A spectral chip and a spectral camera comprising the same

Abstract

The application relates to a spectrum chip and a spectrum camera comprising the same. The spectrum chip comprises: a silicon-based substrate provided with an image sensing layer; a base material layer arranged on the image sensing layer; and a spectrum modulation material layer arranged on the base material layer, wherein the spectrum modulation material layer comprises a plurality of filter units arranged in an array, each filter unit comprising a plurality of filter subunits having different transmittance curves, and wherein light incident on the spectrum chip is jointly modulated by the spectrum modulation material layer and the base material layer.

Description

Technical Field

[0001] This application relates to the field of spectral modulation technology, specifically to a spectral chip and a spectral camera containing the same. Background Technology

[0002] Spectral imaging has seen rapid development in recent years, enriching traditional imaging methods and providing unprecedented detail of objects. As a high-dimensional perception method, it plays an increasingly important role in fields such as precision agriculture, food safety inspection, environmental monitoring, and medical imaging.

[0003] Imaging spectral chips are crucial components of spectral imaging detection systems, enabling both two-dimensional imaging of targets and the detection of their spectral information. Current imaging spectral chip development primarily employs different technological approaches, such as metamaterial spectral modulation and thin-film material spectral modulation. The metamaterial spectral modulation approach utilizes periodic porous nanostructure arrays of varying sizes on a dielectric film to achieve narrowband filtering of the target image across multiple spectral bands. However, this approach suffers from practical problems in applications, including small half-width at half-maximum (HWHM) of the transmission spectrum, low energy efficiency, reduced spatial resolution, complex fabrication processes, and high costs, making it unsuitable for everyday applications. The thin-film material spectral modulation approach, on the other hand, involves forming a periodic structure of a single-layer filter film on a photoelectric conversion substrate. Each periodic unit includes multiple modulation channels made of different spectral modulation materials, thereby achieving spectral dispersion, as disclosed in CN113497065A and CN119437431A.

[0004] However, due to the limitations of the material itself, the transmittance curve of the modulation channel cannot achieve a better linear response in certain key wavelength ranges (key bands, such as the 500-650nm range in cameras used for visible light imaging). When reproducing colors, the response of such a structure to the key band will be affected by bands outside that band, especially under low light conditions, which will make it impossible to provide accurate spectral capture. Utility Model Content

[0005] In view of the problems existing in the prior art, the purpose of this application is to provide a spectral chip and a spectral camera containing the same.

[0006] Specifically, in a first aspect of this application, a spectral chip is provided, comprising:

[0007] A silicon-based substrate with an image sensing layer disposed thereon;

[0008] A base material layer is disposed on the image sensing layer;

[0009] A spectral modulation material layer is disposed on the base material layer, wherein the spectral modulation material layer comprises multiple filter units arranged in an array, and each filter unit comprises multiple filter sub-units with different transmittance curves.

[0010] In this process, the light incident on the spectral chip is modulated by both the spectral modulation material layer and the base material layer.

[0011] Optionally, the base material layer has a first transmittance curve, wherein the shape of the first transmittance curve is designed such that the transmittance curve of the light incident on the spectral chip after being modulated by the spectral modulation material layer and the base material layer is more sensitive in a preset wavelength range than in a response outside the preset wavelength range.

[0012] Optionally, the transmittance of the first transmittance curve within a preset wavelength range is higher than the transmittance outside the preset wavelength range.

[0013] Optionally, if the waveform of the filter subunit is plateau-shaped within the preset wavelength range, the final transmittance curve after modulation will show a peak within the preset wavelength range; or

[0014] If the waveform of the filter subunit has a peak within the preset wavelength range, and the final transmittance curve after modulation still shows a peak within the preset wavelength range, the full width at half maximum (FWHM) of the modulated peak is smaller than that of the peak before modulation; or

[0015] If the waveform of the filter subunit is concave within the preset wavelength range, the final transmittance curve after modulation will show a peak within the preset wavelength range.

[0016] Optionally, the base material layer is a colloidal curable film composed of a mixture of resin material, photoinitiator material, and solvent material; and / or

[0017] The filter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment, and solvent material.

[0018] Optionally, the base material layer is a single-layer structure.

[0019] Optionally, throughout the entire spectral chip, the sum of the thicknesses of each filter subunit and its corresponding base material layer in projection relation is equal; and

[0020] Within the same filter unit, the thickness of the base material layer corresponding to different filter sub-units is stepped.

[0021] Optionally, the base material layer includes:

[0022] A mesh structure formed of a dielectric material, wherein the orthographic projection of each mesh of the mesh structure onto the image sensing layer is aligned with the orthographic projection of one or more filter subunits onto the image sensing layer;

[0023] The base material is filled into the mesh, wherein the base material is the same in each mesh.

[0024] Optionally, the base material in each mesh of the mesh structure corresponds to a filter sub-unit, wherein the sum of the thicknesses of the base materials in all meshes and their corresponding filter sub-units is equal throughout the entire spectral chip; and within the same filter unit, the thicknesses of the base materials corresponding to different filter sub-units are stepped.

[0025] Optionally, the thickness of the filter subunit is in the range of 500-1000 nm, and the thickness of the base material layer is in the range of 50-500 nm.

[0026] Optionally,

[0027] The preset wavelength range is 500-650nm;

[0028] The first transmittance curve satisfies the following constraints: peak transmittance wavelength is 500-640nm, T(400nm-490nm)≥70%, T(585nm-620nm)≥90%, T(650nm-900nm)≥70%;

[0029] The filter unit comprises 3*3 filter sub-units C1-C9, and the transmittance curves of the filter sub-units satisfy the following constraints:

[0030] TC1: Valley transmittance wavelength is 420-465nm, T(420nm-465nm)≤20%, T(515nm-900nm)≥80%;

[0031] TC2: Valley transmittance wavelength is 470-500nm, T(470nm-500nm)≤10%, T(525nm-900nm)≥90%;

[0032] TC3: Valley transmittance wavelength is 510-560nm, T(400nm-450nm)≥80%, T(510nm-560nm)≤20%; T(580nm-900nm)≥85%;

[0033] TC4: Valley transmittance wavelength is 585-615nm, T(415nm-480nm)≥80%, T(585nm-615nm)≤10%; T(650nm-900nm)≥75%;

[0034] TC5: Valley transmittance wavelength is 620-645nm, T(300nm-540nm) ≥80%, T(620nm-645nm) ≤10%; T(675nm-900nm) ≥85%;

[0035] TC6: Valley transmittance wavelength is 625-660nm, T(400nm-535nm) ≥80%, T(625nm-660nm) ≤10%; T(690nm-900nm) ≥85%;

[0036] TC7: Valley transmittance wavelength is 655-700nm; T(400nm-545nm) ≥80%; T(655nm-700nm) ≤20%; T(740nm-900nm) ≥85%;

[0037] TC8: Valley transmittance wavelength is 685-730nm, T(400nm-565nm) ≥80%, T(685nm-730nm) ≤10%; T(780nm-900nm) ≥85%;

[0038] TC9: Valley transmittance wavelength is 700-745nm, T(470nm-590nm) ≥80%, T(700nm-745nm) ≤40%; T(790nm-900nm) ≥80%;

[0039] The transmittance curves of the light incident on the spectral chip, after being modulated by the spectral modulation material layer and the base material layer, respectively satisfy the following constraints:

[0040] TA1: Peak transmittance wavelength is 500nm-650nm, T(430nm-460nm)≤10%, T(500nm-650nm)≥60%, T(650nm-900nm)≥55%;

[0041] TA2: Peak transmittance wavelength is 550-620nm, T(460nm-500nm)≤10%, T(550nm-620nm)≥80%, T(650nm-900nm)≥65%;

