Miniature spectral imaging chip and miniature imaging spectrometer

Abstract

The application relates to a miniature spectral imaging chip and a miniature imaging spectrometer, and belongs to the technical field of spectral imaging. The chip comprises, from top to bottom, an optical filtering layer, an image sensing layer and a signal processing layer. The optical filtering layer is composed of a transparent medium substrate and a plurality of different micro-nano structure units, each of which comprises a plurality of micro-nano structure arrays. The micro-nano structure arrays are single-layer or multi-layer structures. Each micro-nano structure unit covers a single or multiple photosensitive pixel units on a photodetector array layer. The area of the photodetector array layer covered by the micro-nano structure unit is a spectral chip area. The image sensing layer comprises the photodetector array layer and a metal circuit layer arranged on the photodetector array layer. The application realizes high spectral resolution and high image resolution in a very small volume.

Description

Technical Field

[0001] This invention belongs to the field of spectral imaging, and specifically relates to a miniature spectral imaging chip and a miniature imaging spectrometer. Background Technology

[0002] Image sensing has become a commonly used technology, utilized in a wide range of applications from webcams and smartphone cameras to autonomous vehicles and industrial inspection. With the development of machine vision and artificial intelligence, there is a growing focus on extending the dimensions of visual sensing technology. Therefore, building upon traditional image sensing technologies, the industry is actively developing new image sensor technologies to detect information beyond the range of human vision, including wider spectral ranges, more unique polarization characteristics, and higher spectral resolution.

[0003] In reality, current image sensors themselves cannot distinguish colors. Therefore, in applications, image sensors need to use color filter arrays. The most common type is the Bayer array filter, where different color blocks are arranged like a mosaic in the order of green-red-green-blue, so that each pixel under the "mosaic" senses a different color. Simply obtaining the red, green, and blue (RGB) light intensity values ​​at each pixel is insufficient to support the needs of more complex image sensing.

[0004] Imaging spectroscopy combines spectral and imaging techniques, integrating spectral and image resolution capabilities to achieve spatial spectral analysis, i.e., multispectral imaging and hyperspectral imaging. Currently, mainstream spectral imaging combines spectral analysis devices with grayscale image sensors, which limits the miniaturization of this technology. Summary of the Invention This application provides a miniature spectral imaging chip and a miniature imaging spectrometer to at least solve the above-mentioned technical problems existing in the prior art.

[0005] One embodiment of this application provides a miniature spectral imaging chip, which, from top to bottom, comprises an optical filtering layer, an image sensing layer, and a signal processing layer. The optical filtering layer is composed of a transparent dielectric substrate and several different micro / nano structure units, each of which contains multiple micro / nano structure arrays. The micro / nano structure arrays are single-layer or multi-layer structures. Each micro / nano structure unit covers one or more photosensitive pixel units on a photodetector array layer. The area of ​​the photodetector array layer covered by the micro / nano structure unit is the spectral chip area. The image sensing layer includes a photodetector array layer and a metal circuit layer disposed on the photodetector array layer. The photodetector array layer includes photosensitive pixel units and non-photosensitive areas. The metal structure units in the metal circuit layer are vertically aligned with the non-photosensitive areas. Some photosensitive pixel units in the photodetector array layer are aligned with the micro / nano structure units, while no micro / nano structure units are disposed above the photosensitive pixel units in other areas.

[0006] In one embodiment, the signal processing layer includes a signal processing circuit that is electrically connected to the image sensing layer.

[0007] In one embodiment, the non-photosensitive area includes a larger upper area and a smaller lower area, and is rectangular.

[0008] In one embodiment, the transparent dielectric substrate is made of one of silicon dioxide, magnesium fluoride, and aluminum oxide.

[0009] In one embodiment, the micro / nano structure array is a thin film, a graded bandgap material, a phase change material with tunable refractive index, a photonic crystal, or a metasurface structure.

[0010] In one embodiment, the shape of the micro / nano structure array is one or more of the following: cylinder, annular cylinder, nanopore, square nanopillar, square nanopore, cross-shaped nanopillar, cross-shaped nanopore, and triangular prism, and its specific arrangement and size are determined by the selected transmission wavelength.

[0011] In one embodiment, the material of the micro / nano structure array is one of silicon, germanium and its compounds, and chalcogenide materials.

[0012] In one embodiment, a light-concentrating metasurface lens is provided on the optical filter layer.

