On-chip spectroscopic mid-infrared detection device, equipment and imaging method

Abstract

The present invention relates to an on-chip spectroscopic mid-infrared detection device, equipment and imaging method, comprising: a two-color coupled spectroscopic grating, a first mode spot conversion structure, a second mode spot conversion structure, a first transmission waveguide, a second transmission waveguide, a first packaging module, a second packaging module, a first photoelectric detection, a second photoelectric detection, a first refrigeration structure, and a second refrigeration structure; wherein, after the mid-infrared light is injected from the two-color coupled spectroscopic grating, two-color coupling is performed, and then the first and second mode spot conversion structures on both sides of the two-color coupled spectroscopic grating are respectively passed through, and then the first and second transmission waveguides are respectively transmitted to the first and second photoelectric detections, and the detection of the first and second wavelengths is output; the first and second packaging modules encapsulate the first and second photoelectric detections respectively, and the first and second refrigeration structures cover the first and second packaging modules respectively. The present invention can reduce interference, realize two-color imaging and high-efficiency, large-bandwidth multi-wavelength detection, and reduce the cost of the detector.

Description

Technical Field

[0001] The invention relates to the technical field of optoelectronic devices, and in particular to an on-chip spectroscopic mid-infrared detection device. Background Art

[0002] On-chip spectrometry and detection are key components for realizing photoelectric conversion in optoelectronic fusion chips. At present, on-chip spectrometry and detection solutions for visible light to near-infrared bands are relatively mature. On the contrary, for the mid-infrared band (2-14μm), there is still no mature technical solution available for on-chip spectrometry and detection. The mid-infrared band is a very important optical band in both science and technology. It covers the chemical molecular fingerprint region and two atmospheric windows (3-5μm and 8-12μm), and contains a large amount of characteristic information of molecular vibration and thermal radiation. The development of light detection technology in this band is of great significance to fields such as scientific research and industrial applications, such as chemical analysis, gas detection, environmental monitoring, lidar, free-space optical communication and remote sensing technology.

[0003] Early mid-infrared detectors only detect one wavelength. Single wavelength detection tends to provide incomplete information, which can easily cause misjudgment in the later information processing system. In mid-infrared imaging, multi-band fusion imaging can greatly reduce information misjudgment. With the development of semiconductor materials and process technology, people will define the ability to detect multiple bands at the same time as a typical feature of the third-generation mid-infrared detector, and multi-band detection is a necessary condition for the later fusion imaging. At present, the common method to achieve multi-band detection is to vertically stack multiple detection material layers for different bands. Taking a two-color detector as an example, after the light is vertically incident on the detector, the shorter wavelength light is absorbed by the upper material, and the longer wavelength light is absorbed by the lower material, thereby generating a photocurrent detection signal. Typical representatives include HgCdTe dual-band detectors, quantum well detectors, and type II InAs / GaSb superlattice dual-band detectors. The light incident direction of the above detectors coincides with the carrier transport direction, so it is easy to introduce large noise and limit the response speed of the detector.

[0004] However, the preparation of existing infrared multi-band detectors in vertical stacked structures is difficult and costly. In addition, the light incident direction and carrier transport direction are both perpendicular, which easily introduces noise and limits the response speed. In addition, the cooling structure is closely integrated with the light incident part and the photoelectric detection part, which will introduce additional background noise. Summary of the invention

[0005] The present invention provides an on-chip spectroscopic mid-infrared detection device, equipment and imaging method to reduce the noise introduced by the vertically incident mid-infrared light and the noise introduced by the device itself in the mid-infrared band detection, improve the response speed and reduce the cost.