[0042] TA3: Peak transmittance wavelength is 575-635nm, T(510nm-550nm)≤15%, T(575nm-635nm)≥70%, T(650nm-900nm)≥60%;

[0043] TA4: Valley transmittance wavelength is 550-620nm, T(400nm-540nm)≥20%, T(550nm-620nm)≤20%, T(640nm-900nm)≥55%;

[0044] TA5: Valley transmittance wavelength is 615-650nm, T(300nm-565nm) ≥60%, T(615nm-650nm) ≤20%, T(675nm-900nm) ≥60%;

[0045] TA6: Valley transmittance wavelength is 600-670nm, T(400nm-560nm) ≥60%, T(600nm-670nm) ≤20%, T(700nm-900nm) ≥60%;

[0046] TA7: Valley transmittance wavelength is 630-700nm, T(400nm-575nm) ≥60%, T(630nm-700nm) ≤20%, T(735nm-900nm) ≥60%;

[0047] TA8: Valley transmittance wavelength is 635-735nm, T(400nm-590nm) ≥60%, T(635nm-735nm) ≤20%, T(780nm-900nm) ≥60%;

[0048] TA9: Peak transmittance wavelength is 500-625nm, T(300nm-480nm)≤60%, T(500nm-625nm)≥60%, T(685nm-750nm)≤40%, T(810nm-900nm)≥60%.

[0049] Optionally, there is at least one inclined overlap region relative to the silicon substrate between each filter subunit and its adjacent filter subunit, the orthographic projection of the inclined overlap region on the silicon substrate spanning two adjacent pixels on the image sensing layer.

[0050] Optionally, the filter subunit is frustum-shaped.

[0051] Optionally, two adjacent filter subunits are respectively a regular square frustum and an inverted square frustum.

[0052] Optionally, the angle between the beveled overlap area and the silicon substrate is between 60 degrees and 90 degrees.

[0053] Optionally, each filter unit includes 3*3 filter subunits C1-C9, wherein the first row along the first direction consists of C1-C3, the second row along the first direction consists of C4-C6, and the third row along the first direction consists of C7-C9, wherein C2, C4, C6 and C8 are regular square frustums, and C1, C3, C5, C7 and C9 are inverted square frustums.

[0054] Optionally, the preset wavelength range is 500-650nm;

[0055] The first transmittance curve satisfies the following constraints: peak transmittance wavelength is 500-640nm, T(400nm-490nm)≥70%, T(585nm-620nm)≥90%, T(650nm-900nm)≥70%;

[0056] The transmittance curve of light incident on the multispectral chip, modulated by the spectral modulation material layer and the base material layer, satisfies the following constraint:

[0057] TA1: Peak transmittance wavelength is 520-640nm; T(420nm-495nm)≤10%; T(580nm-625nm)≥55%; T(670nm-900nm)≥50%;

[0058] TA2: Peak transmittance wavelength is 570-645nm; T(425nm-550nm) ≤10%; T(600nm-630nm) ≥70%; T(670nm-900nm) ≥55%;

[0059] TA3: Peak transmittance wavelength is 575-645nm; T(460nm-555nm)≤15%; T(580nm-620nm)≥70%; T(660nm-900nm)≥55%;

[0060] TA4: Valley transmittance wavelength is 550-650nm; T (400nm-500nm) ≥ 45%; T (580nm-645nm) ≤ 10%; T (700nm-900nm) ≥ 50%;

[0061] TA5: Valley transmittance wavelength is 550-675nm; T(425nm-500nm) ≥35%; T(550nm-665nm) ≤10%; T(700nm-900nm) ≥45%;

[0062] TA6: Valley transmittance wavelength is 500-650nm; T(350nm-450nm)≤40%; T(485nm-615nm)≥50%; T(800nm-900nm)≥60%;

[0063] TA7: Valley transmittance wavelength is 575-750nm; T(400nm-570nm) ≥45%; T(630nm-730nm) ≤10%; T(775nm-900nm) ≥50%;

[0064] TA8: Valley transmittance wavelength is 600-750nm; T(460nm-565nm)≥40%; T(620nm-745nm)≤10%; T(800nm-900nm)≥45%;

[0065] TA9: Valley transmittance wavelength is 600-760nm; T(460nm-580nm)≥50%; T(635nm-645nm)≤15%; T(800nm-900nm)≥50%.

[0066] A second aspect of this application provides a spectral camera, including the spectral chip described in the first aspect.

[0067] A third aspect of this application provides a method for fabricating a spectral chip, comprising:

[0068] An image sensing layer is formed on a silicon substrate;

[0069] A base material layer is formed on the image sensing layer;

[0070] A spectral modulation material layer is formed on the base material layer. The spectral modulation material layer includes multiple filter units arranged in an array. Each filter unit includes multiple filter sub-units. Each filter sub-unit, its corresponding base material layer region in projection relationship, and the pixel region of the image sensing layer constitute a spectral modulation channel.

[0071] The optical signal incident on the spectral chip is modulated by the spectral modulation material layer and the base material layer.

[0072] Optionally, forming a base material layer on the image sensing layer and forming a spectral modulation material layer on the base material layer includes:

[0073] A base material is formed on the image sensing layer;

[0074] The first filter sub-unit material of each filter unit is formed on the base material;

[0075] The first filter subunit material is patterned, wherein the patterned first filter subunit is cuboid, and during this process, the base material except for the base material at the position of the first filter subunit to be formed is cleaned and thinned to a first preset thickness.

[0076] The i+1th filter unit material in each filter unit is formed on the patterned i-th filter unit material and the thinned base material;

[0077] The material of the (i+1)th filter subunit is patterned, wherein the patterned (i+1)th filter subunit is a cuboid, and during this process, the base material other than the base material at the position of the (i+1)th filter subunit to be formed and the base material at the positions of the first to the i-th filter subunits that have been formed is cleaned and thinned to the (i+1)th preset thickness, wherein the (i+1)th filter subunit is adjacent to the i-th filter subunit, i traverses from 1 to n, and n is the total number of filter subunits included in each filter unit.

[0078] Optionally, in the entire spectral chip, the sum of the thickness of each filter subunit and the thickness of its corresponding base material in the projection relationship is equal; and in the same filter unit, the thickness of the base material corresponding to different filter subunits is stepped, with the thickness of the base material corresponding to the filter subunits fabricated earlier being larger.

[0079] Optionally, before forming a base material layer on the image sensing layer, the method further includes:

[0080] A dielectric material is formed on the image sensing layer;

[0081] The medium material is patterned to form a grid structure, wherein the orthographic projection of each mesh of the grid structure onto the image sensing layer is aligned with the orthographic projection of one or more filter sub-units to be formed onto the image sensing layer.

[0082] Optionally, the base material in each mesh of the mesh structure corresponds to a filter sub-unit, wherein the sum of the thicknesses of the base materials in all meshes and their corresponding filter sub-units is equal throughout the entire spectral chip; and within the same filter unit, the thicknesses of the base materials corresponding to different filter sub-units are stepped, with the base material corresponding to the filter sub-units fabricated earlier having a larger thickness.

[0083] Optionally, forming a base material layer on the image sensing layer and forming a spectral modulation material layer on the base material layer includes:

[0084] A base material is formed on the image sensing layer;

[0085] The base material is heated and cured to the desired hardness;

[0086] The first filter sub-unit material of each filter unit is formed on the base material;

[0087] The material of the first filter subunit is patterned, wherein the patterned first filter subunit is in the shape of a regular square frustum;

[0088] The j-th filter unit material in each filter unit is formed on the patterned i-th filter unit material and the exposed base material;

[0089] The material of the j-th filter subunit is patterned, wherein the patterned j-th filter subunit is a regular square frustum, wherein i and j traverse from 1 to n and the i-th filter subunit and the j-th filter subunit are not adjacent in physical space, and n is the total number of filter subunits included in each filter unit.

