Method and system for forming long-wave and very-long-wave infrared all-silicon anti-reflection metasurface

Abstract

The invention provides a long-wave and very-long-wave infrared all-silicon anti-reflection metasurface forming method and system. The method comprises the steps that S1, optical information of a high-purity silicon material is collected; s2, solving a complex refractive index parameter of the high-purity silicon material according to the optical information; s3, establishing a metasurface model according to the complex refractive index parameters; s4, obtaining a reflectivity curve of the high-purity silicon column structure based on the metasurface model; s5, obtaining the average reflectivity according to the reflectivity curve, and selecting the corresponding physical parameters of the high-purity silicon column structure under the condition that the average reflectivity is minimum; periodically arranging the physical parameters on a high-purity silicon substrate so as to form a target metasurface; the high-purity silicon column structure provided by the invention and the high-purity silicon substrate are made of the same material, so that the problems of thermal stress mismatch and easy falling caused by introduction of a new material are avoided, and the high-purity silicon column structure can be adapted to detectors working at normal temperature and low temperature.

Description

Technical Field

[0001] The present invention belongs to the field of supersurface technology, and in particular, relates to a method and system for composing a long-wave and very-long-wave infrared all-silicon anti-reflection supersurface. Background Art

[0002] Infrared detectors working in long-wave and very long-wave infrared, that is, with a wavelength of 8-28μm, have very important applications in the field of remote sensing. For example, the James Webb Telescope used for astronomical detection, in which the infrared instrument is equipped with long-wave and very long-wave detectors for exploring the origin of the universe.

[0003] The semiconductor materials commonly used in such detectors have a high refractive index. Therefore, when infrared radiation is incident on the interface between air and the detector, it will produce strong reflection, thereby reducing the core technical indicators of the detector such as response and sensitivity. Taking the blocked impurity band, or BIB detector, carried by infrared instruments as an example, when the detector is working, the radiation signal passes through the first interface, which is the air-high purity silicon substrate interface, where the refractive index of air is n. air =1, the refractive index of the ideal high-purity silicon substrate n si It is 3.42, which is quite different from the other two. According to the Fresnel equation, the reflection generated on the single-layer interface is 30%.

[0004] Therefore, anti-reflection technology is often used to reduce the surface reflection of such detectors. Currently, the commonly used anti-reflection technology mostly adopts the method of multi-layer optical film, and in order to achieve effective anti-reflection, the film thickness h is determined by the wavelength λ and the refractive index n of the film material. The relationship between the three must satisfy the relationship: h = λ / (n×4). For long waves and very long waves, h is usually in the micron level. However, thicker films are easy to fall off during processing, and there are thermal stresses between multi-layer films. Therefore, anti-reflection technology based on multi-layer films in the long-wave and very long-wave infrared bands has great difficulties and limitations.

[0005] As an artificial micro-nanostructure, metasurface can flexibly control light waves on a subwavelength scale. With the development of metasurface technology, optical anti-reflection can be achieved by introducing metasurfaces on the device surface. When long-wave and very long-wave infrared radiation is incident, it first interacts with the micro-nanostructure on the device surface. Therefore, by designing matching micro-nanostructures, the coupling efficiency between the incident light and the metasurface can be increased, thereby coupling more radiation light to the device functional layer to achieve effective anti-reflection and ultimately improve device performance. Summary of the invention

[0006] In view of the defects in the prior art, the object of the present invention is to provide a method and system for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface.

[0007] A method for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface according to the present invention comprises:

[0008] Step S1: collecting optical information of high-purity silicon material;

[0009] Step S2: Calculating the complex refractive index parameter of the high-purity silicon material according to the optical information;

[0010] Step S3: establishing a metasurface model according to the complex refractive index parameter;

[0011] Step S4: obtaining a reflectivity curve of a high-purity silicon pillar structure based on the supersurface model;

[0012] Step S5: According to the reflectivity curve, the average reflectivity is obtained and the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity are selected; the physical parameters are periodically arranged on the high-purity silicon substrate to form a target metasurface.

