Multispectral filter

Abstract

The utility model provides a multispectral filter. The multispectral filter comprises a substrate; the first refraction layer is distributed on the surface of the substrate; the first refraction layer comprises a plurality of first step parts, and at least two first step parts are different in height in the direction perpendicular to the substrate; the induced transmission layer is distributed on the surface of the first refraction layer away from the substrate; the induced transmission layer comprises a plurality of second step parts, a metal layer and a plurality of third step parts; the second refraction layer is distributed on the surface, away from the first refraction layer, of the induction transmission layer; the second refraction layer comprises a plurality of fourth step parts, and at least two fourth step parts are different in height in the direction perpendicular to the substrate; the first step part, the second step part, the metal layer, the third step part and the fourth step part are stacked to form a filtering channel; and the filtering channels with different heights are used for transmitting light with different target wavelengths. The problem that high spectral resolution and high light transmittance in a filter cannot be considered at the same time is solved, and the filter has good cut-off region inhibition and permeability.

Description

Multispectral filter Technical Field

[0001] This application relates to the field of filter technology, and in particular to multispectral filters. Background Technology

[0002] A spectrum represents the distribution of optical intensity with optical wavelength or optical frequency. Filters are an effective technique for obtaining spectral distribution.

[0003] In existing technologies, conventional metal Fabry-Perot filters are typically used to form the spectrum. These filters have low transmittance, a wide half-width at half-maximum (HWHM), and low spectral resolution. Another type of filter uses a stack of metal and dielectric layers to process incident light. This type of filter has a smaller HWHM and generates a higher spectral resolution, but it has a narrower cutoff suppression. It requires the addition of long- and short-wavelength filters to achieve effective cutoff suppression, but adding filters exponentially increases the manufacturing complexity and cost of the filter.

[0004] Therefore, it is now necessary to solve the problem of the inability to simultaneously achieve both spectral resolution and transmittance in filters, as well as the issues of high manufacturing difficulty and high production costs. Summary of the Invention

[0005] In view of this, the purpose of this application is to propose a multispectral filter that solves the problem of the inability to simultaneously achieve high spectral resolution and high transmittance in a filter. It has good cutoff region suppression and transmittance, and simplifies the manufacturing process and reduces production costs.

[0006] To achieve one of the above objectives, this application provides a multispectral filter, comprising:

[0007] Base;

[0008] A first refractive layer is distributed on the surface of the substrate, and the first refractive layer is used to interfere with light of a certain wavelength.

[0009] The first refractive layer includes a plurality of first stepped portions, at least two of which have different heights in a direction perpendicular to the substrate;

[0010] An induced transmission layer is distributed on the surface of the first refractive layer away from the substrate;

[0011] The induced transmission layer includes a plurality of second step portions, a metal, and a plurality of third step portions, wherein at least two of the second step portions have different heights in a direction perpendicular to the substrate, and at least two of the third step portions have different heights in a direction perpendicular to the substrate.

[0012] The second refractive layer is distributed on the surface of the induced transmission layer away from the first refractive layer, and the second refractive layer is used to interfere with light of a certain wavelength.

[0013] The second refractive layer includes a plurality of fourth steps, at least two of the fourth steps having different heights in a direction perpendicular to the substrate;

[0014] A first stepped portion, a second stepped portion, a metal layer, a third stepped portion, and a fourth stepped portion are stacked in a direction perpendicular to the substrate to form a filter channel;

[0015] The filter channels at different heights are used to tune light to different target wavelengths.

[0016] As a further improvement to the embodiments of this application, both the first refractive layer and the second refractive layer include:

[0017] At least one first refractive material layer and at least one second refractive material layer, wherein the first refractive material layer and the second refractive material layer are alternately stacked;

[0018] The refractive index of the first refractive material layer is different from that of the second refractive material layer.