[0006] In a first aspect, an embodiment of the present invention provides an on-chip spectroscopic mid-infrared detection device, the device comprising: a two-color coupled spectroscopic grating, a first mode spot conversion structure, a second mode spot conversion structure, a first transmission waveguide, a second transmission waveguide, a first packaging module, a second packaging module, a first photoelectric detection, a second photoelectric detection, a first refrigeration structure, and a second refrigeration structure; wherein,

[0007] The mid-infrared light is incident from the two-color coupling splitting grating, undergoes two-color coupling splitting, and then passes through the first mode spot conversion structure and the second mode spot conversion structure on both sides of the two-color coupling splitting grating respectively, and then is transmitted to the first photoelectric detection and the second photoelectric detection through the first transmission waveguide and the second transmission waveguide respectively, and outputs the detection of the first wavelength and the detection of the second wavelength;

[0008] The first packaging module and the second packaging module respectively package the first photoelectric detection and the second photoelectric detection, and the first cooling structure and the second cooling structure respectively cover the first packaging module and the second packaging module.

[0009] The present invention adopts a two-color coupled spectroscopic grating for dual-wavelength spectroscopic detection, and can construct photoelectric detection for two mid-infrared wavelengths respectively, thereby realizing high-speed, large-bandwidth multi-wavelength detection; a packaging module is set on the detection part of the spectrometer, which can effectively separate the photoelectric detection part from the light incident part, that is, the spectroscopic part, so as to realize independent operation of the detection part and the coupled spectroscopic part, so as to reduce the influence of noise caused by environmental factors and improve the detection signal-to-noise ratio; in addition, the refrigeration structure set at the packaging module can immediately provide refrigeration, quickly reduce the carriers generated by thermal excitation, and thus quickly reduce thermal noise interference.

[0010] The on-chip spectroscopic mid-infrared detection device further comprises:

[0011] A first shielding structure and a second shielding structure are respectively arranged on both sides of the two-color coupling spectroscopic grating and between the first cooling structure and the second cooling structure; wherein the first cooling structure is connected to the first shielding structure, the second cooling structure is connected to the second shielding structure, and the first shielding structure and the second shielding structure are also respectively connected to one side of the two-color coupling spectroscopic grating.

[0012] The refrigeration structure of the present invention covers the packaging module, and can realize rapid cooling of the photoelectric detection structure in the packaging structure; in addition, the refrigeration structure is connected to the shielding structure, and the shielding structure is connected to the two-color coupled spectroscopic grating, which can isolate the interference of stray light from the external environment to the detection structure to the greatest extent, so that the photoelectric detection structure only receives light of the corresponding wavelength transmitted by the spectroscopic array, thereby reducing noise interference from the external environment.

[0013] Further, the first refrigeration structure and the second refrigeration structure are respectively provided at the first packaging module and the second packaging module, including:

[0014] The first refrigeration structure and the second refrigeration structure cover the first packaging module and the second packaging module respectively.

[0015] The first shielding structure and the second shielding structure are respectively provided, comprising:

[0016] The first shielding structure covers the first transmission waveguide and the first mode spot conversion structure, and the second shielding structure covers the second mode spot conversion structure and the second transmission waveguide.

[0017] The present invention adopts a shielding structure to completely cover the transmission waveguide and the mode spot conversion structure, which can isolate the interference of the on-chip spectrometer itself and the environment on the detection structure, and further reduce noise interference; in addition, the refrigeration device and the shielding structure are simple to implement, and the refrigeration device is arranged on the on-chip spectrometer, which can effectively reduce the influence of environmental thermal noise on the detector.

[0018] Furthermore, the mid-infrared light includes: an input wavelength including a 2-14 μm band of mid-infrared light, and the mid-infrared light can be vertically or obliquely incident on the two-color coupling spectroscopic grating.

[0019] The present invention can not only vertically inject mid-infrared light onto the two-color coupled spectroscopic grating, but also obliquely inject mid-infrared light onto the two-color coupled spectroscopic grating, thereby further reducing the angle restriction on the incident light.

[0020] Furthermore, the structure of the two-color coupled spectroscopic grating includes: a uniform periodic grating structure that meets the Bragg condition, and a non-uniform periodic grating structure optimized based on various inverse algorithms; wherein the non-uniform periodic grating structure includes: apodization gratings, two-dimensional gratings and other gratings with spectroscopic function.

