectral modulation functions.

[0063] As can be seen, the filter film, infrared window, and modulation structure can form a multifunctional spectral filter. Without changing the structural composition of the infrared thermoelectric spectral imaging system, the infrared thermoelectric spectral imaging system includes a multifunctional spectral filter. Through this multifunctional filter, filtering and spectral modulation functions are realized, thereby improving the detection performance of the thermoelectric detector and realizing high-precision measurement of the spectrum of external incident light.

[0064] As one embodiment of the present invention, regarding the case where the modulation structure 103 is located on a pixel of the detector array 104, such as Figure 7 As shown, the modulation structure 103 can be disposed on the pixels of the detector array 104 through the heat-conducting layer 701.

[0065] When the modulation structure 103 is disposed on the pixels of the detector array 104, in order to facilitate manufacturing and ensure the performance of the infrared thermoelectric spectroscopy imaging system, the modulation structure 103 can be disposed on the pixels of the detector array 104 through a heat-conducting layer 701. In this way, spectral modulation can be achieved in a plasmonic manner. Specifically, infrared radiation passes through the modulation structure 103 and then irradiates the heat-conducting layer 701. The heat-conducting layer 701 transfers heat to the pixels of the detector array 104, thereby causing a change in the electrical signal.

[0066] The heat-conducting layer 701 can be composed of heat-conducting materials such as metals, for example, gold, silver and aluminum, without being specifically limited here.

[0067] In one implementation, such as Figure 7 As shown, the modulation structure 103 can be oriented towards the infrared window 101. Of course, in another embodiment, such as... Figure 8 As shown, if the process allows, the modulation structure 103 can also be oriented toward the pixels of the detector array 104, which is reasonable.

[0068] As can be seen, in this embodiment, the modulation structure 103 can be disposed on the pixels of the detector array 104 through the heat-conducting layer 701, and can achieve spectral modulation of long-wave infrared radiation light through plasmon resonance, thereby improving the detection performance of the thermoelectric detector and realizing high-precision measurement of the spectrum of external incident light.

[0069] As one embodiment of the present invention, the above modulation structure may include multiple modulation units, each modulation unit may include multiple modulation sub-units, wherein each modulation sub-unit includes multiple identical modulation microstructures, and the modulation microstructures are uniformly distributed within the modulation sub-unit; the cross-sectional shapes of the modulation microstructures in different modulation sub-units of the same modulation unit are different.

[0070] In one embodiment, the modulation structure can be a single-layer structure, and the modulation structure can include multiple modulation units. For example, the modulation structure can include nine or sixteen uniformly distributed modulation units. Each modulation unit can include multiple modulation sub-units, for example, each modulation unit can include four uniformly distributed modulation sub-units, which is reasonable. The geometric arrangement of the modulation microstructure array in each modulation sub-unit can have C4 symmetry.

[0071] In one embodiment, the cross-sectional shape of the modulation microstructure in each modulation subunit may include a circle, an ellipse, a cross, a regular polygon, a star, or a rectangle, or any combination of the above shapes, without specific limitations.

[0072] Each modulation microstructure may include different structural parameters depending on its cross-sectional shape. For example, the structural parameters of a circular modulation microstructure may include aperture, the structural parameters of an elliptical modulation microstructure may include major axis and minor axis, the structural parameters of a cross-shaped or star-shaped modulation microstructure may include rotation angle and number of angles, and the structural parameters of a regular polygonal modulation microstructure may include side length.

[0073] For example, such as Figure 9 The modulation structure shown includes 16 modulation units, and the specific structure of each modulation unit can be as follows: Figure 10 As shown, the modulation unit may include four modulation subunits, each of which includes multiple identical modulation microstructures. The modulation microstructures are uniformly distributed within the modulation subunit, and the cross-sectional shapes of the modulation microstructures in different modulation subunits within the same modulation unit are different. Specifically, the modulation microstructures in the first modulation subunit 1001 have a circular cross-sectional shape, the modulation microstructures in the second modulation subunit 1002 have a cross-shaped cross-sectional shape, the modulation microstructures in the third modulation subunit 1003 have a triangular cross-sectional shape, and the modulation microstructures in the fourth modulation subunit 1004 have a regular hexagonal cross-sectional shape.