[0013] Another embodiment of this application provides a miniature imaging spectrometer, including any of the miniature spectral imaging chips described above.

[0014] In one embodiment, the optical filter layer is provided with a support structure layer, a transparent substrate is deposited on the support structure layer, and an imaging superlens is provided on the transparent substrate.

[0015] Compared with the prior art, this application has the following advantages: 1. The miniature spectral imaging chip in this application uses a metasurface filter layer to replace the Bayer array filter mirror. The metasurface optical filter layer is directly integrated on the CIS (CMOS image sensor) wafer and can be fabricated in one fabrication using CMOS technology, achieving both higher spectral resolution and image resolution in a very small volume.

[0016] 2. The fabrication process of the miniature spectral imaging chip in this application is simplified, which can reduce costs and improve device stability.

[0017] 3. The spectral chip area of ​​the miniature spectral imaging chip in this application outputs spectral information in real time. The non-spectral chip area has a greatly enhanced light-sensing performance because there is no filter structure above its photodetector. It can obtain higher quality real-time image information simultaneously. Finally, the spectral information and image information are integrated to obtain a high-fidelity spectral image. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 2 of this application; Figure 3 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 3 of this application; Figure 4 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 4 of this application; Figure 5 This is a schematic diagram showing that each micro / nano structure unit covers multiple photosensitive pixel units in Embodiment 2 of this application; Figure 6 This is a schematic diagram showing each micro / nano structure unit covering a single photosensitive pixel unit in embodiments 1, 3, and 4 of this application; Figure 7 This is a schematic diagram illustrating another possible distribution of the spectral chip region in Embodiments 1-4 of this application; Figure 8 This is a schematic diagram showing the distribution of the array of spectral chip regions in Embodiments 1-4 of this application; Figure 9 This is a schematic diagram of the arrangement of micro-nano structure arrays in the micro-nano structure units in Embodiments 1-4 of this application (including but not limited to); Figure 10 This is a schematic diagram of the miniature spectral imaging chip integrating a focusing superlens in Embodiment 5 of this application; Figure 11 This is a schematic diagram of the miniature imaging spectrometer in Application Example 1 of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Optical filtering layer; 11. Transparent dielectric substrate; 12. Micro / nano structure unit; 121. Micro / nano structure array; 2. Image sensor; 21. Photodetector array layer; 211. Photosensitive pixel unit; 212. Non-photosensitive area; 22. Metal circuit layer; 221. Metal structural unit; 3. Signal processing layer; 6. Support structure layer; 7. Imaging superlens; 8. Focusing metasurface lens. Detailed Implementation

[0020] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Example 1 Figure 1 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 1 of this application.

[0022] Reference Figure 1 This application provides a miniature spectral imaging chip, which includes, from top to bottom, an optical filtering layer 1, an image sensing layer 2, and a signal processing layer 3. The optical filtering layer 1 is composed of a transparent dielectric substrate 11 and several different micro / nano structural units 12, and the transparent dielectric substrate 11 is deposited on the image sensing layer 2.

[0023] Each micro / nanostructure unit 12 comprises multiple micro / nanostructure arrays 121. The micro / nanostructure arrays 121 can be single-layer or multi-layer structures. In this embodiment, the micro / nanostructure arrays 121 are single-layer structures, and their structural forms can be thin films, graded bandgap materials, phase change materials with tunable refractive indices, photonic crystals, or metasurface structures. The shapes of the micro / nanostructure arrays 121 can be cylinders, annular pillars, nanopores, square nanopillars, square nanopores, cross-shaped nanopillars, cross-shaped nanopores, triangular prisms, etc. Their materials include, but are not limited to, silicon, germanium, and their compounds, such as silicon nitride, silicon dioxide, titanium oxide, and various chalcogenide materials. The transparent dielectric substrate 11 is made of one of silicon dioxide, magnesium fluoride, and aluminum oxide.

[0024] Figure 9 The figure shows a schematic diagram of the shape of the micro / nano structure array 121 according to this embodiment (including but not limited to).

[0025] The pattern sensing layer 2 includes a photodetector array layer 21 and a metal circuit layer 22 disposed on the photodetector array layer 21. In this embodiment, the pattern sensor 2 is back-illuminated, with the photodetector array layer 21 on top and the metal circuit layer 22 on the bottom.