[0090] The areas of the base material exposed outside the areas forming all the filter sub-units in the shape of a regular square frustum are filled with the remaining filter sub-unit materials to form each filter sub-unit. In the same filter sub-unit, two adjacent filter sub-units are a combination of a regular square frustum and an inverted square frustum, and the two form a sloping overlapping area.

[0091] In this application, by introducing a base material layer with a transmittance curve designed for the target wavelength range, the transmittance curve of the original optical modulation subunit is modulated. This optimizes the response of the spectral camera to the target wavelength range, improves image quality, and reduces interference from bands outside the critical band (the presence of the base material layer reduces the light transmittance of bands outside the critical band, making the spectral chip more sensitive to the light response of the critical band), ensuring accurate color reproduction during shooting. Furthermore, the fabrication process of the base material layer is fully compatible with that of the optical modulation layer, achieving spectral modulation optimization of the spectral chip for the target wavelength range in a more economical way. Further, in a preferred embodiment, through the selection and thickness matching of the base material layer and the optical modulation material layer, the two work together to more finely modulate the transmittance curve of the optical modulation subunit, ultimately resulting in an ideal transmittance curve for the spectral chip. Attached Figure Description

[0092] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the drawings are used to denote similar components, wherein:

[0093] Figure 1 This is a schematic diagram of the structure of a spectral chip based on existing technology;

[0094] Figure 2 It is based on the light transmittance curve of a 9-channel spectral chip using existing technology;

[0095] Figure 3This is a schematic diagram of the structure of a spectral chip according to an embodiment of this application;

[0096] Figure 4 This is a light transmittance curve of the base material layer according to an embodiment of this application;

[0097] Figure 5 This is a light transmittance curve of a structure having a base material layer according to an embodiment of this application after modulation;

[0098] Figure 6 (a) and (b) are schematic diagrams of a preferred structure of a spectral chip according to an embodiment of this application;

[0099] Figure 7 Is Figure 2 The diagram shown illustrates the presence of an aliasing region in the light transmittance curve.

[0100] Figure 8 Is Figure 5 The diagram shown illustrates the presence of an aliasing region in the light transmittance curve.

[0101] Figure 9 (a) and (b) are schematic diagrams of a preferred structure of a spectral chip according to another embodiment of this application;

[0102] Figure 10 It is based on Figure 9 A partial schematic diagram of the structure of the multispectral chip shown;

[0103] Figure 11 The light transmittance curve is a structure of a filter subunit having a regular square truncated pyramid shape and an inverted square truncated pyramid shape according to another embodiment of this application after modulation.

[0104] Figure 12 The light transmittance curve is a structure modulated according to another embodiment of this application, which has a base material layer and filter subunits with regular and inverted square pyramid shapes.

[0105] Figure 13 This is a schematic flowchart of a method for fabricating a spectral chip according to an embodiment of this application. Detailed Implementation

[0106] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0107] In the description of this application, for ease of description, spatial relative terms such as "below," "under," "below," "above," and "on" may be used to describe the relationship between one element and another. When an element or layer is referred to as "on," "adjacent to," or "connected to" other elements or layers, it may be directly on, adjacent to, or connected to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," or "directly connected to" other elements or layers, there are no intervening elements or layers.

[0108] It should also be understood that, for ease of description, the term "A and / or B" refers to all possible combinations of A and B, such as only A, only B, or A and B. The terms "at least one A or B" or "at least one of A and B" have a similar meaning to "A and / or B" and may include only A, only B, or A and B. The singular forms of the terms "a" or "this" may also include plural forms.

[0109] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0110] like Figure 1 As shown, the existing spectral chip 1 includes:

[0111] The silicon-based image sensor 10 is specifically a CMOS image sensor or a CCD image sensor;

[0112] The spectral modulation layer 12 includes multiple spectral modulation units 120 arranged in an array (shown by dashed boxes in the figure), wherein each spectral modulation unit 120 includes multiple sub-modulation units, which are nine in the example in the figure, and are respectively denoted as C1, C2, C3, C4, C5, C6, C7, C8 and C9.

[0113] In practical applications, the light source emits a spectrum towards the object to be imaged, so that the spectrum passes through the object and is then incident on the spectral chip 1. The intensity of the spectrum modulated by the incident light through the nine sub-modulation units arranged in the array is sensed and detected by the pixels 100 on the silicon-based image sensor 10, thereby determining each pixel point. Finally, all pixels are integrated to form an image.

[0114] Among them, the nine modulation channels are made of different spectral modulation materials, and the nine spectral modulation materials have the following properties: Figure 2 The transmittance curve shown is CN119437431A. Figure 4Similar curves are also shown. However, due to limitations inherent in the material itself, the transmittance curve of the modulation channel does not exhibit a more favorable linear response in certain critical wavelength ranges (also known as the critical band, such as 500-650 nm in cameras used for visible light imaging, for example). Figure 2 As shown, some modulation channels exhibit plateau regions or even notch lines in this band; CN119437431A Figure 4 (As shown, the same problem exists.) When performing color reproduction, such a structure is not sensitive to the key band and will be affected by interference from bands outside the key band, especially under low light conditions.

[0115] The conventional approach is to try to further adjust the material selection and ratio of each spectral modulation subunit. However, this method requires consideration of the material selection of each modulation subunit, which does not easily achieve satisfactory results. Even if it is achieved, when the application scenario changes (which means that the key band is different), it is necessary to try to select and match the materials of each modulation subunit for the new key band, which is too complicated.

[0116] Therefore, in a first aspect of this application, a spectral chip 2 is provided, such as Figure 3 As shown, it includes:

[0117] A silicon-based substrate on which an image sensing layer 20 is disposed;

[0118] The base material layer 21 is disposed on the image sensing layer;

[0119] A spectral modulation material layer 22 is disposed on the base material layer, wherein the spectral modulation material layer includes a plurality of filter units 220 arranged in an array, and each filter unit includes a plurality of filter sub-units with different transmittance curves.

[0120] In this process, the light incident on the spectral chip is modulated by both the spectral modulation material layer and the base material layer.

[0121] In one embodiment, the image sensing layer 20 may be a CMOS image sensor or a CCD image sensor formed on a silicon substrate, wherein the image sensing layer 20 includes a plurality of pixels 200.

[0122] For filter unit 220, in the figure, nine filter sub-units are still used as an example, denoted as C1, C2, C3, C4, C5, C6, C7, C8, and C9 respectively. In one specific example, as shown in the figure, the filter sub-units correspond one-to-one with the pixels 200 below, that is, their orthogonal projections on the silicon substrate are aligned with each other. However, this application is not limited to this. In another specific example, one filter sub-unit corresponds to multiple pixels 200 below. In this case, the multiple pixels 200 corresponding to one filter sub-unit together constitute a "superpixel". In this application, the terms "superpixel" and "pixel" are not distinguished.

[0123] Furthermore, in this application, the filter subunits C1-C9 are not limited to being fabricated using only spectral modulation materials. Some of the filter subunits can be fabricated using RGB filter materials, thus enabling the filter unit to include two types of filter arrays. The first type of filter array is used to acquire high-resolution low-spectral images; for example, the first type of filter array can be an RGB filter material array. The second type of filter array is used to acquire low-resolution high-spectral images; for example, the second type of filter array can be a filter array composed of spectral modulation materials. This type of filter array structure allows for the acquisition of high-resolution multispectral images in a single imaging process. It not only has a simple structure but also reduces the cost of improving the resolution of high-spectral images.