[0019] As a further improvement of the embodiments of this application, the first refractive layer includes a plurality of first layer groups stacked in a direction perpendicular to the substrate. Each first layer group includes a first refractive material layer and a second refractive material layer. In the first layer group, the first refractive material layer and the second refractive material layer are stacked sequentially in a direction away from the induced transmission layer and towards the induced transmission layer.

[0020] The second refractive layer includes a plurality of second layer groups stacked in a direction perpendicular to the substrate. Each second layer group includes a first refractive material layer and a second refractive material layer. In the second layer group, the first refractive material layer and the second refractive material layer are stacked sequentially in a direction away from the induced transmission layer and towards the induced transmission layer.

[0021] As a further improvement to the embodiments of this application, in one of the first step portions or one of the fourth step portions, the optical thickness of each of the first refractive material layers is one-quarter of the target wavelength, and the optical thickness of each of the second refractive material layers is one-quarter of the target wavelength.

[0022] As a further improvement to the embodiments of this application, the induced transmission layer includes:

[0023] A first dielectric material layer, the metal layer, and a second dielectric material layer are sequentially stacked in a direction perpendicular to the substrate;

[0024] The thickness of the first dielectric material layer in the second step section at different heights is different, and the thickness of the second dielectric material layer in the third step section at different heights is different.

[0025] As a further improvement to the embodiments of this application, a first dielectric material layer of different thicknesses is used to tune light of different target wavelengths, and a second dielectric material layer of different thicknesses is used to tune light of different target wavelengths.

[0026] As a further improvement to the embodiments of this application, the plurality of filter channels are arranged in an array along a first direction and a second direction on the surface of the substrate;

[0027] The first direction and the second direction are parallel to the surface of the substrate, and the first direction and the second direction are perpendicular to each other.

[0028] As a further improvement to the embodiments of this application, the first refractive layer, the first dielectric material layer, and the metal layer are included. The second dielectric material layer and the second refractive layer are sequentially fabricated using a film patterning process.

[0029] The multispectral filter provided in this application utilizes a first refractive layer, an induced transmission layer, and a second refractive layer stacked sequentially. Incident light enters through the second refractive layer and is filtered by the first refractive layer to form a spectrum. The induced transmission layer is used for admittance matching of the metal layer, and the first and second refractive layers on either side of the induced transmission layer serve as antireflection coatings. By stacking the first refractive layer, the induced transmission layer, and the second refractive layer, good cutoff suppression and transmittance can be achieved, generating a high-resolution spectrum while reducing light energy loss.

[0030] In addition, in the multispectral filter provided in this application, the first refractive layer is distributed on the surface of the substrate, the induced transmission layer is distributed on the surface of the first refractive layer, and the second refractive layer is distributed on the surface of the induced transmission layer. By stacking the stepped portions of different heights in the above films, a filter channel that can be tuned to different target wavelengths is directly formed, which solves the problems of difficult processing technology and high cost of existing filters. Attached Figure Description

[0031] Figure 1 is a schematic diagram of a multispectral filter provided in one embodiment of this application;

[0032] Figure 2 is a schematic diagram of a filtering channel provided in one embodiment of this application;

[0033] Figure 3 is a schematic diagram of a filtering channel provided in one embodiment of this application;

[0034] Figure 4 is a schematic diagram of the induced transmission layer provided in one embodiment of this application.

[0035] Reference numerals: 10, substrate; 20, first refractive layer; 21, first refractive material layer; 22, second refractive material layer; 23, first step; 30, induced transmission layer; 31, first dielectric material layer; 32, metal layer; 33, second dielectric material layer; 34, second step; 35, third step; 40, second refractive layer; 41, fourth step; 50, filter channel. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0037] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0038] Spectral filters are instruments used for wavelength selection, choosing the desired target wavelength from a wide range of wavelengths. Light other than the target wavelength is filtered out and cannot pass through the filter. Spectral filters can be used for wavelength selection, noise filtering in optical amplifiers, gain equalization, optical multiplexing / demultiplexing, etc.

[0039] In the existing technology, commonly used filters include metal-dielectric Fabry-Perot filters and thin-film all-dielectric Fabry-Perot filters.