[0026] The photodetector array layer 21 includes photosensitive pixel units 211 and non-photosensitive regions 212. Metal structure units 221 in the metal circuit layer are vertically aligned with the non-photosensitive regions 212. Some photosensitive pixel units 211 in the photodetector array layer 21 are directly opposite the micro / nano structure units 12, while the remaining photosensitive pixel units 211 are not positioned above the micro / nano structure units 12. The non-photosensitive regions 212 are larger at the top and smaller at the bottom.

[0027] Reference Figure 1 and Figure 6 A portion of the photodetector array layer 21 is directly above the micro / nano structure unit 12, and each micro / nano structure unit 12 covers a single photosensitive pixel unit 211 on the photodetector array layer 21. The area of ​​the photodetector array layer 21 covered by the micro / nano structure unit 12 is the spectral chip region.

[0028] Figure 8 The illustration shows a schematic diagram of yet another modified embodiment of the spectral chip region according to an embodiment of this application. For example... Figure 8 As shown, in this modified embodiment, the micro / nano structure unit 12 is formed on the upper surface of the image sensing layer 2.

[0029] The signal processing layer 3 contains a signal processing circuit, which is connected to the image sensing layer via electrical contacts. The signal processing circuit obtains the intensity S(n) of the signal response of the incident light reaching the photosensitive surface after passing through the optical filter layer. Combined with the pre-calibrated transmission characteristic spectra A(λ,n) of each micro / nano structural unit 12, the incident spectral information is calculated and restored. The spectral chip area outputs spectral information in real time, while the non-spectral chip area synchronously acquires real-time image information. Finally, the spectral information and image information are integrated to obtain a high-fidelity spectral image.

[0030] Example 2 Figure 2 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 2 of this application.

[0031] Reference Figure 2 This application provides a miniature spectral imaging chip, which includes, from top to bottom, an optical filtering layer 1, an image sensing layer 2, and a signal processing layer 3. The optical filtering layer 1 is composed of a transparent dielectric substrate 11 and several different micro / nano structural units 12, and the transparent dielectric substrate 11 is deposited on the image sensing layer 2.

[0032] Each micro / nanostructure unit 12 comprises multiple micro / nanostructure arrays 121. The micro / nanostructure arrays 121 can be single-layer or multi-layer structures. In this embodiment, the micro / nanostructure arrays 121 are single-layer structures, and their structural forms can be thin films, graded bandgap materials, phase change materials with tunable refractive indices, photonic crystals, or metasurface structures. The shapes of the micro / nanostructure arrays 121 can be cylinders, annular pillars, nanopores, square nanopillars, square nanopores, cross-shaped nanopillars, cross-shaped nanopores, triangular prisms, etc. Materials include, but are not limited to, silicon, germanium, and their compounds, such as silicon nitride, silicon dioxide, titanium oxide, and various chalcogenide materials. The transparent dielectric substrate 11 is made of one of silicon dioxide, magnesium fluoride, and aluminum oxide.

[0033] The pattern sensing layer 2 includes a photodetector array layer 21 and a metal circuit layer 22 disposed on the photodetector array layer 21. In this embodiment, the pattern sensor 2 is back-illuminated, with the photodetector array layer 21 on top and the metal circuit layer 22 on the bottom.

[0034] The photodetector array layer 21 includes photosensitive pixel units 211 and non-photosensitive areas 212. Metal structure units 221 in the metal circuit layer are vertically aligned with the non-photosensitive areas 212. Some photosensitive pixel units 211 in the photodetector array layer 21 are directly opposite the micro / nano structure units 12, while the remaining photosensitive pixel units 211 are not positioned above the micro / nano structure units 12. The non-photosensitive areas 212 are rectangular.

[0035] Reference Figure 2 and Figure 5 A portion of the photodetector array layer 21 is directly above the micro / nano structure unit 12, and each micro / nano structure unit 12 covers multiple photosensitive pixel units 211 on the photodetector array layer 21. The photodetector array layer 21 covered by the micro / nano structure unit 12 is a spectral chip region.

[0036] Figure 7 The illustration shows a schematic diagram of yet another modified embodiment of the spectral chip region according to an embodiment of this application. For example... Figure 7 As shown, in this modified embodiment, the micro / nano structure unit 12 is formed on the upper surface of the image sensing layer 2.

[0037] The signal processing layer 3 contains a signal processing circuit, which is connected to the image sensing layer via electrical contacts. The signal processing circuit obtains the intensity S(n) of the signal response of the incident light reaching the photosensitive surface after passing through the optical filter layer. Combined with the pre-calibrated transmission characteristic spectra A(λ,n) of each micro / nano structural unit 12, the incident spectral information is calculated and restored. The spectral chip area outputs spectral information in real time, while the non-spectral chip area synchronously acquires real-time image information. Finally, the spectral information and image information are integrated to obtain a high-fidelity spectral image.