[0013] Preferably, in step S1, the optical information is the transmission curve, reflection curve and absorption curve of the high-purity silicon material in the long-wave and very long-wave infrared bands;

[0014] The mathematical expressions of the reflection curve, absorption curve and transmission curve are respectively as follows from top to bottom:

[0015]

[0016] Among them, T exp represents the transmission curve; R0 represents the single interface reflectivity; a0 represents the absorptivity of the high-purity silicon substrate; R exp Represents the reflection curve; A exp Represents the absorption curve.

[0017] Preferably, in step S2, the complex refractive index parameter includes a real part of the complex refractive index and an imaginary part of the complex refractive index; the real part of the complex refractive index is the refractive index, and the imaginary part of the complex refractive index is the extinction coefficient;

[0018] The mathematical expression of the refractive index is:

[0019]

[0020] Where R0 represents the single interface reflectivity; n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air;

[0021] The mathematical expression of the extinction coefficient is:

[0022]

[0023] Among them, a0 represents the absorption rate of high-purity silicon substrate, ω represents the angular frequency, z represents the thickness of uniform medium, k represents the extinction coefficient, e represents the natural constant, and c represents the speed of light.

[0024] Preferably, in step S4, the size of the high-purity silicon column structure should satisfy the expression:

[0025]

[0026] Among them, n eff Refractive index, n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air;

[0027]

[0028] Where h is the thickness; λ is the wavelength;

[0029] Preferably, the step S5 includes:

[0030] Step S5.1: Calculate the reflectivity curves of different periods P, different side lengths L, and different thicknesses h by using the finite difference time domain method, and let the calculation results form a parameter group;

[0031] Step S5.2: Evaluate and obtain the average reflectivity according to the parameter group;

[0032] Step S5.3: selecting the physical parameters of the high-purity silicon column structure corresponding to the case where the average reflectivity is the minimum; and periodically arranging the physical parameters on the high-purity silicon substrate;

[0033] Step S5.4: Based on the high-purity silicon substrate, a high-purity silicon column structure periodically distributed on a single-side surface is formed to form a target super surface;

[0034] In step S5.2, the mathematical expression of the average reflectivity is:

[0035]

[0036] Among them, R avg represents the average reflectivity, λ i represents the wavelength point, r i is the reflectivity corresponding to the wavelength point, λ1=8μm, λ n =28μm.

[0037] According to the present invention, a long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system is provided, comprising:

[0038] Module M1: Collecting optical information of high-purity silicon materials;

[0039] Module M2: Calculating the complex refractive index parameter of the high-purity silicon material according to the optical information;

[0040] Module M3: establishing a metasurface model according to the complex refractive index parameters;

[0041] Module M4: obtaining a reflectivity curve of a high-purity silicon pillar structure based on the supersurface model;

[0042] Module M5: According to the reflectivity curve, the average reflectivity is obtained and the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity are selected; the physical parameters are periodically arranged on the high-purity silicon substrate to form a target metasurface.

[0043] Preferably, in the module M1, the optical information is the transmission curve, reflection curve and absorption curve of the high-purity silicon material in the long-wave and very long-wave infrared bands;

[0044] The mathematical expressions of the reflection curve, absorption curve and transmission curve are respectively as follows from top to bottom:

[0045]

[0046] Among them, T exp represents the transmission curve; R0 represents the single interface reflectivity; a0 represents the absorptivity of the high-purity silicon substrate; R exp Represents the reflection curve; A exp Represents the absorption curve.