[0074] In one implementation, the cross-sectional shapes of the modulation microstructures in different modulation subunits within the same modulation unit can be the same, but the structural parameters corresponding to the modulation microstructures in different modulation subunits are different. For example, the cross-sectional shapes of the modulation microstructures corresponding to modulation subunits A and B in modulation unit 1 are both circular, but the aperture of the cross-sectional shape of the modulation microstructure in modulation subunit A is x, and the aperture of the cross-sectional shape of the modulation microstructure in modulation subunit B is y, and x is not equal to y. As another example, the cross-sectional shapes of the modulation microstructures corresponding to modulation subunits C and D in modulation unit 2 are both cross-shaped, but the rotation angle of the modulation microstructure in modulation subunit C is m, and the rotation angle of the modulation microstructure in modulation subunit D is n, and m is not equal to n. No specific limitations are made here. When infrared radiation is incident on the modulation structure, each modulation subunit corresponds to at least one pixel in a detector array. Each pixel is a hyperspectral spatial resolution unit, so the number of pixels in the detector array corresponding to each modulation subunit is at least 1. In practical use, the gray value of one pixel corresponding to the modulation subunit or the average value of multiple pixels can be selected as the gray value corresponding to that modulation subunit.

[0075] Because the cross-sectional shapes of the various modulation sub-units in the same modulation unit are different, or the structural parameters of the modulation microstructures with the same cross-section in different modulation sub-units of the same modulation unit are different, the transmittance of infrared light is also different. Therefore, different modulation effects on infrared light can be achieved. The changes in electrical signals caused by infrared light from different modulation sub-units are also different. Consequently, the gray values ​​of the pixels corresponding to the pixels of the detector array are also different. Therefore, after modulation by modulation sub-units with the same cross-sectional shape of the included modulation microstructures, a grayscale image corresponding to the modulation sub-unit with that cross-sectional shape can be generated. This grayscale image reflects the modulation effect of the modulation sub-unit with that cross-sectional shape on infrared light, and thus contains the spectral information corresponding to the modulation sub-unit with that cross-sectional shape.

[0076] For example, such as Figure 10 As shown, a single modulation unit includes four modulation subunits. A modulation subunit with a circular cross-section can generate a grayscale image 1, a modulation subunit with a cross-shaped cross-section can generate a grayscale image 2, a modulation subunit with a triangular cross-section can generate a grayscale image 3, and a modulation subunit with a regular hexagonal cross-section can generate a grayscale image 4. This results in four grayscale images containing spectral information. Of course, in actual display, these four grayscale images containing different spectral information can also be displayed in a single image, which is perfectly reasonable.

[0077] In one implementation, when the modulation structure is set on the pixels of the detector array, each modulation unit corresponds to one pixel, that is, one modulation unit is set on one pixel. In this way, one modulation unit corresponds to one pixel, and the modulation units do not affect each other, which can minimize the spectral modulation difference caused by the incident angle.

[0078] As can be seen, in this embodiment, the modulation structure includes multiple modulation units, each modulation unit includes multiple modulation sub-units, and each modulation sub-unit includes multiple identical modulation microstructures. The modulation microstructures are uniformly distributed within the modulation sub-unit, and the cross-sectional shapes of the modulation microstructures in different modulation sub-units within the same modulation unit are different. This modulation structure enables better modulation of infrared light, thereby improving the performance of the infrared thermoelectric spectroscopy imaging system.

[0079] As one embodiment of the present invention, the above-mentioned modulation microstructure can be an infrared high-transmittance material modulation column, an infrared high-transmittance material modulation hole, or a metal modulation hole.

[0080] In one embodiment, the above-mentioned modulation microstructure can be an infrared high-transmittance material modulation column, wherein the infrared high-transmittance material modulation column can be a modulation column made of infrared high-transmittance materials such as silicon (Si), silicon dioxide (SiO2), germanium (Ge), zinc sulfide (ZnS) and ytterbium fluoride (Cas).

[0081] When the modulation microstructure is a modulation column made of infrared high-transmittance material, if the modulation column is placed on the infrared window, its material can be the same as the infrared window material. As one implementation method, the modulation column can be placed on the infrared window by vapor deposition, electroplating, electrochemical coating, etc., all of which are reasonable and are not specifically limited here.