[0038] Example 3 Figure 3 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 3 of this application.

[0039] Reference Figure 3 This application provides a miniature spectral imaging chip, which includes, from top to bottom, an optical filtering layer 1, an image sensing layer 2, and a signal processing layer 3. The optical filtering layer 1 is composed of a transparent dielectric substrate 11 and several different micro / nano structural units 12, and the transparent dielectric substrate 11 is deposited on the image sensing layer 2.

[0040] Each micro / nanostructure unit 12 comprises multiple micro / nanostructure arrays 121. The micro / nanostructure arrays 121 can be single-layer or multi-layer structures. In this embodiment, the micro / nanostructure arrays 121 are single-layer structures, and their structural forms can be thin films, graded bandgap materials, phase change materials with tunable refractive indices, photonic crystals, or metasurface structures. The shapes of the micro / nanostructure arrays 121 can be cylinders, annular pillars, nanopores, square nanopillars, square nanopores, cross-shaped nanopillars, cross-shaped nanopores, triangular prisms, etc. Materials include, but are not limited to, silicon, germanium, and their compounds, such as silicon nitride, silicon dioxide, titanium oxide, and various chalcogenide materials. The transparent dielectric substrate 11 is made of one of silicon dioxide, magnesium fluoride, and aluminum oxide.

[0041] The pattern sensing layer 2 includes a photodetector array layer 21 and a metal circuit layer 22 disposed on the photodetector array layer 21. In this embodiment, the pattern sensor 2 is a front-illuminated type, with the metal circuit layer 22 on top and the photodetector array layer 21 on the bottom.

[0042] The photodetector array layer 21 includes photosensitive pixel units 211 and non-photosensitive areas 212. Metal structure units 221 in the metal circuit layer are vertically aligned with the non-photosensitive areas 212. Some photosensitive pixel units 211 in the photodetector array layer 21 are directly opposite the micro / nano structure units 12, while the remaining photosensitive pixel units 211 are not positioned above the micro / nano structure units 12. The non-photosensitive areas 212 are rectangular.

[0043] Reference Figure 3 and Figure 6 A portion of the photodetector array layer 21 is directly above the micro / nano structure unit 12, and each micro / nano structure unit 12 covers a single photosensitive pixel unit 211 on the photodetector array layer 21. The photodetector array layer 21 covered by the micro / nano structure unit 12 is a spectral chip region.

[0044] The signal processing layer 3 contains a signal processing circuit, which is connected to the image sensing layer 2 via electrical contacts. The signal processing circuit obtains the intensity S(n) of the signal response of the incident light reaching the photosensitive surface after passing through the optical filter layer 1. Combined with the pre-calibrated transmission characteristic spectra A(λ,n) of each micro / nano structural unit 12, the incident spectral information is calculated and restored. The spectral chip area outputs spectral information in real time, while the non-spectral chip area synchronously acquires real-time image information. Finally, the spectral information and image information are integrated to obtain a high-fidelity spectral image.

[0045] Example 4 Figure 4 This is a schematic diagram of the structure of the miniature spectral imaging chip in Embodiment 4 of this application.

[0046] Reference Figure 4 This application provides a miniature spectral imaging chip, which includes, from top to bottom, an optical filtering layer 1, an image sensing layer 2, and a signal processing layer 3. The optical filtering layer 1 is composed of a transparent dielectric substrate 11 and several different micro / nano structural units 12, and the transparent dielectric substrate 11 is deposited on the image sensing layer 2.

[0047] Each micro / nanostructure unit 12 comprises multiple micro / nanostructure arrays 121. The micro / nanostructure arrays 121 can be single-layer or multi-layer structures. In this embodiment, the micro / nanostructure arrays 121 are multi-layer structures, and their structural forms can be thin films, graded bandgap materials, phase change materials with tunable refractive indices, photonic crystals, or metasurface structures. The shapes of the micro / nanostructure arrays 121 can be cylinders, annular pillars, nanopores, square nanopillars, square nanopores, cross-shaped nanopillars, cross-shaped nanopores, triangular prisms, etc. Their materials include, but are not limited to, silicon, germanium, and their compounds, such as silicon nitride, silicon dioxide, titanium oxide, and various chalcogenide materials. The transparent dielectric substrate 11 is made of one of silicon dioxide, magnesium fluoride, and aluminum oxide.