[0040] Among them, metal-dielectric Fabry-Perot filters typically do not have sideband passes. However, due to the large absorption of the metal film, the performance improvement of the filter is limited, resulting in a very low peak transmittance and low transmitted energy in the target wavelength range. If the peak transmittance is increased, the half-width will be sacrificed, resulting in a larger half-width, which makes the cutoff and passband shapes unusable. The filter channels will crosstalk, reducing the spectral resolution of the filter.

[0041] Thin-film all-dielectric Fabry-Perot filters are a common structure used in narrowband transmission filters, allowing for very narrow transmission bandwidths. However, their drawback is a very limited cutoff suppression range, preventing the formation of broadband transmission filters and confining the filter's filtering range to a finite area. Furthermore, in multispectral filters, the wider the spectrum and the more channels, the greater the design and manufacturing difficulty. For this reason, it is necessary to add cutoff filters to eliminate unnecessary bandwidth suppression. This additional method of adding cutoff filters results in a very high total number of layers, increasing both the manufacturing difficulty and cost.

[0042] Therefore, existing spectral filters cannot effectively balance bandwidth and transmittance, have limited suppression in the cutoff region, and also suffer from high production costs and complex manufacturing processes.

[0043] One embodiment of this application proposes a multispectral filter, as shown in FIG1, comprising a substrate 10, a first refractive layer 20, an induced transmission layer 30, and a second refractive layer 40. The first refractive layer 20 is distributed on the surface of the substrate 10 and is used to interfere with light of certain wavelengths. The first refractive layer 20 includes a plurality of first step portions 23, at least one of which has a different height in a direction perpendicular to the substrate 10. The induced transmission layer 30 is distributed on the surface of the first refractive layer 20 away from the substrate 10 and is used for admittance matching of the metal layer 32. The induced transmission layer 30 includes a plurality of second step portions 34, the metal layer 32, and a third step portion 35, at least two of which are perpendicular to the substrate 10. The heights of the three third steps 35 are different in the direction perpendicular to the substrate 10, and the heights of the two third steps 35 are different in the direction perpendicular to the substrate 10. The second refractive layer 40 is distributed on the surface of the induced transmission layer 30 away from the first refractive layer 20. The second refractive layer 40 is used to interfere with light of a certain wavelength. The second refractive layer 40 includes a plurality of fourth steps 41, and the heights of the two fourth steps 41 are different in the direction perpendicular to the substrate 10. A first step 23, a second step 34, a metal layer 32, a first third step 35 and a fourth step 41 are stacked in the direction perpendicular to the substrate to form a filter channel 50. The filter channels 50 of different heights are used to tune light of different target wavelengths.

[0044] The multispectral filter provided in this embodiment uses the first refractive layer 20 and the second refractive layer 40 as antireflection films for the induced transmission layer 30, eliminating the reflection of the equivalent admittance of the induced transmission layer 30, inducing the metal layer 32 to generate the maximum transmittance, and at the same time, the non-target wavelength region has good cutoff region suppression due to the reflection of the metal layer 32, which can take into account both good half-width and transmittance, and finally generate a high-resolution spectrum, while reducing light energy loss.

[0045] When a first step portion 23 of the first refractive layer 20, a second step portion 34 of the induced transmission layer 30, a metal layer 32, a third step portion 35, and a fourth step portion 41 of the second refractive layer 40 are stacked, a filter channel 50 is formed. The heights of the first step portion 23, the second step portion 34, the third step portion 35, and the fourth step portion 41 are set according to the target wavelength tuned in the filter channel 50.

[0046] It should be noted that the incident light is refracted in the first refractive layer 20 and the second refractive layer 40, causing interference of light within a certain wavelength range. The wavelength range of the interfering light varies depending on the height of the first step 23; similarly, the second refractive layer 40 also exhibits different interfering light ranges depending on the height of the fourth step 41. Therefore, the first step 23 and the fourth step 41 are configured with different thicknesses to accommodate different target wavelengths of light corresponding to different filter channels 50.