[0021] The present invention adopts a uniform periodic grating structure with a constant period and duty cycle, and also adopts an optimized non-uniform periodic grating structure. Through inverse algorithm optimization, the grating diffraction light field of the non-uniform periodic grating structure matches the light field of the single-mode optical fiber, which can improve the efficiency of the two-color coupled spectroscopic grating.

[0022] Furthermore, the first refrigeration structure and the second refrigeration structure adopt refrigeration methods including: liquid nitrogen refrigeration and semiconductor refrigeration.

[0023] In a second aspect, the present invention provides an on-chip spectroscopic mid-infrared detection device, comprising a plurality of groups of on-chip spectroscopic mid-infrared detection devices as described in the first aspect.

[0024] Furthermore, the on-chip spectroscopic mid-infrared detection device further includes: a plurality of groups of on-chip spectroscopic detection devices are arranged vertically on a substrate, and the wavelengths detected by the on-chip spectroscopic detection devices between the groups may all be the same or different.

[0025] The present invention adopts a plurality of groups of identical two-color spectroscopic detection devices arranged vertically, thereby expanding the spatial size of mid-infrared detection; this type of two-color spectroscopic detection arrangement extends single-point two-color spectroscopic detection to multi-point detection / pixelated detection, thereby realizing the two-color spectroscopic detection imaging function; in addition, a plurality of groups of different two-color spectroscopic detection devices are arranged vertically, and an array arrangement facing a plurality of groups of different two-color spectroscopic detection devices is adopted, thereby expanding the working wavelength.

[0026] In the third aspect, the present invention also provides an on-chip spectroscopic mid-infrared imaging method, which is applied to the on-chip spectroscopic mid-infrared detection device as described in the second aspect, including: acquiring the intensity information of two or more wavelengths of imaging through mid-infrared two-color spectroscopic detection, and then fusing the images through a fusion algorithm to reconstruct imaging.

[0027] Furthermore, the method of obtaining the intensity information of two or more wavelengths of imaging by mid-infrared two-color spectroscopic detection includes:

[0028] According to different wavelengths, the structural parameters of the two-color coupled spectroscopic grating are adjusted, and the structural parameters include: grating period, etching depth, and duty cycle.

[0029] The present invention adjusts the mid-infrared two-color spectroscopic detection array structure to obtain two-color intensity information of the imaging wavelength, and then realizes fusion imaging through algorithm reconstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a mid-infrared two-color spectroscopic detection device provided by an embodiment of the present invention;

[0031] Figure 2 is a structural schematic diagram of a mid-infrared two-color spectroscopic detection device with a cooling structure and a shielding structure provided in an embodiment of the present invention;

[0032] Figure 3 It is a structural schematic diagram of a mid-infrared two-color spectroscopic detection device provided by an embodiment of the present invention;

[0033] Figure 4 It is a structural schematic diagram of a mid-infrared multi-color spectroscopic detection device provided by an embodiment of the present invention;

[0034] Figure 5 It is a schematic diagram of linear scanning imaging based on a mid-infrared spectroscopic detection device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1 , is a schematic diagram of the structure of a mid-infrared two-color spectroscopic detection device provided by an embodiment of the present invention, Figure 1 (a) is a schematic diagram of the structure of a mid-infrared two-color spectroscopic detection device, including: a two-color coupled spectroscopic grating 5, a first mode spot conversion structure 4, a second mode spot conversion structure 6, a first transmission waveguide 2, a second transmission waveguide 7, a first packaging module 3, a second packaging module 9, a first photoelectric detector 1, and a second photoelectric detector 8.

[0037] Among them, the mid-infrared light is incident from the two-color coupling splitter grating 5 and undergoes two-color coupling, and then passes through the first mode spot conversion structure 4 and the second mode spot conversion structure 6 on both sides of the two-color coupling splitter grating respectively, and then is transmitted to the first photoelectric detection 1 and the second photoelectric detection 8 through the first transmission waveguide 2 and the second transmission waveguide 7 respectively, and outputs the detection of the first wavelength and the detection of the second wavelength.