[0048] The pattern sensing layer 2 includes a photodetector array layer 21 and a metal circuit layer 22 disposed on the photodetector array layer 21. In this embodiment, the pattern sensor 2 is back-illuminated, with the photodetector array layer 21 on top and the metal circuit layer 22 on the bottom.

[0049] The photodetector array layer 21 includes photosensitive pixel units 211 and non-photosensitive areas 212. Metal structure units 221 in the metal circuit layer are vertically aligned with the non-photosensitive areas 212. Some photosensitive pixel units 211 in the photodetector array layer 21 are directly opposite the micro / nano structure units 12, while the remaining photosensitive pixel units 211 are not positioned above the micro / nano structure units 12. The non-photosensitive areas 212 are rectangular.

[0050] Reference Figure 4 and Figure 6A portion of the photodetector array layer 21 is directly above the micro / nano structure unit 12, and each micro / nano structure unit 12 covers a single photosensitive pixel unit 211 on the photodetector array layer 21. The photodetector array layer 21 covered by the micro / nano structure unit 12 is a spectral chip region.

[0051] The signal processing layer 3 contains a signal processing circuit, which is connected to the image sensing layer via electrical contacts. The signal processing circuit obtains the intensity S(n) of the signal response of the incident light reaching the photosensitive surface after passing through the optical filter layer. Combined with the pre-calibrated transmission characteristic spectra A(λ,n) of each micro / nano structural unit 12, the incident spectral information is calculated and restored. The spectral chip area outputs spectral information in real time, while the non-spectral chip area synchronously acquires real-time image information. Finally, the spectral information and image information are integrated to obtain a high-fidelity spectral image.

[0052] Example 5 Figure 10 This is a schematic diagram of the miniature spectral imaging chip integrating a focusing superlens in Embodiment 5 of this application.

[0053] Reference Figure 10 This application also provides a miniature imaging spectrometer, which, from top to bottom, includes an optical filtering layer 1, an image sensing layer 2, and a signal processing layer 3. The optical filtering layer 1 has a focusing metasurface lens 8, which can be positioned above or below the optical filtering layer; in this embodiment, the metasurface lens 8 is positioned above the optical filtering layer 1. The optical filtering layer 1 can be a single-layer or multi-layer structure. Figure 10 The diagram shows a single-layer structure.

[0054] The image sensor 2 includes a photodetector array layer 21 and a metal circuit layer 22 disposed on the photodetector array layer 21. The photodetector array layer 21 is located below or above the metal circuit layer 22. In this embodiment, the image sensor 2 is a back-illuminated type, with the photodetector array layer 21 on top and the metal circuit layer 22 below.

[0055] The difference between this embodiment and Embodiment 1 is that the spectral imaging chip further integrates a focusing metasurface lens 8. The focusing metasurface lens 8 is positioned above the optical filter layer 1. Utilizing the light-converging capability of the focusing metasurface lens 8, it replaces the traditional microlens array, improving the photosensitive surface's ability to receive incident light. Simultaneously, the ultra-thin characteristics of the metasurface and its compatibility with semiconductor materials ensure that this further processing method does not compromise the overall integrity of the aforementioned micro-spectral imaging chip, nor does it significantly increase its size. Both the optical filter layer 1 and the focusing metasurface lens 8 are directly fabricated on the wafer-level image sensor, forming a unified spectral imaging chip.

[0056] Application Example 1 Figure 11 This is a schematic diagram of the structure of the miniature imaging spectrometer in Application Embodiment 1 of this application.

[0057] Reference Figure 11 This application also provides a miniature imaging spectrometer, which includes an imaging superlens 7, an optical filter layer 1, an image sensing layer 2, and a signal processing layer 3. The imaging superlens 7 can be disposed above or below the optical filter layer 1; in this embodiment, the imaging superlens 7 is disposed above the optical filter layer 1. The optical filter layer 1 has a single-layer or multi-layer structure. Figure 11 The diagram shows a single-layer structure.

[0058] The image sensor 2 includes a photodetector array layer 21 and a metal circuit layer 22 disposed on the photodetector array layer 21. The photodetector array layer 21 is located below or above the metal circuit layer 22. In this embodiment, the image sensor 2 is a back-illuminated type, with the photodetector array layer 21 on top and the metal circuit layer 22 below.