[0047] For ease of explanation, the side of the first refractive layer 20 closest to the substrate 10 is described as the bottom, and the side furthest from the substrate 10 is described as the top. The incident light enters from the top of the multispectral filter, passes through the filter channels 50 at different heights, and the target wavelength is transmitted to the substrate 10, forming a spectral distribution.

[0048] In this embodiment, the first refractive layer 20 is distributed entirely on the surface of the substrate 10. The first refractive layer 20 has a stepped structure and is divided into multiple first stepped portions 23 according to different heights. Similarly, the induced transmission layer 30 is distributed entirely on the surface of the first refractive layer 20. The induced transmission layer 30 has a stepped structure and includes second stepped portions 34 and third stepped portions 35, which are distinguished according to different heights. Inside the induced transmission layer 30, along a direction perpendicular to the substrate, the second stepped portions 34, the metal layer 32, and the third stepped portions 35 are stacked. The second refractive layer 40 is distributed entirely on the surface of the induced transmission layer 30. The second refractive layer 40 has a stepped structure and is divided into multiple fourth stepped portions 41 according to different heights. Therefore, multiple filter channels 50 perpendicular to the substrate 10 are formed by stacking the first refractive layer 20, the induced transmission layer 30, and the second refractive layer 40, which are distributed parallel to the substrate 10. This reduces production costs and the complexity of the manufacturing process. In addition, compared with other splicing forms of filter channels 50, in this embodiment, adjacent filter channels 50 are formed solely by the step difference of the film layer structure itself, which significantly improves the connection accuracy between adjacent filter channels 50.

[0049] In one specific embodiment of this application, the substrate 10 is made of a transparent material, and the spectrum generated by the multiple filter channels 50 is transmitted to the lower side of the substrate 10 to form a spectral map. The substrate 10 only serves as a support base for integrating the multiple filter channels 50. In another specific embodiment of this application, the substrate 10 is provided with multiple light sensors, and each light sensor corresponds to one of the filter channels 50. Therefore, the spectrum generated by the multiple filter channels 50 is transmitted to the computer system through the light sensors.

[0050] In the embodiments of this application, as shown in FIG3, the first refractive layer 20 and the second refractive layer 40 both include at least one first refractive material layer 21 and at least one second refractive material layer 22, and the first refractive material layer 21 and the second refractive material layer 22 are alternately stacked; the refractive index of the first refractive material layer 21 is different from that of the second refractive material layer 22.

[0051] In a specific implementation, the first refractive material layer 21 is a high refractive material layer with a high refractive index, and the second refractive material layer 22 is a low refractive material layer with a low refractive index, with the high refractive material layer and the low refractive index material layer being stacked alternately.

[0052] In an embodiment of this application, as shown in FIG3, the first refractive layer 20 includes a plurality of first layer groups stacked in a direction perpendicular to the substrate. Each first layer group includes a first refractive material layer 21 and a second refractive material layer 22. In the first layer group, the first refractive material layer 21 and the second refractive material layer 22 are stacked sequentially from the direction away from the induced transmission layer 30 to the direction close to the induced transmission layer 30.

[0053] The second refractive layer 40 includes a plurality of second layer groups stacked in a direction perpendicular to the substrate 10. Each second layer group includes a first refractive material layer 21 and a second refractive material layer 22. In the second layer group, the first refractive material layer 21 and the second refractive material layer 22 are stacked sequentially in a direction away from the induced transmission layer 30 and towards the induced transmission layer 30.

[0054] The first refractive material layer 21 and the second refractive material layer 22 in the first refractive layer 20 and the second refractive layer 40 are symmetrically distributed on both sides of the induced transmission layer 30. The high-refractive-index material layer and the low-refractive-index material layer in the first refractive layer 20, which are in reverse order, are used to adjust the reflection phase or broaden the reflection bandwidth and optimize the interference conditions. After the incident light is transmitted through the induced transmission layer 30, the propagation path in the first refractive layer 20 is mirror-symmetrical with that in the second refractive layer 40.