[0038] Figure 1 (b) is a structural side view of a mid-infrared two-color spectroscopic detection device. In the figure, structures 1 and 8 correspond to the first photoelectric detection and the second photoelectric detection, respectively, and structures 3 and 9 correspond to the first packaging module and the second packaging module, respectively.

[0039] It is worth noting that the first photodetector 1 and the second photodetector 8 respectively realize the detection of the transmission wavelength λ1 in the 8-12μm band and the transmission wavelength λ2 in the 3-5μm band; the spectrometer and optical transmission components are prepared based on the germanium (Ge) layer, and underneath the germanium (Ge) layer is a silicon-on-insulator (SOI) substrate, or other substrate materials with a lower refractive index than germanium (Ge).

[0040] The optical signal is incident vertically or at a certain angle (0-90°) onto the surface of the two-color coupling spectroscopic grating 5 through optical fiber guidance or free space light. The wavelength λ1 is converted from the transmission mode to the single mode through the mode conversion structure 4 and then transmitted in the single mode along the first transmission waveguide 2. The first photoelectric detector 1 detects the wavelength λ1, and the first packaging module 3 packages the first photoelectric detector 1. The wavelength λ2 is converted from the transmission mode to the single mode through the mode conversion structure 6 and then transmitted in the single mode along the second transmission waveguide 7. The second photoelectric detector 8 detects the wavelength λ2, and the second packaging module 9 packages the second photoelectric detector 8.

[0041] It is worth noting that the encapsulation module and shielding structure are not limited to cylindrical, cube and other structures for encapsulation / shielding, and materials with encapsulation / shielding effects are selected.

[0042] Preferably, the structure of the two-color coupled spectroscopic grating 5 includes: a uniform periodic grating structure satisfying the Bragg condition, and a non-uniform periodic grating structure obtained by optimizing based on various inverse algorithms.

[0043] It is worth noting that the two-color coupled spectroscopic grating is not only applicable to uniform periodic gratings, but also to other forms of gratings such as apodized gratings, two-dimensional gratings and other gratings with spectroscopic functions.

[0044] Preferably, the grating period of the uniform periodic grating structure is 2.55 μm, the duty cycle (DC) is 0.55, the number of periods is 7, and the etching depth is 1.05 μm; the non-uniform periodic grating is obtained by direct binary search optimization, and 132 cells with a minimum characteristic size of 0.15 μm are set. After cell flipping tests one by one, multiple rounds of optimization are performed to obtain an irregular cell flipping state, i.e., a non-uniform periodic grating, and the etching depth is set to 1 μm, in order to achieve high dual-wavelength coupling efficiency. The material of the first photoelectric detection 1 of the wavelength λ1 of 8-12 μm is a two-dimensional material stacked multi-heterojunction structure, and the corresponding response wavelength is obtained by adjusting the band gap; the material of the second photoelectric detection 8 of the wavelength λ2 of 3-5 μm is lead selenide (PbSe).

[0045] See also Figure 2 , is a structural schematic diagram of a mid-infrared two-color spectroscopic detection device with added refrigeration structure and shielding structure provided in an embodiment of the present invention; the figure includes: a refrigeration structure 10 corresponding to the wavelength λ1, a refrigeration structure 11 corresponding to the wavelength λ2, a first shielding structure 12, and a second shielding structure 13.

[0046] It is worth noting that the first refrigeration structure 10 and the second refrigeration structure 11 cover the first packaging module 1 and the second packaging module 9 respectively; and the first refrigeration structure 10 is closely connected to the first shielding structure 12, the second refrigeration structure 11 is closely connected to the second shielding structure 13, and the first shielding structure 12 and the second shielding structure 13 are also closely connected to one side of the two-color coupling spectroscopic grating 5 respectively; in addition, the first shielding structure 12 covers the first transmission waveguide 2 and the first mode spot conversion structure 4, and the second shielding structure 13 covers the second mode spot conversion structure 6 and the second transmission waveguide 7.