[0124] Unlike existing technologies, this application adds a base material layer 21. The incident light sequentially passes through the spectral modulation material layer 22 and the base layer 21, and is detected by the pixels in the image sensing layer 20 to form an image. Therefore, the incident light is modulated by each filter subunit and the base material layer.

[0125] The inventors introduced a base material layer 21 into the original structure and designed the shape of its transmittance curve (hereinafter referred to as the first transmittance curve). This makes the transmittance curve of the light incident on the spectral chip, after being modulated by the spectral modulation material layer and the base material layer, more sensitive in the preset wavelength range than in the range outside the preset wavelength range. Essentially, this makes the spectral chip have a higher transmittance for light in the key band (which, from a design perspective, can also be called the preset wavelength range) than for light outside that range.

[0126] In a preferred embodiment, the transmittance of the first transmittance curve within a preset wavelength range is higher than the transmittance outside the preset wavelength range.

[0127] Figure 4The figure shows the first transmittance curve designed for the visible light band 500-650nm. Specifically, the first transmittance curve satisfies the following constraints: peak transmittance wavelength is 500-640nm, T(400nm-490nm)≥70%, T(585nm-620nm)≥90%, and T(650nm-900nm)≥70%.

[0128] The process of modulating the transmittance curves of each filter unit using the first transmittance curve is mathematically equivalent to multiplying the transmittances of the two units at the same wavelength as a new transmittance, thus obtaining a wavelength-transmittance function. Alternatively, it can be described as using the transmittance on the first transmittance curve as a modulation factor to modulate the transmittance on the transmittance curves of each filter unit. This design of the first transmittance curve allows for the following: Figure 2 The transmittance curve shown is modulated within a preset wavelength range, for example, to improve or alleviate situations where the curve shows a plateau or even a dip within that wavelength range.

[0129] Specifically, if the waveform of the filter subunit within the preset wavelength range is plateau-shaped, the modulated transmittance curve within the preset wavelength range will exhibit a peak; if the waveform of the filter subunit within the preset wavelength range has a peak, the modulated transmittance curve within the preset wavelength range will still exhibit a peak, and the full width at half maximum (FWHM) of the modulated peak will be smaller than that of the peak before modulation; if the waveform of the filter subunit within the preset wavelength range is concave-shaped, the modulated transmittance curve within the preset wavelength range will exhibit a peak.

[0130] The following explanation uses C1-C9 in the diagram as an example. The transmittance curves of each filter sub-unit satisfy the following constraints:

[0131] TC1: Valley transmittance wavelength is 420-465nm, T(420nm-465nm)≤20%, T(515nm-900nm)≥80%;

[0132] TC2: Valley transmittance wavelength is 470-500nm, T(470nm-500nm)≤10%, T(525nm-900nm)≥90%;

[0133] TC3: Valley transmittance wavelength is 510-560nm, T(400nm-450nm)≥80%, T(510nm-560nm)≤20%; T(580nm-900nm)≥85%;

[0134] TC4: Valley transmittance wavelength is 585-615nm, T(415nm-480nm)≥80%, T(585nm-615nm)≤10%; T(650nm-900nm)≥75%;

[0135] TC5: Valley transmittance wavelength is 620-645nm, T(300nm-540nm) ≥80%, T(620nm-645nm) ≤10%; T(675nm-900nm) ≥85%;

[0136] TC6: Valley transmittance wavelength is 625-660nm, T(400nm-535nm) ≥80%, T(625nm-660nm) ≤10%; T(690nm-900nm) ≥85%;

[0137] TC7: Valley transmittance wavelength is 655-700nm; T(400nm-545nm) ≥80%; T(655nm-700nm) ≤20%; T(740nm-900nm) ≥85%;

[0138] TC8: Valley transmittance wavelength is 685-730nm, T(400nm-565nm) ≥80%, T(685nm-730nm) ≤10%; T(780nm-900nm) ≥85%;

[0139] TC9: Valley transmittance wavelength is 700-745nm, T(470nm-590nm) ≥80%, T(700nm-745nm) ≤40%; T(790nm-900nm) ≥80%.

[0140] Sutra Figure 4 Modulation of the first transmittance curve shown yields the following result: Figure 5 The line shape shown:

[0141] The transmittance curves of light incident on the spectral chip, after being modulated by the spectral modulation material layer and the base material layer, satisfy the following constraints:

[0142] TA1: Peak transmittance wavelength is 500nm-650nm, T(430nm-460nm)≤10%, T(500nm-650nm)≥60%, T(650nm-900nm)≥55%;

[0143] TA2: Peak transmittance wavelength is 550-620nm, T(460nm-500nm)≤10%, T(550nm-620nm)≥80%, T(650nm-900nm)≥65%;

[0144] TA3: Peak transmittance wavelength is 575-635nm, T(510nm-550nm)≤15%, T(575nm-635nm)≥70%, T(650nm-900nm)≥60%;

[0145] TA4: Valley transmittance wavelength is 550-620nm, T(400nm-540nm)≥20%, T(550nm-620nm)≤20%, T(640nm-900nm)≥55%;

[0146] TA5: Valley transmittance wavelength is 615-650nm, T(300nm-565nm) ≥60%, T(615nm-650nm) ≤20%, T(675nm-900nm) ≥60%;

[0147] TA6: Valley transmittance wavelength is 600-670nm, T(400nm-560nm) ≥60%, T(600nm-670nm) ≤20%, T(700nm-900nm) ≥60%;

[0148] TA7: Valley transmittance wavelength is 630-700nm, T(400nm-575nm) ≥60%, T(630nm-700nm) ≤20%, T(735nm-900nm) ≥60%;

[0149] TA8: Valley transmittance wavelength is 635-735nm, T(400nm-590nm) ≥60%, T(635nm-735nm) ≤20%, T(780nm-900nm) ≥60%;

[0150] TA9: Peak transmittance wavelength is 500-625nm, T(300nm-480nm)≤60%, T(500nm-625nm)≥60%, T(685nm-750nm)≤40%, T(810nm-900nm)≥60%.

[0151] In this application, by introducing a base material layer with a transmittance curve designed for a preset wavelength range, the transmittance curve of the original light modulation subunit is modulated. This optimizes the response of the spectral camera to the preset wavelength range, improves image quality, reduces interference from other bands (the presence of the base material layer reduces the transmittance of light outside the preset wavelength range), and ensures accurate color reproduction during shooting. Even if the application scenario changes (the key wavelength changes), only the transmittance curve of a single base layer needs to be designed for the new target wavelength, rather than adjusting the transmittance curves of multiple filter subunits in a coordinated manner.

[0152] The following explains how to achieve the transmittance curve designed for the base material layer. The inventor's idea is to make it compatible with the materials and processes of the filter subunit.

[0153] In this application, the material of the filter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment and solvent material.

[0154] The resin materials include soluble resins, such as phenolic resins, polyurethane resins, polyvinyl alcohol resins, and maleic anhydride resins; and photocurable resins, such as polyimide resins, polyvinyl alcohol resins, epoxy resins, and styrene resins.

[0155] Photoinitiator materials include benzophenones, alkyl phenyl ketones, benzoin and its derivatives, iodonium salts, and iron aromatics.

[0156] Pigments include aniline pigments, phthalocyanine pigments, azo pigments, and pyrrole pigments.

[0157] Solvent-based materials include ethylene glycol methyl ethers, propylene glycol methyl ether acetates, triethylene glycol methyl ethers, and ethyl 3-ethoxypropionate.

[0158] By selecting and proportioning these materials, the transmittance curves of each of the aforementioned filter sub-units can be obtained.