[0047] Preferably, in the module M2, the complex refractive index parameter includes a real part of the complex refractive index and an imaginary part of the complex refractive index; the real part of the complex refractive index is the refractive index, and the imaginary part of the complex refractive index is the extinction coefficient;

[0048] The mathematical expression of the refractive index is:

[0049]

[0050] Where R0 represents the single interface reflectivity; n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air;

[0051] The mathematical expression of the extinction coefficient is:

[0052]

[0053] Among them, a0 represents the absorption rate of high-purity silicon substrate, ω represents the angular frequency, z represents the thickness of uniform medium, k represents the extinction coefficient, e represents the natural constant, and c represents the speed of light.

[0054] Preferably, in the module M4, the size of the high-purity silicon column structure should satisfy the expression:

[0055]

[0056] Among them, n eff Refractive index, n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air;

[0057]

[0058] Wherein, h represents thickness and λ represents wavelength.

[0059] Preferably, the module M5 includes:

[0060] Module M5.1: Calculate the reflectivity curves of different periods P, different side lengths L, and different thicknesses h by using the finite difference time domain method, and make the calculation results form a parameter group;

[0061] Module M5.2: Evaluate and obtain the average reflectivity according to the parameter group;

[0062] Module M5.3: Select the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity; and periodically arrange the physical parameters on the high-purity silicon substrate;

[0063] Module M5.4: Based on the high-purity silicon substrate, a high-purity silicon column structure periodically distributed on a single-side surface is formed to form a target super surface;

[0064] In the module M5.2, the mathematical expression of the average reflectivity is:

[0065]

[0066] Among them, R avg represents the average reflectivity, λ i represents the wavelength point, r i is the reflectivity corresponding to the wavelength point, λ1=8μm, λ n =28μm.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] 1. The metasurface anti-reflection technology provided by the invention has a wide working bandwidth and low production cost.

[0069] 2. The all-silicon anti-reflection super surface provided by the present invention can be directly integrated with the detector silicon substrate, which reduces the processing complexity and is conducive to the integrated development of the device.

[0070] 3. The high-purity silicon column structure provided by the present invention is made of the same material as the high-purity silicon substrate, thus avoiding the problem of thermal stress mismatch and easy falling off caused by the introduction of new materials, and can be adapted to detectors operating at room temperature and low temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0072] Figure 1 A three-dimensional schematic diagram (left) and a top view (right) of the long-wave and very long-wave infrared all-silicon anti-reflection supersurface unit structure provided by the present invention; the high-purity silicon column is a square column;

[0073] Figure 2 A schematic diagram of a multi-layer interface transflection transmission model when measuring a high-purity silicon transflection curve provided by the present invention;

[0074] Figure 3 A schematic diagram of a multi-layer interface transflection transmission model when measuring a high-purity silicon transflection curve provided by the present invention;

[0075] Figure 4 The complex refractive index curve of the high-purity silicon material provided by the present invention, wherein n and k represent the real part of the complex refractive index, i.e. the refractive index, and the imaginary part of the complex refractive index, i.e. the extinction coefficient, respectively;

[0076] Figure 5 A schematic diagram of the average reflectivity of the high-purity silicon square pillar structure provided by the present invention in the long-wave and very long-wave infrared bands under different parameter groups;

[0077] Figure 6 A schematic diagram of the optimal reflection curve of the high-purity silicon square pillar structure provided by the present invention in the long-wave and very long-wave infrared bands and the reflection curve of the high-purity silicon single-layer surface;

[0078] Figure 7 The normalized electric field intensity distribution results at different times on the y=0μm plane provided by the present invention; wherein, a) is the electric field intensity distribution on the y=0μm plane when the infrared pulse light source is incident into the air and has not yet interacted with the metasurface; b) is the electric field intensity distribution on the y=0μm plane when the infrared pulse light source interacts with the metasurface; c) is the electric field intensity distribution on the y=0μm plane after the infrared pulse light source interacts with the metasurface. DETAILED DESCRIPTION