[0082] When the modulation microstructure is a modulation aperture made of infrared high-transmittance material, if the modulation aperture is located on the infrared window, its material can be the same as that of the infrared window. As one implementation method, the modulation aperture can be formed on one side of the infrared window by etching or other methods, which is reasonable and not specifically limited here.

[0083] The cross-sectional shape of the modulation aperture of the infrared high-transmittance material can also include circular, elliptical, cross-shaped, regular polygonal, star-shaped, or rectangular shapes, or any combination of the above shapes, without specific limitations.

[0084] When the modulation microstructure is a metal modulation aperture, and the modulation structure is located on a pixel of the detector array, the metal layer forming the metal aperture is disposed on the thermally conductive layer through a dielectric layer. The modulation metal aperture can be a hole formed in a metal layer made of metal materials such as gold, silver, or aluminum; no specific limitation is made here.

[0085] The cross-sectional shape of the metal modulation aperture can include circular, elliptical, cross-shaped, regular polygonal, star-shaped, or rectangular shapes, or any combination of the above shapes; no specific limitation is made here. For example, Figure 11 The modulation subunit shown can include metal modulation holes with four cross-sectional shapes: circular, cross-shaped, triangular, and regular hexagonal.

[0086] As can be seen, in this embodiment, the modulation microstructure is an infrared high-transmittance material modulation column, an infrared high-transmittance material modulation hole, or a metal modulation hole. Regardless of the type of modulation microstructure used, it can effectively modulate infrared light.

[0087] As one embodiment of the present invention, the distance between the metasurface of the modulation microstructure and the pixels of the detector array can be 10μm-2000μm.

[0088] like Figure 12As shown, taking the case where the modulation structure 103 is located on the side of the infrared window 101 facing the detector array 104, and the filter film 102 is attached to the other side of the infrared window 101 as an example, the filter film 102, the infrared window 101, and the modulation structure 103 constitute a multifunctional spectral filter structure. External infrared radiation will converge on the side of the infrared window 101 facing the imaging lens 110, and the converged light will cover a circle with diameter L. The size of L is positively correlated with the distance between the metasurface of the modulation structure 103 (i.e., the surface where the modulation microstructure is located) and the FPA (Focal Plane Array), i.e., the detector array 104. Specifically, the smaller the distance between the metasurface of the modulation structure 103 and the FPA, the smaller L is.

[0089] Infrared light emitted from a specific spatial location, after entering the infrared window, only covers a single modulation sub-unit, thus avoiding crosstalk between different modulation sub-units on the modulated light. Therefore, the distance between the metasurface of the modulation structure 103 and the FPA can be set as small as possible so that the infrared light, after entering the infrared window, only covers a single modulation sub-unit.

[0090] Therefore, in order to reduce the crosstalk between the modulation curves corresponding to different sub-modulation units, the distance between the metasurface of the modulation structure 103 and the FPA can be reduced, that is, the modulation structure 103 can be set on the side of the infrared window 101 facing the detector array 104.

[0091] Based on the above principle, the distance between the metasurface of the modulation microstructure and the pixels of the detector array can be controlled within the range of 10μm-2000μm, thereby further reducing the influence of crosstalk between the modulation curves corresponding to different modulation sub-units.

[0092] As can be seen, in this embodiment, the distance between the metasurface of the modulation microstructure and the pixels of the detector array is 10μm-2000μm, which can reduce the crosstalk between the modulation curves corresponding to different sub-modulation units, thereby further improving the performance of the infrared thermoelectric spectroscopy imaging system.

[0093] As one embodiment of the present invention, considering the complexity of the process and the size requirements of the infrared thermoelectric spectroscopy imaging system, the height of the above-mentioned modulation microstructure can be 2μm-10μm, the period range of the modulation microstructure can be 2μm-12μm, the number of periods of each modulation microstructure can be 4-100, and the duty cycle of the modulation microstructure in each modulation subunit can be 10%-90%.

[0094] For example, such as Figure 13The infrared high-transmittance material modulation column 1301 shown has a circular cross-sectional shape. D is the aperture of the infrared high-transmittance material modulation column 1301, P is the period range corresponding to the infrared high-transmittance material modulation column 1301, and h is the height of the infrared high-transmittance material modulation column 1301. The range of h can be 2μm-10μm, and the range of P can be 2μm-12μm.