[0047] Preferably, the refrigeration methods of the first refrigeration structure and the second refrigeration structure include: liquid nitrogen refrigeration and semiconductor refrigeration; wherein the refrigeration structure of liquid nitrogen refrigeration is a liquid nitrogen Dewar, and the container structure is used to directly store liquid nitrogen, and semiconductor refrigeration is a refrigeration method based on the Peltier effect (thermoelectric effect), which can achieve precise temperature control refrigeration.

[0048] The present invention also provides an on-chip spectroscopic mid-infrared detection device, comprising a plurality of groups of on-chip spectroscopic mid-infrared detection devices as described in the first aspect.

[0049] Furthermore, the on-chip spectroscopic mid-infrared detection device further includes: a plurality of groups of on-chip spectroscopic detection devices are arranged vertically on a substrate, and the wavelengths detected by the on-chip spectroscopic detection devices between the groups may all be the same or different.

[0050] The present invention arranges a plurality of groups of on-chip spectroscopic detection devices in an array on the same substrate, which can overcome the limitation that the spectroscopic detection array is subject to the dual wavelength of the coupled grating and expand to a plurality of application wavelengths.

[0051] The present invention provides a Figure 1 Schematic diagram of several sets of two-color spectroscopic detection devices, see Figure 3 , is a structural schematic diagram of a mid-infrared two-color spectroscopic detection device provided by an embodiment of the present invention. In the figure, a mid-infrared two-color spectroscopic detection device is formed by a plurality of groups of mid-infrared two-color spectroscopic detection devices arranged in an array. The wavelengths detected by the two-color spectroscopic detection devices between groups are all the same, and the wavelengths detected by the mid-infrared two-color spectroscopic detection devices within a group are different.

[0052] The present invention adopts multiple groups of on-chip spectroscopic detection devices arranged vertically, which expands the spatial size of mid-infrared detection; in addition, by increasing the number of two-color spectroscopic detection devices, single-point two-color spectroscopic detection is extended to multi-point detection / pixel detection, forming a one-dimensional array, which can realize one-dimensional light detection for two fixed mid-infrared wavelengths and thus realize multi-pixel array imaging, as well as realize two-color spectroscopic detection imaging function.

[0053] The present invention also provides a Figure 1 Schematic diagram of several sets of multi-color spectroscopic detection structures, see Figure 4 , is a structural schematic diagram of a mid-infrared multi-color spectroscopic detection device provided by an embodiment of the present invention. In the figure, a mid-infrared multi-color spectroscopic detection device is formed by a plurality of groups of mid-infrared two-color spectroscopic detection devices arranged in an array. The wavelengths detected by the two-color spectroscopic detection devices between groups are all different, or the detected wavelengths may be partially the same, and the wavelengths detected by the mid-infrared two-color spectroscopic detection devices within the group are different.

[0054] The present invention uses optical signals to be guided by optical fibers or in free space to be incident on the surface of the two-color coupled spectroscopic grating 5, and forms a two-color spectroscopic detection array in a linear array arrangement, which expands the working wavelength for the array arrangement of multiple groups of different two-color spectroscopic detection devices.

[0055] Exemplarily, the input light is a wide-spectrum light including wavelengths λ1, λ2, λ3, λ4, λ5, λ6, λ7, and λ8; wherein the two-color coupled spectroscopic grating 5 of each group of mid-infrared multicolor spectroscopic detection structures is different, and the grating structure parameters are designed and optimized for two different target wavelengths, including: grating period and etching depth. The wavelengths processed by multiple different coupled spectroscopic gratings are λ1, λ3, λ5, and λ7 are wavelengths within the mid-infrared 8-14μm band, and λ2, λ4, λ6, and λ8 are wavelengths within the mid-infrared 3-5μm band.