[0079] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0080] The long-wave and very-long-wave infrared all-silicon anti-reflection super surface of the embodiment of the present invention can reduce the reflection of the incident long-wave and very-long-wave infrared light beams and increase the transmission of long-wave and very-long-wave infrared light beams, filling the gap of the all-silicon anti-reflection super surface in the long-wave and very-long-wave infrared bands. Integrating the present invention on the detector can reduce the strong reflection generated when the infrared radiation is incident on the interface between the air and the detector, thereby improving the core technical indicators such as the detector response and sensitivity. The existing anti-reflection technology uses a multi-layer thin film method and has problems such as narrow bandwidth and easy falling off; in contrast, directly processing a silicon column structure with the same substrate material as the detector high-purity silicon substrate can more easily achieve a wide bandwidth and is more conducive to integrated applications.

[0081] Step 1: Test the transmission, reflection and absorption curves of high-purity silicon materials in the long-wave and very long-wave infrared bands;

[0082] Step 2: According to the actual measurement, a multi-layer interface transflection transmission model is used to calculate the real part of the complex refractive index of the material, that is, the refractive index, that is, n, and the imaginary part of the complex refractive index, that is, the extinction coefficient, that is, k;

[0083] Step 3: The high-purity silicon material parameters in the metasurface simulation use the calculated complex refractive index, and the all-silicon metasurface model is established in the simulation software according to the equivalent homogeneous medium theory;

[0084] Step 4: Simulate and calculate the reflectivity curves of high-purity silicon pillar structures of different sizes when long-wave and very long-wave infrared beams are incident;

[0085] Step 5: Calculate the average reflectivity of high-purity silicon pillar structures of different sizes in the long-wave and very long-wave infrared bands, select the physical parameters of the silicon pillars corresponding to the minimum average reflectivity, and arrange them periodically on the high-purity silicon substrate;

[0086] The long-wave and very-long-wave infrared all-silicon anti-reflection super surface is composed of a high-purity silicon substrate and a high-purity silicon column structure periodically distributed on a single side surface thereof.

[0087] Specifically, the period of the high-purity silicon column structure should be less than one fifth of the maximum operating wavelength.

[0088] Specifically, the periodic high-purity silicon column structure can be regarded as an equivalent medium.

[0089] Specifically, the height of the high-purity silicon column structure and the media on both sides depend on the refractive index and wavelength of high-purity silicon and air.

[0090] The embodiment of the present invention designs the long-wave and very-long-wave infrared all-silicon anti-reflection super surface composed of a high-purity silicon substrate and a high-purity silicon column structure periodically distributed on its single-side surface, thereby achieving the function of reducing the reflectivity of the incident long-wave and very-long-wave infrared light beams and increasing the transmittance of the long-wave and very-long-wave infrared light beams.

[0091] In the embodiment of the present invention, the high-purity silicon column structure is a square column, and the long-wave and very long-wave infrared bands are 8-28 μm.

[0092] The entire metasurface is made of high-purity silicon material, so accurate high-purity silicon material parameters must be obtained before subsequent simulation of the entire high-purity silicon metasurface can be performed. During the actual test of the high-purity silicon substrate, the infrared beam will pass through the air-high-purity silicon-air materials in sequence, such as Figure 3 As shown, there are two interfaces at this time, so the measured transmission T exp , reflection R exp and absorption A exp The curve is the effect of multiple transmission, reflection and absorption superposition. Assuming that the single interface reflectivity of air-high purity silicon is R0 and the absorptivity of high purity silicon substrate with thickness h0 is a0, according to the multi-layer interface transflection transmission model, the measured reflection curve R exp , Absorption curve A exp And the transmission curve T exp The expressions are:

[0093]

[0094] Among them, T exp represents the transmission curve; R0 represents the single interface reflectivity; a0 represents the absorptivity of the high-purity silicon substrate; R exp Represents the reflection curve; A exp Represents the absorption curve.

[0095] According to formula (1), R0(λ) and α0(λ) at different wavelengths were solved by programming in Matlab software.