[0055] In embodiments of this application, in a first step portion 23 or a fourth step portion 41, the optical thickness of each first refractive material layer 21 is one-quarter of the target wavelength, and the optical thickness of each second refractive material layer 22 is one-quarter of the target wavelength.

[0056] In other embodiments of this application, the first refractive layer 20 includes a plurality of first layer groups stacked in a direction perpendicular to the substrate 10, each first layer group including a first refractive material layer 21 and a second refractive material layer 22, the second refractive material layer 22 and the first refractive material layer 21 being stacked sequentially in a direction away from the induced transmission layer 30 and towards the induced transmission layer 30; the second refractive layer 40 includes a plurality of second layer groups stacked in a direction perpendicular to the substrate 10, each second layer group including a first refractive material layer 21 and a second refractive material layer 22, the second refractive material layer 22 and the first refractive material layer 21 being stacked sequentially in a direction away from the induced transmission layer 30 and towards the induced transmission layer 30.

[0057] In a specific embodiment of this application, the first refractive material layer 21 with a higher refractive index is titanium dioxide, and the second refractive material layer 22 with a lower refractive index is silicon dioxide.

[0058] In the embodiments of this application, as shown in Figures 3 and 4, the induced transmission layer 30 includes a first dielectric material layer 31, a metal layer 32, and a second dielectric material layer 33 sequentially stacked in a direction perpendicular to the substrate 10. The thickness of the first dielectric material layer 31 in the second step portion 34 at different heights is different, and the thickness of the second dielectric material layer 33 in the third step portion 35 at different heights is different. The first dielectric material layer 31 and the second dielectric material layer 33 have high light transmittance, and the metal layer 32 has excellent cutoff region suppression. The first dielectric material layer 31, the metal layer 32, and the second dielectric layer 33 are stacked to form the induced transmission layer 30. The admittance of the metal layer is matched to the first dielectric material layer 31 and the second dielectric layer 33, so that the induced transmission layer 30 simultaneously has excellent light transmittance and excellent cutoff region suppression, and the light of the tuned target wavelength has a good half-width. In the filter channels 50 with different target wavelengths, the thickness of the first dielectric material layer 31 is different, and the thickness of the second dielectric material layer 33 is different, thus tuning the light of different target wavelengths.

[0059] It should be noted that the induced transmission layer 30 is composed of three types of film layers stacked together, wherein the first dielectric material layer 31 has a stepped structure and the second dielectric material layer 33 has a stepped structure. The first dielectric material layer 31 includes a plurality of second stepped portions 34, at least two of which have different heights, and the second dielectric material layer 33 includes a plurality of third stepped portions 35, at least two of which have different heights.

[0060] In a specific embodiment of this application, the first dielectric material layer 31 and the second dielectric material layer 33 are made of dielectric transparent materials, such as SiO or TiO, and the metal layer 32 is made of silver or aluminum, etc.

[0061] In the embodiments of this application, the metal layer 32 in the second step portion 34 at different heights has the same thickness. The metal layer 32 is used to improve the ability of the cutoff region suppression of the induced transmission layer 30 without affecting the transmitted target wavelength. At the same time, in order to avoid the light transmittance of the metal layer 32 being too low, the metal layer 32 needs to be set to an extremely thin thickness. Therefore, an extremely thin metal layer 32 of the same thickness is provided in each filter channel 50 to improve the cutoff region suppression ability of the induced transmission layer 30 while minimizing the impact on the light transmittance of the induced transmission layer 30.

[0062] In the embodiments of this application, first dielectric material layers 31 of different thicknesses are used to tune light of different target wavelengths, and second dielectric material layers 33 of different thicknesses are used to tune light of different target wavelengths.

[0063] The thickness of the first dielectric material layer 31 and the thickness of the second dielectric material layer 33 are set according to the target wavelength preset for tuning at the filter channel. Therefore, the target wavelength transmitted in different filter channels 50 is different, and the thickness of the first dielectric material layer 31 and the thickness of the second dielectric material layer 33 will also change accordingly.