[0159] Based on this, the base material layer is selected to be a colloidal curable film made of resin material, photoinitiator material and solvent material.

[0160] exist Figure 3 In the example shown, the base material layer 21 is a monolithic structure, meaning that the base material layer 21 is formed on the image sensing layer 20 in the form of a monolithic deposition, covering the image sensing layer 20. However, in this case, when light exits from a certain filter subunit and enters the base material layer, there will be scattering to areas outside the base material layer region corresponding to that filter subunit, thus forming crosstalk. This situation is particularly prominent when the base material layer is thick.

[0161] Therefore, this application provides another preferred structure. Specifically, the base material layer includes:

[0162] A mesh structure formed of a dielectric material, wherein the orthographic projection of each mesh of the mesh structure onto the image sensing layer is aligned with the orthographic projection of one or more filter subunits onto the image sensing layer;

[0163] The base material is filled into the mesh, wherein the base material is the same in each mesh.

[0164] The medium material is preferably a light-absorbing material, such as the black matrix commonly used in the display panel industry.

[0165] As those skilled in the art can anticipate, the addition of a base material layer reduces the energy utilization of light, a situation that is further highlighted in embodiments with a grid structure formed by light-absorbing materials.

[0166] Typically, the solution that comes to mind is to reduce the thickness of the base material layer. However, if the base layer is too thin, it will be impossible to effectively modulate the key bands.

[0167] Therefore, in one embodiment, experiments revealed that the thickness of the base layer ranges from 50 to 500 nm, and the thickness of the modulation layer ranges from 500 to 1000 nm. Within this range, the spectral modulation channels of the base layer and modulation layer are advantageous for fabrication and can achieve better spectral modulation performance. A base layer thickness exceeding 500 nm increases the optical path length of the modulation channel, leading to spectral crosstalk between adjacent pixels in the image sensing layer. For the modulation layer, if its thickness is less than 500 nm, it loses its broadband modulation capability and cannot achieve the ideal modulation spectral line shape; while if the modulation layer thickness exceeds 1000 nm, it makes the fabrication process difficult and, in addition to increasing spectral crosstalk, also reduces the transmittance of the modulation spectral lines.

[0168] However, this overall adjustment method does not take into account the differences in materials of different filter sub-units (e.g., different wavelengths of light scatter the same material to different degrees). A more preferred embodiment is given below.

[0169] In embodiments where the base material layer 21 is a single layer structure, within the entire spectral chip, the thickness of the base material layer corresponding to different filter sub-units in the same filter unit exhibits a stepped appearance. For example, such as... Figure 6 As shown, where Figure 6 (a) is a top view of the spectral chip, and (b) is a cross-sectional view along the dashed line in the figure. Figure 6 As shown in (b), the thickness of the base material region corresponding to C1 is greater than that corresponding to C2, C3, C4, C5, C6, C7, C8, and C9. The overall base material layer is stepped.

[0170] As will be discussed in the process section later, the thickness varies depending on which filter sub-unit is fabricated first; the thickness of the corresponding base material region fabricated first is greater than that of the corresponding base material region fabricated later. Of course, the overall thickness of the base layer can still be controlled within the range of 50-500nm.

[0171] In the specific process, filter sub-units corresponding to wavelength ranges insensitive to scattering by the base layer material can be selected as C1 (made first), and filter sub-units corresponding to wavelength ranges sensitive to scattering by the base layer material can be selected as C9 (made later). This takes into account the crosstalk problem. At the same time, for the subsequent device flatness, the sum of the thickness of each filter sub-unit and the thickness of its corresponding base material layer region in the projection relationship is equal. Of course, the thickness of the modulation layer can still be controlled within 500-1000nm. In this way, with the total thickness being the same, the thickness ratio of each filter sub-unit to the corresponding base layer material can be varied, which is equivalent to the material ratio in the vertical direction being varied in each channel. This increases the means to adjust the transmittance curve shape, thereby enabling a more refined obtaining of the desired curve shape.

[0172] In the above-described mesh structure implementation, the above concept can also be realized. In the entire spectral chip, the sum of the thickness of the base material in all meshes and the thickness of the corresponding filter sub-units are equal; and in the same filter unit, the thickness of the base material corresponding to different filter sub-units is stepped.

[0173] On the other hand, regardless of the transmittance curve of existing spectral chips ( Figure 2 ) or the transmittance curve of the spectral chip after adding the aforementioned basic material layer of this application ( Figure 5 All of these exhibit aliasing in at least some channels within certain wavelength ranges. This aliasing becomes more severe as the number of channels increases.

[0174] Figure 7 and Figure 8 In respectively Figure 2 and Figure 5 Based on this, the corresponding aliasing region is shown (this phenomenon exists even in the aforementioned preset wavelength region after the addition of the base material layer), which leads to low spectral resolution, making it difficult to accurately identify and modulate the spectral signal, thus limiting the application of the spectral chip in complex environments.

[0175] Typically, when fabricating each filter subunit, the desired ideal morphology is vertical or nearly vertical. Researchers have explored various methods for fabricating vertical or near-vertical filter subunits. However, the inventors of this application have discovered through experimentation that when the edges of the filter subunits are inclined, meaning that adjacent filter subunits have an overlap area (inclined interface), Figure 7 or Figure 8 The waveform in the aliasing region shown will demix, which gives the inventors a new idea to further optimize the transmittance curve.

[0176] Therefore, in one embodiment of this application, there is at least one inclined overlap region relative to the silicon substrate between each filter subunit and its adjacent filter subunit, the inclined overlap region being projected onto the silicon substrate to bridge two adjacent pixels on the image sensing layer.

[0177] In a preferred embodiment, such as Figure 9 As shown, Figure 9 (a) is a top view of the spectral chip, and (b) is a cross-sectional view along the dashed line in the figure. From Figure 9 As can be seen in (b), C2, C4, C6 and C8 are regular trapezoids (corresponding to a regular square frustum in the concept of solids), and C1, C3, C5, C7 and C9 are inverted trapezoids (corresponding to an inverted square frustum in the concept of solids).

[0178] Please note that "regular" and "inverted" are relative concepts. In this application, a regular truncated square refers to a face on the upper and lower surfaces that is closer to the image sensing layer with a larger area than the face away from the image sensing layer. That is, relative to the image sensing layer, the filter subunit is smaller at the top and larger at the bottom. An inverted truncated square refers to a face on the upper and lower surfaces that is closer to the image sensing layer with a smaller area than the face away from the image sensing layer. That is, relative to the image sensing layer, the filter subunit is larger at the top and smaller at the bottom.

[0179] Such a structure can achieve such a modulation effect, such as Figure 10 As shown, taking C1-C3 as an example, the light entering pixel P1 is modulated by C1 and C2 (the R1 area to the left of the dashed line L1) (and also by the underlying base material layer below, the same below); the light entering pixel P3 is modulated by C3 and C2 (the R2 area to the right of the dashed line L2); the light entering pixel P2 is modulated by C1 (the R3 area to the right of the dashed line L3), C2, and C3 (the R4 area to the left of the dashed line L4).

[0180] The above examples use regular and inverted square truncated pyramids as illustrations; however, this application is not limited to these. Any truncated pyramid structure is acceptable. That is, a common modulation effect can be achieved when a filter subunit and its adjacent filter subunits have at least one beveled overlap area. For example, C1 and C2, C4 each have beveled overlap areas. Those skilled in the art, guided by the teachings of this application, can adjust the area and slope of the overlap area to ensure that the light entering each pixel is modulated by at least two different modulation subunits, thereby finely adjusting the linearity of the light transmittance curve entering the pixel and alleviating aliasing at certain wavelengths.