[0096] According to the Fresnel equation, the relationship between the reflectivity and refractive index on a single-layer interface is expressed mathematically as follows:

[0097]

[0098] Where R0 represents the single interface reflectivity; n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air;

[0099] According to the Beer-Lambert Law, the light intensity I(z) of the angular frequency ω and the light intensity I0 after passing through the uniform medium is related to the extinction coefficient k and the thickness z of the uniform medium. The mathematical expression is:

[0100]

[0101] Among them, I(z) is the light intensity after passing through the uniform medium; I0 is the light intensity; ω is the angular frequency; z is the thickness of the uniform medium; k is the extinction coefficient; e is the natural constant; c is the speed of light;

[0102] The absorption rate a0 of the high-purity silicon substrate can be expressed according to formula (3):

[0103]

[0104] Therefore, according to the measured transmission T exp , reflection R exp and absorption A exp Curve, R0 and a0 can be calculated using formula (1), and then the refractive index n and extinction coefficient k of high-purity silicon material can be calculated according to formula (2) and formula (4). The refractive index n and extinction coefficient k of the derived material are as follows: Figure 4 The calculated complex refractive index is imported into the simulation software for the subsequent design of long-wave and very long-wave infrared all-silicon anti-reflection supersurface.

[0105] like Figure 1 As shown, a single high-purity silicon square column structure is placed on a high-purity silicon substrate to form a supersurface unit, the unit structure period is P, the side length of the high-purity silicon column is L, and the thickness of the high-purity silicon column is h.

[0106] When the period P is less than one fifth of the maximum operating wavelength, the high-purity silicon column structure is relatively small compared to the wavelength, and the high-purity silicon column structure layer can be regarded as an equivalent uniform medium. By changing the size of the high-purity silicon column structure, the equivalent refractive index n of the equivalent uniform medium layer can be changed. eff .

[0107] To reduce reflection, the structural dimensions of high-purity silicon columns should meet the following conditions:

[0108]

[0109] Among them, n eff Refractive index, n si Represents the refractive index of high-purity silicon substrate; n air Represents the refractive index of air; the symbol “·” represents a multiplication sign;

[0110]

[0111] Where h is the thickness; λ is the wavelength;

[0112] Since the long-wave and very long-wave infrared bands described in the embodiment of the present invention are 8-28 μm and the band range is wide, it is necessary to scan different physical parameters of the high-purity silicon column structure and then select the average reflectivity R in the range of 8-28 μm. avg The parameter group corresponding to the minimum value.

[0113] Based on the derived complex refractive index of high-purity silicon material, the finite difference time domain method, namely FiniteDifference Time Domain, referred to as FDTD method, is used to calculate the reflectivity curves of different periods P, different side lengths L, and different thicknesses h. Due to processing restrictions, the minimum line width is set to no less than 2μm. Therefore, the scanning parameter step of the thickness h is set to 0.1μm and the scanning parameter range is 2.5-3.5μm; the scanning parameter step of the side length L is set to 0.1μm and the scanning parameter range is 3.2-4.5μm; the interval between the period P and the side length L is set to 2μm, for a total of 154 parameter groups.

[0114] Since the calculation results are the reflectivity scatter points r(λ) in the 8-28μm band with wavelength changes under different parameter groups, the average reflectivity R is evaluated. avg The integral of r(λ) over the wavelength within the band should be calculated first and then divided by the wavelength range. The calculation formula is as follows:

[0115]

[0116] Among them, R avg represents the average reflectivity, r i is i The corresponding reflectivity at the wavelength point, λ1=8μm, λ n =28μm.

[0117] The calculated average reflectivity of the high-purity silicon square pillar structure in the long-wave and very long-wave infrared bands under different parameter groups is as follows: Figure 5 The minimum average reflectivity of the metasurface in the 8-28 μm band is 4.2%, and the corresponding optimal parameter group is period P = 5.4 μm, side length L = 3.4 μm, and thickness h = 3 μm.