[0064] In a specific embodiment of this application, the optical thickness of the first dielectric material layer 31 is a, the optical thickness of the second dielectric material layer 33 is a, and the target wavelength of the filter channel 50 is b, wherein a≤1 / 4b.

[0065] The optical thickness of the first dielectric material layer 31 and the second dielectric material layer 33 is designed to be less than one-quarter of the target wavelength. The sum of the optical thickness of the first dielectric material layer 31 and the adjacent second refractive material layer 22 is one-quarter of the target wavelength. Similarly, the sum of the optical thickness of the second dielectric material layer 33 and the adjacent second refractive material layer 22 is one-quarter of the target wavelength.

[0066] In a specific embodiment of this application, the relationship between the optical thickness a of the first dielectric material layer 31 and the second dielectric material layer 33 and the target wavelength b of the filter channel 50 can be: a = 1 / 4b, a = 1 / 8b, a = 1 / 16b, etc.

[0067] In a specific embodiment of this application, the stacked structure in the multispectral filter can be represented as: (HL)ma(M)-metal-a(M)-(LH)m;

[0068] Wherein, H is the first refractive material layer 21, L is the second refractive material layer 22, m represents the number of overlaps, a represents the optical thickness coefficient of the first dielectric material layer 31 or the second dielectric material layer 33, and M is the dielectric transparent material.

[0069] In the embodiments of this application, as shown in FIG1, X represents the first direction and Y represents the second direction. Multiple filter channels 50 are arrayed on the surface of the substrate 10 along the first and second directions. The first and second directions are parallel to the surface of the substrate and perpendicular to each other. The filter channels 50 array is distributed on the substrate 10. When incident light simultaneously enters the multispectral filter, the generated multiple target wavelengths form a spectrum distributed in an array.

[0070] In a specific implementation, there are m filter channels 50 arrays distributed in the first direction and n filter channels 50 arrays distributed in the second direction, with the filter channels 50 distributed in an m*n form.

[0071] In the embodiments of this application, among the plurality of filter channels 50 arranged in an array along the first direction, the filter channel 50 located at the center position has the largest height, and the extension length of the filter channels 50 distributed to both sides along the first direction gradually decreases. The filter is distributed in a form that is high in the middle and low on both sides, which facilitates subsequent packaging and improves the stability of the filter structure.

[0072] In a specific embodiment of this application, when multiple filter channels 50 are distributed in an m*n manner, the filter channel 50 at the diagonal center of the rectangular array has the longest extension length, and the extension length of the filter channels 50 distributed from this filter channel 50 along the first and second directions gradually decreases, and the multiple filter channels 50 form a sloping structure that is high in the middle and low around the edges.

[0073] In the embodiments of this application, the first refractive layer 20, the first dielectric material layer 31, the metal layer 32, the second dielectric material layer 33, and the second refractive layer 40 are sequentially fabricated using a film patterning process, forming a stepped layer structure.

[0074] In specific implementations, the film patterning process includes mask vacuum evaporation, mask photolithography, electron beam etching, 3D printing, laser direct writing, or nanoimprinting.

[0075] In this specific embodiment, using overlay or overlay plating, a first refractive material layer 21 covering the entire surface is first fabricated on the substrate 10, followed by a second refractive material layer 22 covering the entire surface. This process is repeated in the order of the first refractive material layer 21 to the second refractive material layer 22 to form a first refractive layer 20 covering the entire surface. A first dielectric material layer 31 is then fabricated on the first refractive layer 20, followed by a metal layer 32. A second dielectric material layer 33 is then fabricated on the metal layer 32 to form an induced transmission layer 30 covering the entire surface. The second refractive material layer 22 and the first refractive material layer 21 are then fabricated sequentially on the induced transmission layer. The number of times the second refractive material layer 22 and the first refractive material layer 21 are stacked is the same as the number of times they are stacked in the first refractive layer 20. Finally, the stacking order and number of the first refractive material layer 21 and the second refractive material layer 22 are mirror-distributed with the induced transmission layer 30 as the center.