[0181] Furthermore, although the frustum-structured filter subunit in the above example coexists with the base material layer, this application is not limited thereto; the frustum-structured filter subunit can be used independently (i.e., in...). Figure 1 The structure shown uses frustum-shaped filter units to achieve its effect. Specifically, the transmittance curves of each channel can be more precisely adjusted by changing the area and slope of the overlap region, thereby alleviating aliasing of the transmittance curves at certain wavelengths.

[0182] In a preferred example, the angle between the beveled overlap area and the surface of the spectral modulation material layer is between 60 and 90 degrees.

[0183] Figure 11 The figure shows the transmittance curve of light incident on the multispectral chip after being modulated by the spectral modulation material layer in the case of a spectral chip structure without a base material layer, which satisfies the following constraint:

[0184] TC1: Valley transmittance wavelength is 400-550nm; T(430nm-495nm)≤10%; T(550nm-900nm)≥70%;

[0185] TC2: Valley transmittance wavelength is 400-575nm; T (420nm-550nm) ≤15%; T (585nm-900nm) ≥65%;

[0186] TC3: Valley transmittance wavelength is 400-580nm; T(455nm-550nm)≤15%; T(600nm-900nm)≥75%;

[0187] TC4: Valley transmittance wavelength is 500-680nm; T(400nm-500nm) ≥ 65%; T(580nm-645nm) ≤ 10%; T(700nm-900nm) ≥ 65%;

[0188] TC5: Valley transmittance wavelength is 500-675nm; T(400nm-500nm) ≥50%; T(550nm-650nm) ≤10%; T(700nm-900nm) ≥60%;

[0189] TC6: Valley transmittance wavelength is 550-700nm; T(400nm-535nm)≥65%; T(600nm-665nm)≤10%; T(700nm-900nm)≥75%;

[0190] TC7: Valley transmittance wavelength is 550-750nm; T(400nm-550nm) ≥65%; T(630nm-725nm) ≤10%; T(800nm-900nm) ≥75%;

[0191] TC8: Valley transmittance wavelength is 550-750nm; T(460nm-545nm)≥55%; T(625nm-740nm)≤10%; T(775nm-900nm)≥55%;

[0192] TC9: Valley transmittance wavelength is 600-700nm; T(465nm-540nm)≥70%; T(680nm-745nm)≤10%; T(785nm-900nm)≥70%.

[0193] Compare Figure 11 and Figure 7 It is evident that the combination of regular and inverted square truncated pyramid shapes helps to separate partially overlapping transmittance curves, thereby improving the distinction between different spectra and enhancing the effect of spectral modulation.

[0194] Figure 12 The figure shows the transmittance curve of light incident on the multispectral chip after being modulated by the spectral modulation material layer and the base material layer in the case of a spectral chip structure with a base material layer, which satisfies the following constraints:

[0195] TA1: Peak transmittance wavelength is 520-640nm; T(420nm-495nm)≤10%; T(580nm-625nm)≥55%; T(670nm-900nm)≥50%;

[0196] TA2: Peak transmittance wavelength is 570-645nm; T(425nm-550nm) ≤10%; T(600nm-630nm) ≥70%; T(670nm-900nm) ≥55%;

[0197] TA3: Peak transmittance wavelength is 575-645nm; T(460nm-555nm)≤15%; T(580nm-620nm)≥70%; T(660nm-900nm)≥55%;

[0198] TA4: Valley transmittance wavelength is 550-650nm; T (400nm-500nm) ≥ 45%; T (580nm-645nm) ≤ 10%; T (700nm-900nm) ≥ 50%;

[0199] TA5: Valley transmittance wavelength is 550-675nm; T(425nm-500nm) ≥35%; T(550nm-665nm) ≤10%; T(700nm-900nm) ≥45%;

[0200] TA6: Valley transmittance wavelength is 500-650nm; T(350nm-450nm)≤40%; T(485nm-615nm)≥50%; T(800nm-900nm)≥60%;

[0201] TA7: Valley transmittance wavelength is 575-750nm; T(400nm-570nm) ≥45%; T(630nm-730nm) ≤10%; T(775nm-900nm) ≥50%;

[0202] TA8: Valley transmittance wavelength is 600-750nm; T(460nm-565nm)≥40%; T(620nm-745nm)≤10%; T(800nm-900nm)≥45%;

[0203] TA9: Valley transmittance wavelength is 600-760nm; T(460nm-580nm)≥50%; T(635nm-645nm)≤15%; T(800nm-900nm)≥50%.

[0204] Compare Figure 12 and Figure 8 It is evident that the combination of regular and inverted square truncated pyramid shapes not only helps to separate transmittance curves that are partially overlapped outside the preset wavelength range, but also helps to separate transmittance curves that are partially overlapped within the preset wavelength range, thereby improving the distinguishability between different spectra and enhancing the effect of spectral modulation.

[0205] Furthermore, by combining regular and inverted truncated square shapes, the transmittance of the spectral chip within the preset wavelength range is also relatively improved.

[0206] In summary, this structure not only optimizes spectral discrimination but also improves the accuracy of spectral modulation, enabling the spectral chip to perform effective modulation and identification over a wider wavelength range. Through this structural optimization, the overall performance of the spectral chip is enhanced, allowing it to better handle complex spectral signal modulation requirements.

[0207] As mentioned earlier, it is often difficult to form a perfect cube or cuboid structure in the ideal filter unit film layer in the process. There will always be a slight slope. The inventors of this application have taken advantage of this defect and amplified it by deliberately making it into the shape of a regular square truncated pyramid and an inverted square truncated pyramid to form an overlapping area. This is easier to achieve in the process preparation, thereby further improving the preparation accuracy and quality.

[0208] Furthermore, the above examples use 500-650nm as the key wavelength band; however, this application is not limited to this. For example, if considering applications in the ultraviolet spectral imaging field, such as surface defect detection, fluorescence imaging, forensic medicine and security (e.g., bloodstain and fingerprint recognition), and cultural relic identification and restoration, the key wavelength band is between 200-400nm. If considering applications in the infrared spectral imaging field, such as agriculture, food inspection, medical imaging, security monitoring, and material sorting, the key wavelength band is between 800-1700nm. Based on the teachings of this application, the transmittance curves of the corresponding basic material layers can be designed for the corresponding wavelength bands.

[0209] A second aspect of this application provides a spectroscopic camera, including the spectroscopic chip described in the first aspect. Of course, the spectroscopic camera may also include a microlens array formed on a spectral modulation layer, etc.

[0210] A third aspect of this application provides a method for fabricating a spectral chip, such as... Figure 13 As shown, it includes:

[0211] S10. An image sensing layer is formed on a silicon substrate;

[0212] S20. A base material layer is formed on the image sensing layer;

[0213] S30. A spectral modulation material layer is formed on the base material layer, wherein the spectral modulation material layer includes multiple filter units arranged in an array, and each filter unit includes multiple filter sub-units with different transmittance curves.

[0214] In this process, the light incident on the spectral chip is modulated by both the spectral modulation material layer and the base material layer.

[0215] In one embodiment, steps 20 and S30 include:

[0216] A base material is formed on the image sensing layer;

[0217] The first filter sub-unit material of each filter unit is formed on the base material;

[0218] The first filter subunit material is patterned, wherein the patterned first filter subunit is cuboid, and during this process, the base material except for the base material at the position of the first filter subunit to be formed is cleaned and thinned to a first preset thickness.

[0219] The i+1th filter unit material in each filter unit is formed on the patterned i-th filter unit material and the thinned base material;

[0220] The material of the (i+1)th filter subunit is patterned, wherein the patterned (i+1)th filter subunit is a cuboid, and during this process, the base material other than the base material at the position of the (i+1)th filter subunit to be formed and the base material at the positions of the first to the i-th filter subunits that have been formed is cleaned and thinned to the (i+1)th preset thickness, wherein the (i+1)th filter subunit is adjacent to the i-th filter subunit, i traverses from 1 to n, and n is the total number of filter subunits included in each filter unit.