[0118] like Figure 6 As shown, the reflection curve of the metasurface under the optimal parameter set is lower than 10% in most bands within 8-28 μm, while the reflectivity of a high-purity silicon single-layer surface is about 30%.

[0119] An electric field monitor is set in the simulation to observe the normalized total electric field intensity distribution at different times on the y=0 μm plane. Figure 7 a), b) and c) are arranged in chronological order, which fully reflects the electric field intensity distribution of the infrared pulse light source from the air incident, interaction with the high-purity silicon column structure layer and penetration through the high-purity silicon structure layer. Figure 7 As can be seen from c), after the infrared pulse light source interacts with the high-purity silicon column structure layer, only a small amount of the light source is reflected into the air, and most of the light source enters the high-purity silicon substrate layer.

[0120] Therefore, the all-silicon anti-reflection super surface designed by the embodiment of the present invention can achieve the function of reducing the reflection of infrared light beams in a wide band of 8-28 μm, and the average reflectivity in the wide band is 4.2%.

[0121] The present invention also provides a long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system, which can be realized by executing the process steps of the long-wave and very long-wave infrared all-silicon anti-reflection super surface composition method, that is, those skilled in the art can understand the long-wave and very long-wave infrared all-silicon anti-reflection super surface composition method as a preferred implementation mode of the long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system.

[0122] According to the present invention, a long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system is provided, comprising:

[0123] Module M1: Collecting optical information of high-purity silicon materials;

[0124] Module M2: Calculating the complex refractive index parameter of the high-purity silicon material according to the optical information;

[0125] Module M3: establishing a metasurface model according to the complex refractive index parameters;

[0126] Module M4: obtaining a reflectivity curve of a high-purity silicon pillar structure based on the supersurface model;

[0127] Module M5: According to the reflectivity curve, the average reflectivity is obtained and the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity are selected; the physical parameters are periodically arranged on the high-purity silicon substrate to form a target metasurface.

[0128] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0129] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0130] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface, characterized in that: include: Step S1: collecting optical information of high-purity silicon material; Step S2: Calculating the complex refractive index parameter of the high-purity silicon material according to the optical information; Step S3: establishing a metasurface model according to the complex refractive index parameter; Step S4: obtaining a reflectivity curve of a high-purity silicon pillar structure based on the supersurface model; Step S5: According to the reflectivity curve, the average reflectivity is obtained and the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity are selected; the physical parameters are periodically arranged on the high-purity silicon substrate to form a target metasurface.

2. The method for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface according to claim 1, characterized in that: In the step S1, the optical information is the transmission curve, reflection curve and absorption curve of the high-purity silicon material in the long-wave and very long-wave infrared bands; The mathematical expressions of the reflection curve, absorption curve and transmission curve are respectively as follows from top to bottom: Among them, T exp represents the transmission curve; R0 represents the single interface reflectivity; a0 represents the absorptivity of the high-purity silicon substrate; R exp Represents the reflection curve; A exp Represents the absorption curve.

3. The method for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface according to claim 2, characterized in that: In step S2, the complex refractive index parameter includes a real part of the complex refractive index and an imaginary part of the complex refractive index; the real part of the complex refractive index is the refractive index, and the imaginary part of the complex refractive index is the extinction coefficient; The mathematical expression of the refractive index is: Where R0 represents the single interface reflectivity; n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air; The mathematical expression of the extinction coefficient is: Among them, a0 represents the absorption rate of high-purity silicon substrate, ω represents the angular frequency, z represents the thickness of uniform medium, k represents the extinction coefficient, e represents the natural constant, and c represents the speed of light.