[0056] It is worth noting that the array form of several groups of mid-infrared two-color spectroscopic detection devices can be a linear array, a two-dimensional array or other array structures, which is not limited here; in addition, if the cooling structure and the shielding structure are arranged on each group of mid-infrared two-color spectroscopic detection devices of the mid-infrared two-color spectroscopic detection array device to form a device with cooling and shielding / packaging functions, it also falls within the protection scope of the present invention.

[0057] The present invention adopts a mid-infrared two-color spectroscopic detection array, and realizes spectroscopic transmission from space to on-chip waveguide based on a two-color coupled spectroscopic grating; further, by constructing a mid-infrared two-color spectroscopic detection array, it can realize the expansion from single-point detection to multi-point detection / pixelated detection; constructing a mid-infrared multi-color spectroscopic detection array for different two-color wavelengths further expands the application working wavelength.

[0058] An embodiment of the present invention provides an on-chip spectroscopic mid-infrared imaging method, which is applied to an on-chip spectroscopic mid-infrared detection device, including: acquiring intensity information of two or more wavelengths of imaging through mid-infrared two-color spectroscopic detection, and then fusing the images through a fusion algorithm to reconstruct imaging.

[0059] Furthermore, the method of obtaining the intensity information of two or more wavelengths of imaging by mid-infrared two-color spectroscopic detection includes:

[0060] According to different wavelengths, the structural parameters of the two-color coupled spectroscopic grating are adjusted, and the structural parameters include: grating period, etching depth, and duty cycle.

[0061] The present invention adjusts the mid-infrared two-color spectroscopic detection array structure to obtain two-color intensity information of the imaging wavelength, and then realizes fusion imaging through algorithm reconstruction.

[0062] See also Figure 5 , is a schematic diagram of linear scanning imaging based on a mid-infrared spectroscopic detection device provided by an embodiment of the present invention. In the figure, mid-infrared light passes through a mid-infrared two-color spectroscopic detection device, and intensity information of two or more wavelengths can be obtained from both sides of the mid-infrared two-color spectroscopic detection device, and then the intensity information of the two or more wavelengths is scanned and imaged.

[0063] It is worth noting that, in addition to being used in the linear scanning method, the imaging method can also be applied to other scanning imaging methods, which are not limited here.

[0064] The present invention adopts an on-chip spectroscopic grating, which can naturally filter out visible light. Therefore, the detection noise and interference caused by the incident visible light can be eliminated without the need for an additional visible light filter; the mid-infrared light can be incident on the two-color coupled spectroscopic grating at an angle, which can overcome the problems of difficult vertical integration of different light-absorbing materials and high dark current noise in traditional multi-color mid-infrared detectors, and can configure the best light-absorbing material for the detection of each mid-infrared wavelength to achieve efficient detection of each wavelength; the electrical detection structure is spatially separated from the optical coupling / incident part, and combined with the packaging / shielding treatment of the photoelectric detection, it can more effectively reduce the influence of environmental background noise on the mid-infrared light detection; the on-chip single mid-infrared two-color spectroscopic detection device can be used for detecting the mid-infrared light. The overscanning method can achieve two-color imaging of the target. The on-chip mid-infrared two-color spectroscopic detection equipment has further expanded the single-pixel detection that is currently commonly used in on-chip mid-infrared, and arranged several groups of mid-infrared two-color spectroscopic detection devices in an array, thereby expanding its arrayed / pixelated detection capabilities. In addition, the mid-infrared two-color spectroscopic detection equipment introduces coupled spectroscopic gratings corresponding to different dual wavelengths and arranges the spectroscopic detection structure in an array. This can overcome the limitation of the spectroscopic detection array being restricted by the dual wavelengths of the coupled grating, expand the application wavelength, and realize multi-wavelength spectroscopic detection of a single detection array. In addition, the new structure can greatly reduce the requirements for detection material growth and device preparation, thereby greatly reducing the cost of the detector.