[0221] by Figure 6 Taking a 9-channel structure as an example (forming a cube shape), the specific steps include:

[0222] Base material layer preparation: A base material layer is formed on the image sensing layer;

[0223] Fabrication of filter subunit C1: C1 material is formed on the base material, and the C1 material is patterned according to the designed shape and specific specifications of the filter subunit C1 (exposure and development). The C1 material outside the filter subunit C1 is removed. During the patterning process, the base material except for the base material at the position of the first filter subunit to be formed is cleaned and thinned to a certain thickness.

[0224] Fabrication of filter subunit C2: C2 material is formed on patterned C1 material and thinned base material; C2 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C2; C2 material outside of filter subunit C2 is removed; during the patterning process, the base material except for the base material at the position to be formed C2 and the base material at the position of the already formed C1 is cleaned and thinned to a certain thickness.

[0225] The thickness of the reproduced filter subunit C2 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunit C1 and filter subunit C2 are on the same plane to ensure that the morphology of filter subunit C1 is undamaged.

[0226] Fabrication of filter subunit C3: C3 material is formed on patterned C1 material, C2 material and thinned base material; C3 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C3; C3 material outside of filter subunit C3 is removed; during the patterning process, the base material except for the base material at the position to be formed C3 and the base material at the positions of C1-C2 that have been formed is cleaned and thinned to a certain thickness.

[0227] The thickness of the reproduced filter subunit C3 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 and C3 are on the same plane to ensure that the morphology of filter subunits C1 and C3 is undamaged.

[0228] Fabrication of filter subunit C4: C4 material is formed on patterned C1-C3 materials and thinned base material; C4 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C4; C4 material outside filter subunit C4 is removed; during the patterning process, the base material except for the base material at the position to be formed C4 and the base material at the positions of C1-C3 is cleaned and thinned to a certain thickness.

[0229] The thickness of the reproduced filter subunit C4 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C4 are on the same plane to ensure that the morphology of filter subunits C1 to C4 is undamaged.

[0230] Fabrication of filter subunit C5: C5 material is formed on patterned C1-C4 materials and thinned base material; C5 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C5; C5 material outside of filter subunit C5 is removed; during the patterning process, the base material except for the base material at the position to be formed C5 and the base material at the positions of C1-C4 is cleaned and thinned to a certain thickness.

[0231] The thickness of the reproduced filter subunit C5 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C5 are on the same plane to ensure that the morphology of filter subunits C1 to C5 is undamaged.

[0232] Fabrication of filter subunit C6: C6 material is formed on patterned C1-C5 materials and thinned base material; C6 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C6; C6 material outside of filter subunit C6 is removed; during the patterning process, the base material except for the base material at the position to be formed C6 and the base material at the positions of C1-C5 is cleaned and thinned to a certain thickness.

[0233] The thickness of the reproduced filter subunit C6 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C6 are on the same plane to ensure that the morphology of filter subunits C1 to C6 is undamaged.

[0234] Fabrication of filter subunit C7: C7 material is formed on patterned C1-C6 materials and thinned base material; C7 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C7; C7 material outside of filter subunit C7 is removed; during the patterning process, the base material except for the base material at the position to be formed C7 and the base material at the positions of C1-C6 is cleaned and thinned to a certain thickness.

[0235] The thickness of the reproduced filter subunit C7 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C6 are on the same plane to ensure that the morphology of filter subunits C1 to C7 is undamaged.

[0236] Fabrication of filter subunit C7: C7 material is formed on patterned C1-C6 materials and thinned base material; C7 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C7; C7 material outside of filter subunit C7 is removed; during the patterning process, the base material except for the base material at the position to be formed C7 and the base material at the positions of C1-C6 is cleaned and thinned to a certain thickness.

[0237] The thickness of the reproduced filter subunit C7 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C6 are on the same plane to ensure that the morphology of filter subunits C1 to C7 is undamaged.

[0238] Fabrication of filter subunit C8: C8 material is formed on patterned C1-C7 materials and thinned base material; C8 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C8; C8 material outside of filter subunit C8 is removed; during the patterning process, the base material except for the base material at the position to be formed C8 and the base material at the positions of C1-C7 is cleaned and thinned to a certain thickness.

[0239] The thickness of the reproduced filter subunit C8 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C7 are on the same plane to ensure that the morphology of filter subunits C1 to C8 is undamaged.

[0240] Fabrication of filter subunit C9: C9 material is formed on patterned C1-C8 materials and thinned base material; C9 material is patterned (exposed and developed) according to the designed shape and specific specifications of filter subunit C9; C9 material outside of filter subunit C9 is removed; during the patterning process, the base material except for the base material at the position to be formed C9 and the base material at the positions of C1-C8 is cleaned and thinned to a certain thickness.

[0241] The thickness of the reproduced filter subunit C9 and the thickness of the remaining base layer can also be tested using a three-dimensional confocal microscope to ensure that they meet the usage requirements. At the same time, it can be tested whether the surfaces of filter subunits C1 to C8 are on the same plane to ensure that the morphology of filter subunits C1 to C9 is undamaged.

[0242] Through these process steps, the sum of the thickness of each filter subunit and its corresponding base material in the entire spectral chip is equal; and within the same filter unit, the thickness of the base material corresponding to different filter subunits is stepped, with the base material corresponding to the filter subunits fabricated earlier having a larger thickness.

[0243] Optionally, before forming a base material layer on the image sensing layer, the method further includes:

[0244] A dielectric material is formed on the image sensing layer;

[0245] The medium material is patterned to form a grid structure, wherein the orthographic projection of each mesh of the grid structure onto the image sensing layer is aligned with the orthographic projection of one or more filter sub-units to be formed onto the image sensing layer.

[0246] Then, through the above process steps, in the entire spectral chip, the sum of the thickness of the base material in all the meshes and the thickness of the corresponding filter sub-units is equal; and in the same filter unit, the thickness of the base material corresponding to different filter sub-units is stepped, with the thickness of the base material corresponding to the filter sub-units fabricated first being larger.

[0247] Alternatively, in an alternative embodiment, steps S20 and S30 include:

[0248] A base material is formed on the image sensing layer;

[0249] The base material is heated and cured to the desired hardness;

[0250] The first filter sub-unit material of each filter unit is formed on the base material;

[0251] The material of the first filter subunit is patterned, wherein the patterned first filter subunit is in the shape of a regular square frustum;

[0252] The j-th filter unit material in each filter unit is formed on the patterned i-th filter unit material and the exposed base material;

[0253] The material of the j-th filter subunit is patterned, wherein the patterned j-th filter subunit is a regular square frustum, wherein i and j traverse from 1 to n and the i-th filter subunit and the j-th filter subunit are not adjacent in physical space, and n is the total number of filter subunits included in each filter unit.

[0254] The areas of the base material exposed outside the areas forming all the filter sub-units in the shape of a regular square frustum are filled with the remaining filter sub-unit materials to form each filter sub-unit. In the same filter sub-unit, two adjacent filter sub-units are a combination of a regular square frustum and an inverted square frustum, and the two form a sloping overlapping area.

[0255] by Figure 7 Taking a 9-channel structure as an example (using the combination of a regular square truncated pyramid and an inverted square truncated pyramid as an example), the specific steps include:

[0256] A base material is formed on the image sensing layer;

[0257] The base material is heated and cured to the desired hardness. Appropriate parameters for the exposure time of the base material layer are set to ensure that the thickness of the base layer remains essentially constant during the cleaning process.