[0059] To enable the imaging superlens 7 to image onto the image sensing layer 2, a support structure layer 6 is provided between the imaging superlens 7 and the optical filter layer 1, ensuring that the distance between the imaging superlens 7 and the image sensing layer 2 meets the optical back focal length requirement. The fabrication process is as follows: A support structure layer 6 of a certain thickness is fabricated above the optical filter layer 1. A transparent substrate 11 is then deposited on the support structure layer 6 to fabricate the imaging superlens 7. During the design of the imaging superlens 7, the formulas for metasurface focal length and phase distribution are used: Where x and y are the hyperatom coordinates of the wide-angle superlens. Let λ be the incident angle of the obliquely incident beam with respect to the x-axis and y-axis, f be the focal length of the designed wide-angle superlens, and λ be the wavelength of the incident light. , .

[0060] The phase distribution at various locations on the metasurface is calculated, and the size radius of the micro / nano structures at each location is determined by combining the correspondence between the micro / nano structure size and the phase. The metasurface structure is then etched using photolithography in transparent materials (such as silicon nitride, amorphous silicon, titanium dioxide, and various chalcogenide materials) in the visible and near-infrared bands, enabling a miniature imaging spectrometer that highly integrates a short-focal-length imaging super-lens with an imaging chip.

[0061] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0062] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A miniature spectral imaging chip, characterized in that: The miniature spectral imaging chip comprises, from top to bottom, an optical filtering layer, an image sensing layer, and a signal processing layer. The optical filtering layer consists of a transparent substrate and several different micro / nano structure units, each containing multiple micro / nano structure arrays. These micro / nano structure arrays are single-layer or multi-layer structures. Each micro / nano structure unit covers one or more photosensitive pixel units on the image sensing layer. The image sensing layer area covered by the micro / nano structure unit is the spectral chip area. The image sensing layer includes a photodetector array layer and a metal circuit layer disposed on the photodetector array layer. The photodetector array layer includes photosensitive pixel units and non-photosensitive areas. The metal structure units in the metal circuit layer are vertically aligned with the non-photosensitive areas. The non-photosensitive areas include those that are larger at the top and smaller at the bottom, and those that are rectangular in shape. In one embodiment, the remaining photosensitive pixel units located outside the coverage area of ​​the micro / nano structure unit constitute a non-spectral chip area. Some photosensitive pixel units in the photodetector array layer face the micro / nano structure unit, while no micro / nano structure unit is placed above the photosensitive pixel units in the remaining area. The signal processing layer includes a signal processing circuit, which is connected to the image sensing layer via electrical contacts. The signal processing circuit can obtain the intensity result S(n) of the signal response of the incident light reaching the photosensitive surface after passing through the optical filter layer. Combined with the transmission characteristic spectrum A(λ,n) of each micro / nano structure unit that has been pre-calibrated, the incident spectral information is calculated and restored. The spectral chip area outputs spectral information in real time, and the non-spectral chip area can synchronously obtain real-time image information. Finally, the spectral information and image information are integrated to obtain a high-fidelity spectral image.

2. The miniature spectral imaging chip according to claim 1, characterized in that: The transparent dielectric substrate is made of one of the following materials: silicon dioxide, magnesium fluoride, and aluminum oxide.

3. The miniature spectral imaging chip according to claim 1, characterized in that: The micro / nano structure array is a thin film, a graded bandgap material, a phase change material with adjustable refractive index, a photonic crystal, or a metasurface structure.

4. A miniature spectral imaging chip according to claim 1, characterized in that: The shape of the micro / nano structure array is one or more of the following: cylinder, annular cylinder, nanopore, square nanopillar, square nanopore, cross-shaped nanopillar, cross-shaped nanopore, and triangular prism. Its specific arrangement and size are determined by the selected transmission wavelength.

5. A miniature spectral imaging chip according to claim 4, characterized in that: The material of the micro / nano structure array is one of silicon, germanium and its compounds, and chalcogenide materials.

6. A miniature spectral imaging chip according to claim 1, characterized in that: A light-concentrating metasurface lens is provided on the optical filter layer.

7. A miniature imaging spectrometer, characterized in that: Includes any one of the miniature spectral imaging chips according to claims 1-5.

8. A miniature imaging spectrometer according to claim 7, characterized in that: The optical filter layer has a support structure layer, a transparent substrate is deposited on the support structure layer, and an imaging superlens is disposed on the transparent substrate.

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