[0065] The description of the positional relationship in the accompanying drawings is only for illustrative purposes and should not be construed as a limitation on this patent; obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. An on-chip spectroscopic mid-infrared detection device, characterized in that: The device comprises: a two-color coupled spectroscopic grating, a first mode spot conversion structure, a second mode spot conversion structure, a first transmission waveguide, a second transmission waveguide, a first packaging module, a second packaging module, a first photoelectric detection, a second photoelectric detection, a first refrigeration structure, and a second refrigeration structure; wherein, The mid-infrared light is incident from the two-color coupling splitting grating, undergoes two-color coupling splitting, and then passes through the first mode spot conversion structure and the second mode spot conversion structure on both sides of the two-color coupling splitting grating respectively, and then is transmitted to the first photoelectric detection and the second photoelectric detection through the first transmission waveguide and the second transmission waveguide respectively, and outputs the detection of the first wavelength and the detection of the second wavelength; The first packaging module and the second packaging module respectively package the first photoelectric detection and the second photoelectric detection, and the first cooling structure and the second cooling structure respectively cover the first packaging module and the second packaging module.

2. The on-chip spectroscopic mid-infrared detection device according to claim 1, characterized in that: Also includes: A first shielding structure and a second shielding structure are respectively arranged on both sides of the two-color coupling spectroscopic grating and between the first cooling structure and the second cooling structure; wherein the first cooling structure is connected to the first shielding structure, the second cooling structure is connected to the second shielding structure, and the first shielding structure and the second shielding structure are also respectively connected to one side of the two-color coupling spectroscopic grating.

3. The on-chip spectroscopic mid-infrared detection device according to claim 2, characterized in that: The first shielding structure and the second shielding structure are respectively provided, comprising: The first shielding structure covers the first transmission waveguide and the first mode spot conversion structure, and the second shielding structure covers the second mode spot conversion structure and the second transmission waveguide.

4. The on-chip spectroscopic mid-infrared detection device according to claim 2, characterized in that: The mid-infrared light comprises: an input wavelength including a 2-14 μm band of the mid-infrared light, and the input wavelength is vertically or obliquely incident on the mid-infrared light to the two-color coupling spectroscopic grating.

5. The on-chip spectroscopic mid-infrared detection device according to claim 1, characterized in that: The structure of the two-color coupled spectroscopic grating includes: a uniform periodic grating structure that meets the Bragg condition, and a non-uniform periodic grating structure optimized based on various inverse algorithms; wherein the non-uniform periodic grating structure includes: apodized gratings, two-dimensional gratings and other gratings with spectroscopic function.

6. The on-chip spectroscopic mid-infrared detection device according to claim 1, characterized in that: The refrigeration methods adopted by the first refrigeration structure and the second refrigeration structure include: liquid nitrogen refrigeration and semiconductor refrigeration.

7. An on-chip spectroscopic mid-infrared detection device, characterized in that: It comprises several groups of on-chip spectroscopic mid-infrared detection devices as described in any one of claims 1-6.

8. The on-chip spectroscopic mid-infrared detection device according to claim 7, characterized in that: Also includes: A plurality of groups of on-chip spectroscopic detection devices are arranged vertically on a substrate, and the wavelengths detected by the on-chip spectroscopic detection devices between the groups are the same or different.

9. An on-chip spectroscopic mid-infrared imaging method, characterized in that: The on-chip spectroscopic mid-infrared detection device as described in any one of claims 7-8 includes: obtaining intensity information of two or more wavelengths of imaging through mid-infrared two-color spectroscopic detection, and then fusing the images through a fusion algorithm to reconstruct imaging.

10. The on-chip spectroscopic mid-infrared imaging method according to claim 9, characterized in that: The method of obtaining the intensity information of two or more wavelengths of imaging by mid-infrared two-color spectroscopic detection includes: According to different wavelengths, the structural parameters of the two-color coupled spectroscopic grating are adjusted, and the structural parameters include: grating period, etching depth, and duty cycle.

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