[0258] First, fabricate frustum-shaped filter sub-units, for example, C2, C4, C6, and C8 sequentially, i.e., fabricating the filter sub-units in their arrangement order. Then, fill in the corresponding positions with C1, C3, C5, C7, and C9. The specific process implementation is the same as described above. Figure 6 The structure is similar, so I will not repeat it here.

[0259] Those skilled in the art will understand that although the above example shows the preparation of the regular square frustum in the order of C2, C4, C6, C8, this application is not limited to this. C6 or C8 can be prepared after C2, as long as the filter sub-units prepared one after the other are not adjacent in physical space.

[0260] The above description has been given for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, additions, and sub-combinations therein.

[0261] It should be noted that although the steps in the above embodiments are described in a specific order, those skilled in the art will understand that in order to achieve the effect of this application, different steps do not necessarily have to be executed in such an order. They can be executed simultaneously (in parallel) or in other orders, and these variations are all within the scope of protection of this application.

[0262] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A spectral chip, characterized in that, include: A silicon-based substrate with an image sensing layer disposed thereon; A base material layer is disposed on the image sensing layer; A spectral modulation material layer is disposed on the base material layer, wherein the spectral modulation material layer comprises multiple filter units arranged in an array, and each filter unit comprises multiple filter sub-units with different transmittance curves. In this process, the light incident on the spectral chip is modulated by both the spectral modulation material layer and the base material layer.

2. The spectral chip according to claim 1, characterized in that, The base material layer has a first transmittance curve, wherein the shape of the first transmittance curve is designed such that the transmittance curve of the light incident on the spectral chip after being modulated by the spectral modulation material layer and the base material layer is more sensitive in a preset wavelength range than in a response outside the preset wavelength range.

3. The spectral chip according to claim 2, characterized in that, The first transmittance curve has a higher transmittance within a preset wavelength range than the transmittance outside the preset wavelength range.

4. The spectral chip according to claim 3, characterized in that, If the waveform of the filter subunit is plateau-shaped within the preset wavelength range, the waveform of the modulated transmittance curve within the preset wavelength range will show a peak. or If the waveform of the filter subunit has a peak in the preset wavelength range, and the waveform of the modulated transmittance curve in the preset wavelength range still has a peak, the half-width of the modulated peak is smaller than that of the peak before modulation. or If the waveform of the filter subunit is concave within the preset wavelength range, the waveform of the modulated transmittance curve within the preset wavelength range will show a peak.

5. The spectral chip according to any one of claims 2-4, characterized in that, The base material layer is a colloidal cured film composed of resin materials, photoinitiator materials, and solvent materials; and / or The filter subunit is a colloidal cured film composed of resin material, photoinitiator material, pigment, and solvent material.

6. The spectral chip according to claim 5, characterized in that, The base material layer is a single-layer structure.

7. The spectral chip according to claim 6, characterized in that, Throughout the entire spectral chip, the sum of the thicknesses of each filter subunit and its corresponding base material layer in projection relation is equal; and Within the same filter unit, the thickness of the base material layer corresponding to different filter sub-units is stepped.

8. The spectral chip according to claim 5, characterized in that, The base material layer includes: A mesh structure formed of a dielectric material, wherein the orthographic projection of each mesh of the mesh structure onto the image sensing layer is aligned with the orthographic projection of one or more filter subunits onto the image sensing layer; The base material is filled into the mesh, wherein the base material is the same in each mesh.

9. The spectral chip according to claim 8, characterized in that, The base material in each mesh of the mesh structure corresponds to a filter sub-unit, wherein, Throughout the entire spectral chip, the sum of the thickness of the base material in all meshes and the thickness of their corresponding filter sub-units is equal; and Within the same filter unit, the thickness of the base material corresponding to different filter sub-units is stepped.

10. The spectral chip according to any one of claims 6-9, characterized in that, The thickness of the filter subunit ranges from 500 to 1000 nm, and the thickness of the base material layer ranges from 50 to 500 nm.

11. The spectral chip according to claim 4, characterized in that, The preset wavelength range is 500-650nm; The first transmittance curve satisfies the following constraints: peak transmittance wavelength is 500-640nm, T(400nm-490nm)≥70%, T(585nm-620nm)≥90%, T(650nm-900nm)≥70%; The filter unit comprises 3*3 filter sub-units C1-C9, and the transmittance curves of the filter sub-units satisfy the following constraints: TC1: Valley transmittance wavelength is 420-465nm, T(420nm-465nm)≤20%, T(515nm-900nm)≥80%; TC2: Valley transmittance wavelength is 470-500nm, T(470nm-500nm)≤10%, T(525nm-900nm)≥90%; TC3: Valley transmittance wavelength is 510-560nm, T(400nm-450nm)≥80%, T(510nm-560nm)≤20%; T(580nm-900nm)≥85%; TC4: Valley transmittance wavelength is 585-615nm, T(415nm-480nm)≥80%, T(585nm-615nm)≤10%; T(650nm-900nm)≥75%; TC5: Valley transmittance wavelength is 620-645nm, T(300nm-540nm) ≥80%, T(620nm-645nm) ≤10%; T(675nm-900nm) ≥85%; TC6: Valley transmittance wavelength is 625-660nm, T(400nm-535nm) ≥80%, T(625nm-660nm) ≤10%; T(690nm-900nm) ≥85%; TC7: Valley transmittance wavelength is 655-700nm; T(400nm-545nm) ≥80%; T(655nm-700nm) ≤20%; T(740nm-900nm) ≥85%; TC8: Valley transmittance wavelength is 685-730nm, T(400nm-565nm) ≥80%, T(685nm-730nm) ≤10%; T(780nm-900nm) ≥85%; TC9: Valley transmittance wavelength is 700-745nm, T(470nm-590nm) ≥80%, T(700nm-745nm) ≤40%; T(790nm-900nm) ≥80%; The transmittance curves of the light incident on the spectral chip, after being modulated by the spectral modulation material layer and the base material layer, respectively satisfy the following constraints: TA1: Peak transmittance wavelength is 500nm-650nm, T(430nm-460nm)≤10%, T(500nm-650nm)≥60%, T(650nm-900nm)≥55%; TA2: Peak transmittance wavelength is 550-620nm, T(460nm-500nm)≤10%, T(550nm-620nm)≥80%, T(650nm-900nm)≥65%; TA3: Peak transmittance wavelength is 575-635nm, T(510nm-550nm)≤15%, T(575nm-635nm)≥70%, T(650nm-900nm)≥60%; TA4: Valley transmittance wavelength is 550-620nm, T(400nm-540nm)≥20%, T(550nm-620nm)≤20%, T(640nm-900nm)≥55%; TA5: Valley transmittance wavelength is 615-650nm, T(300nm-565nm) ≥60%, T(615nm-650nm) ≤20%, T(675nm-900nm) ≥60%; TA6: Valley transmittance wavelength is 600-670nm, T(400nm-560nm) ≥60%, T(600nm-670nm) ≤20%, T(700nm-900nm) ≥60%; TA7: Valley transmittance wavelength is 630-700nm, T(400nm-575nm) ≥60%, T(630nm-700nm) ≤20%, T(735nm-900nm) ≥60%; TA8: Valley transmittance wavelength is 635-735nm, T(400nm-590nm) ≥60%, T(635nm-735nm) ≤20%, T(780nm-900nm) ≥60%; TA9: Peak transmittance wavelength is 500-625nm, T(300nm-480nm)≤60%, T(500nm-625nm)≥60%, T(685nm-750nm)≤40%, T(810nm-900nm)≥60%.

12. A spectroscopic camera, characterized in that, The spectral chip included in any one of claims 1-11.

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