[0095] The number of periods for each modulation microstructure can be 4-100, meaning that modulation microstructures with various cross-sectional shapes can have 4-100 periods. In other words, each modulation unit can include 4-100 modulation subunits. For example... Figure 9 The modulation unit shown has 16 cycles.

[0096] The duty cycle of the modulation microstructures within each modulation subunit is 10%-90%. The duty cycle can be calculated by dividing the cross-sectional area of ​​all modulation microstructures within the modulation subunit by the cross-sectional area of ​​the modulation subunit itself.

[0097] With a duty cycle of 10%-90% and a period range of 2μm-12μm for the modulation microstructure, the period size of each modulation microstructure can be determined to be 6μm-1200μm, which is the size of the range occupied by each modulation microstructure in the corresponding modulation subunit.

[0098] As can be seen, in this embodiment, the height of the modulation microstructure can be 2μm-10μm, the period of the modulation microstructure can be 2μm-12μm, the number of periods for each modulation microstructure can be 4-100, and the duty cycle of the modulation microstructure within each modulation subunit can be 10%-90%. This allows for better optical wave modulation, thereby improving the performance of the infrared thermoelectric spectroscopy imaging system, while also facilitating fabrication and reducing costs.

[0099] As one embodiment of the present invention, the infrared window and the detector array can be integrated into a single package, and the space between the infrared window and the detector array can be a vacuum environment.

[0100] Integrated packaging offers the following advantages: 1. High packaging efficiency: It utilizes a batch production process on a single wafer, significantly improving packaging efficiency by packaging multiple detectors at once. 2. Full utilization of existing wafer manufacturing equipment: No separate detector packaging production line is required. 3. Small package size and short leads: This results in better electrical performance.

[0101] Therefore, by integrating the infrared window and the detector array into a single package, the distance between the infrared window and the detector array can be reduced, the size of the thermoelectric detector can be decreased, and the effect of approximately one-to-one between the modulation subunit and each pixel in the detector array can be achieved as much as possible. This reduces crosstalk between modulation curves of different modulation subunits, thereby achieving higher resolution and reducing packaging costs.

[0102] Since the principle of infrared thermoelectric spectroscopy imaging systems is to convert light signals into heat, and then heat into electrical signals, a vacuum environment can be maintained between the infrared window and the detector array to ensure good thermal insulation and improve the performance of the system. For example, a getter can be used to ensure a vacuum environment between the infrared window and the detector array.

[0103] Corresponding to the aforementioned infrared thermoelectric spectroscopy imaging system, this invention provides an infrared imaging method, which is described below. The infrared imaging method provided by this invention can be applied to the imaging detector in an infrared thermoelectric spectroscopy imaging system, or to other devices that are communicatively connected to the infrared thermoelectric spectroscopy imaging system. No specific limitations are made here; these are hereinafter referred to as electronic devices.

[0104] like Figure 14 As shown, an infrared imaging method may include:

[0105] S1401, Obtain the grayscale image corresponding to the target object;

[0106] The grayscale image can be obtained by the infrared thermoelectric spectroscopy imaging system described in any of the above embodiments;

[0107] S1402, Based on the grayscale image, a hyperspectral image corresponding to the target object is generated using a spectral inversion algorithm.

[0108] As can be seen, in the solution provided by the embodiments of this disclosure, the electronic device can acquire the grayscale image corresponding to the target object collected by the infrared thermoelectric spectroscopy imaging system, and then generate the hyperspectral image corresponding to the target object based on the grayscale image through a spectral inversion algorithm. Since the infrared thermoelectric spectroscopy imaging system can obtain the grayscale image corresponding to the target object with high accuracy, the hyperspectral image corresponding to the target object can be generated accurately based on the grayscale image through a spectral inversion algorithm, thereby improving the accuracy of subsequent image analysis and other processing results based on the hyperspectral image.

[0109] In one embodiment, infrared radiation in the long-wave infrared band passes through the imaging lens of the infrared thermoelectric spectral imaging system and is then filtered through a filter film to achieve broadband filtering. The broadband filtered infrared radiation is then injected into different modulation microstructures. The spectral modulation effect of modulation microstructures with different cross-sectional shapes is different. The readout circuit of the corresponding pixel of the detector array for each type of modulation microstructure has a different reading. Therefore, grayscale information corresponding to multiple spectral modulation types can be obtained for each modulation sub-unit.