4. The method for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface according to claim 3, characterized in that: In step S4, the size of the high-purity silicon column structure should satisfy the expression: Among them, n eff Refractive index, n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air; Where h is the thickness; λ is the wavelength; 5. The method for forming a long-wave and very long-wave infrared all-silicon anti-reflection super surface according to claim 4, characterized in that: In the step S5, it includes: Step S5.1: Calculate the reflectivity curves of different periods P, different side lengths L, and different thicknesses h by using the finite difference time domain method, and let the calculation results form a parameter group; Step S5.2: Evaluate and obtain the average reflectivity according to the parameter group; Step S5.3: selecting the physical parameters of the high-purity silicon column structure corresponding to the case where the average reflectivity is the minimum; and periodically arranging the physical parameters on the high-purity silicon substrate; Step S5.4: Based on the high-purity silicon substrate, a high-purity silicon column structure periodically distributed on a single-side surface is formed to form a target super surface; In step S5.2, the mathematical expression of the average reflectivity is: Among them, R avg represents the average reflectivity, λ i represents the wavelength point, r i is the reflectivity corresponding to the wavelength point, λ1=8μm, λ n =28μm.

6. A long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system, characterized in that: include: Module M1: Collecting optical information of high-purity silicon materials; Module M2: Calculating the complex refractive index parameter of the high-purity silicon material according to the optical information; Module M3: establishing a metasurface model according to the complex refractive index parameters; Module M4: obtaining a reflectivity curve of a high-purity silicon pillar structure based on the supersurface model; Module M5: According to the reflectivity curve, the average reflectivity is obtained and the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity are selected; the physical parameters are periodically arranged on the high-purity silicon substrate to form a target metasurface.

7. The long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system according to claim 6 is characterized in that: In the module M1, the optical information is the transmission curve, reflection curve and absorption curve of the high-purity silicon material in the long-wave and very long-wave infrared bands; The mathematical expressions of the reflection curve, absorption curve and transmission curve are respectively as follows from top to bottom: Among them, T exp represents the transmission curve; R0 represents the single interface reflectivity; a0 represents the absorptivity of the high-purity silicon substrate; R exp Represents the reflection curve; A exp Represents the absorption curve.

8. The long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system according to claim 7 is characterized in that: In the module M2, the complex refractive index parameter includes a real part of the complex refractive index and an imaginary part of the complex refractive index; the real part of the complex refractive index is the refractive index, and the imaginary part of the complex refractive index is the extinction coefficient; The mathematical expression of the refractive index is: Where R0 represents the single interface reflectivity; n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air; The mathematical expression of the extinction coefficient is: Among them, a0 represents the absorption rate of high-purity silicon substrate, ω represents the angular frequency, z represents the thickness of uniform medium, k represents the extinction coefficient, e represents the natural constant, and c represents the speed of light.

9. The long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system according to claim 8, characterized in that: In the module M4, the size of the high-purity silicon column structure should satisfy the expression: Among them, n eff Refractive index, n si Represents the refractive index of high-purity silicon substrate; n air represents the refractive index of air; Wherein, h represents thickness and λ represents wavelength.

10. The long-wave and very long-wave infrared all-silicon anti-reflection super surface composition system according to claim 9, characterized in that: The module M5 includes: Module M5.1: Calculate the reflectivity curves of different periods P, different side lengths L, and different thicknesses h by using the finite difference time domain method, and make the calculation results form a parameter group; Module M5.2: Evaluate and obtain the average reflectivity according to the parameter group; Module M5.3: Select the physical parameters of the high-purity silicon column structure corresponding to the minimum average reflectivity; and periodically arrange the physical parameters on the high-purity silicon substrate; Module M5.4: Based on the high-purity silicon substrate, a high-purity silicon column structure periodically distributed on a single-side surface is formed to form a target super surface; In the module M5.2, the mathematical expression of the average reflectivity is: Among them, R avg represents the average reflectivity, λ i represents the wavelength point, r i is the reflectivity corresponding to the wavelength point, λ1=8μm, λ n =28μm.

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