[0076] The multispectral filter proposed in the embodiments of this application has a wider cutoff region suppression compared to a filter with all-dielectric transmission processing; compared to a filter with stacked metal and dielectric layers, the light energy absorption capacity of the induced transmission layer 30 is less than that of the metal layer, resulting in higher transmittance and narrower bandwidth, thus improving spectral resolution.

[0077] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; under the concept of this application, the above embodiments or technical features of different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0078] The embodiments described herein are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments described herein should be included within the protection scope of this application.

Claims

1. A multispectral filter, characterized in that, include: Base; A first refractive layer is distributed on the surface of the substrate, and the first refractive layer is used to interfere with light of a certain wavelength. The first refractive layer includes a plurality of first stepped portions, at least two of which have different heights in a direction perpendicular to the substrate; an induced transmission layer is distributed on the surface of the first refractive layer away from the substrate; the induced transmission layer includes a plurality of second stepped portions, a metal layer, and a plurality of third stepped portions, at least two of which have different heights in a direction perpendicular to the substrate, and at least two of which have different heights in a direction perpendicular to the substrate; a second refractive layer is distributed on the surface of the induced transmission layer away from the first refractive layer, and the second refractive layer is used to interfere with light of a certain wavelength; the second refractive layer includes a plurality of fourth stepped portions, at least two of which have different heights in a direction perpendicular to the substrate; one first stepped portion, one second stepped portion, a metal layer, one third stepped portion, and one fourth stepped portion are stacked in a direction perpendicular to the substrate to form a filter channel; The filter channels at different heights are used to tune light to different target wavelengths.

2. The multispectral filter according to claim 1, characterized in that, Both the first refractive layer and the second refractive layer include: at least one first refractive material layer and at least one second refractive material layer, wherein the first refractive material layer and the second refractive material layer are stacked alternately; the refractive index of the first refractive material layer is different from the refractive index of the second refractive material layer.

3. The multispectral filter according to claim 2, characterized in that, The first refractive layer includes a plurality of first layer groups stacked in a direction perpendicular to the substrate. Each first layer group includes a first refractive material layer and a second refractive material layer. In the first layer group, the first refractive material layer and the second refractive material layer are stacked sequentially in a direction away from the induced transmission layer and towards the induced transmission layer. The second refractive layer includes a plurality of second layer groups stacked in a direction perpendicular to the substrate. Each second layer group includes a first refractive material layer and a second refractive material layer. In the second layer group, the first refractive material layer and the second refractive material layer are stacked sequentially in a direction away from the induced transmission layer and towards the induced transmission layer.

4. The multispectral filter according to claim 2, characterized in that, In one of the first step sections or one of the fourth step sections, the optical thickness of each of the first refractive material layers is one-quarter of the target wavelength, and the optical thickness of each of the second refractive material layers is one-quarter of the target wavelength.

5. The multispectral filter according to claim 1, characterized in that, The induced transmission layer includes: a first dielectric material layer, the metal layer, and a second dielectric material layer sequentially stacked in a direction perpendicular to the substrate; the thickness of the first dielectric material layer in the second step portion at different heights is different, and the thickness of the second dielectric material layer in the third step portion at different heights is different.

6. The multispectral filter according to claim 2, characterized in that, First dielectric material layers of different thicknesses are used to tune light to different target wavelengths, and second dielectric material layers of different thicknesses are used to tune light to different target wavelengths.

7. The multispectral filter according to claim 1, characterized in that, The plurality of filter channels are arranged in an array along a first direction and a second direction on the surface of the substrate; the first direction and the second direction are parallel to the surface of the substrate and perpendicular to the first direction and the second direction.

8. The multispectral filter according to claim 5, characterized in that, The first refractive layer, the first dielectric material layer, the metal layer, the second dielectric material layer, and the second refractive layer are sequentially fabricated using a film patterning process.

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