[0110] By extracting the grayscale values ​​of pixels in the detector array corresponding to the modulation microstructures with the same cross-sectional shape in all modulation subunits, multiple grayscale images can be obtained. Each grayscale image has a different spectral modulation effect due to the influence of different modulation effects. By inputting the different grayscale images into the spectral inversion algorithm, a hyperspectral image of the target object can be obtained. The spectral inversion algorithm can be a compressed sensing algorithm or a deep learning algorithm, etc.

[0111] As one embodiment of the present invention, after the step of generating a hyperspectral image corresponding to the target object based on the grayscale image using a spectral inversion algorithm, the method may include:

[0112] Based on the hyperspectral image, the properties of the target object are determined.

[0113] Because hyperspectral images include both image information and spectral information of the target object, and image information can reflect the external physical characteristics of the target object such as size, shape, and defects; different components of the target object absorb light to different degrees, and spectral information at a specific wavelength will clearly reflect a certain defect, spectral information can fully reflect the internal physical structure and chemical composition differences of the target object. Therefore, based on the hyperspectral image of the target object, the properties of the target object can be accurately determined, including physical and / or chemical properties.

[0114] As can be seen, in this embodiment, the electronic device can determine the properties of the target object based on the hyperspectral image. Since the infrared thermoelectric spectroscopy imaging system can obtain a highly accurate hyperspectral image of the target object, the properties of the target object can be accurately determined based on the hyperspectral image.

[0115] In an optional embodiment of the present invention, the infrared thermoelectric spectral imaging system can detect whether there is a leak of dangerous chemical gases in the air, such as methane, sulfide gas, ammonia, etc., based on the detected changes in the radiation spectrum in the air. It can also be used for scenarios such as temperature measurement and fire detection.

[0116] Alternatively, an infrared thermoelectric spectroscopy imaging system can detect water quality based on changes in the spectrum of radiation emitted from water, thereby enabling water quality monitoring.

[0117] In another embodiment of the present invention, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of the infrared imaging method described in any of the above embodiments.

[0118] In another embodiment of the present invention, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the infrared imaging methods described in the above embodiments.

[0119] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0120] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0121] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. An infrared thermoelectric spectroscopy imaging system, characterized in that, The system includes an imaging lens and a thermoelectric detector, wherein the thermoelectric detector includes an infrared window, a filter film, a modulation structure, and a detector array, wherein: The imaging lens, the infrared window, and the detector array are arranged sequentially along the optical axis of the imaging lens. The modulation structure is located on the side of the infrared window facing the detector array, and the filter film is attached to the other side of the infrared window to form a multifunctional spectral filter comprising a filter film, an infrared window, and a modulation structure; the space between the infrared window and the detector array is a vacuum environment. The modulation structure includes multiple modulation units, and each modulation unit includes multiple modulation subunits; Each of the modulation sub-units includes multiple identical modulation microstructures; the distance between the metasurface of the modulation microstructure and the pixels of the detector array is 10μm-2000μm.

2. The system according to claim 1, characterized in that, The modulation microstructures are uniformly distributed within the modulation subunit; the cross-sectional shapes of the modulation microstructures in different modulation subunits within the same modulation unit are different.

3. The system according to claim 2, characterized in that, The modulation microstructure is an infrared high-transmittance material modulation column, an infrared high-transmittance material modulation hole, or a metal modulation hole.

4. The system according to claim 2, characterized in that, The height of the modulation microstructure is 2μm-10μm, the period of the modulation microstructure is 2μm-12μm, the number of periods of each modulation microstructure is 4-100, and the duty cycle of the modulation microstructure in each modulation subunit is 10%-90%.

5. An infrared imaging method, characterized in that, The method includes: Acquire a grayscale image corresponding to the target object, wherein the grayscale image is obtained by the infrared thermoelectric spectroscopy imaging system according to any one of claims 1-4; Based on the grayscale image, a hyperspectral image corresponding to the target object is generated using a spectral inversion algorithm.

6. The method according to claim 5, characterized in that, After the step of generating a hyperspectral image corresponding to the target object based on the grayscale image using a spectral inversion algorithm, the method includes: Based on the hyperspectral image, the properties of the target object are determined, wherein the properties include physical properties and / or chemical properties.

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