Detection metasurface, spectral polarization detection method and construction method of metasurface

Abstract

The invention relates to the technical field of micro-nano optics, and particularly provides a detection metasurface, a spectral polarization detection method and a construction method of the metasurface. The detection metasurface comprises a substrate and dielectric cylinders arranged on the surface of the substrate. Wherein the phase parameter of the dielectric cylinder meets a preset detection condition; the preset detection condition comprises that the positions of the light with different wavelengths or / and different polarization states on the focusing focus of the focal plane are different. Because the phase parameter of the dielectric cylinder meets the preset detection condition, incident light with different wavelengths or / and different polarization states can be focused at different positions of a focal plane based on the detection metasurface, and then spectral information and polarization information contained in the incident light are determined based on the position and light intensity of a focusing point. Therefore, spectrum information and polarization information can be obtained in real time through single detection based on the detection metasurface, real-time polarization spectrum detection is achieved, the information obtaining dimension is improved, and meanwhile the detection efficiency and the dynamic object detection capacity are improved.

Description

Technical Field

[0001] The present application relates to the field of micro-nano optical technologies, and more particularly, to a detection metasurface, a spectral polarization detection method, and a method for constructing a metasurface. Background Art

[0002] Light waves can carry a large amount of information, including multiple dimensions such as wavelength, phase, amplitude, polarization, etc. Detecting different properties of light has always been a research hotspot. Spectral detection can obtain the spectral information of substances and is used in fields such as environmental monitoring, resource exploration, gas identification, etc. Polarization detection can obtain the polarization information of an object, and based on the polarization information, determine the surface topography, shape, material composition, etc. of the object, so as to realize functions such as target recognition and defect detection of the object.

[0003] Traditional spectral polarization detection systems usually obtain the spectral information and polarization information of incident light based on various optical elements such as filters, gratings, and polarization elements. The structure of traditional spectral polarization detection systems is complex and large in size, which is not conducive to the miniaturization and integration of optical detection devices. A metasurface is composed of sub-wavelength scale structures arranged on a two-dimensional plane, and can realize the regulation of the inherent properties of light (phase, amplitude, polarization, etc.). It has the advantages of light weight, miniaturization, and integration, and is suitable for solving the problems existing in traditional optical systems. However, existing metasurface detection technologies can only achieve spectral detection or polarization detection separately, and cannot obtain all spectral information and polarization information based on a single detection, resulting in poor detection ability of existing metasurface detection technologies for dynamic objects. Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a detection metasurface, a spectral polarization detection method, and a method for constructing a metasurface to solve the above technical problems.

[0005] In a first aspect, the embodiments of the present application provide a detection metasurface, where the metasurface includes: a substrate, and dielectric columns disposed on the surface of the substrate;

[0006] Wherein, the phase parameter of the dielectric column satisfies a preset detection condition;

[0007] Wherein, the preset detection condition includes: the positions of the focusing foci of light with different wavelengths or / and different polarization states on the focal plane are different.

[0008] In the above implementation process, the detection metasurface includes a substrate and dielectric columns disposed on the surface of the substrate; wherein, the phase parameters of the dielectric columns satisfy a preset detection condition; the preset detection condition includes: the positions of the focusing foci of light with different wavelengths or / and different polarization states on the focal plane are different. Since the phase parameters of the dielectric columns satisfy the preset detection condition, based on this detection metasurface, incident light with different wavelengths or / and different polarization states can be focused at different positions on the focal plane. Then, based on the positions and light intensities of the focusing foci, the spectral information and polarization information contained in the incident light can be determined. Therefore, based on this detection metasurface, the spectral information and polarization information of the incident light can be obtained in real time through a single detection, realizing real-time polarization spectroscopy detection, while improving the information acquisition dimension, the detection efficiency, and the detection ability for dynamic objects.

[0009] Optionally, in an embodiment of the present application, the metasurface includes: a plurality of polarization detection regions respectively used to implement different polarization state detections; wherein, the preset detection condition specifically includes: within each of the polarization detection regions, the positions of the focusing foci of light with different wavelengths on the focal plane are different.

[0010] In the above implementation process, since the metasurface includes a plurality of polarization detection regions respectively used to implement different polarization state detections, incident light with different polarization states can be focused on different regions of the focal plane based on the plurality of polarization detection regions; since within each polarization detection region, the positions of the focusing foci of light with different wavelengths on the focal plane are different, the spectral information and polarization information contained in the incident light can be determined based on the positions and light intensities of the focusing foci in different regions of the focal plane. In addition, since the metasurface includes a plurality of polarization detection regions respectively used to implement different polarization state detections, each polarization detection region only responds to one type of polarized light, thereby improving the extinction ratio of polarization detection, reducing the crosstalk between different polarizations, and improving the accuracy of the polarization detection result based on this detection metasurface.

[0011] Optionally, in an embodiment of the present application, the polarization detection regions include: a first detection region for implementing X-line polarization detection, a second detection region for implementing Y-line polarization detection, a third detection region for implementing 45°-line polarization detection, and a fourth detection region for implementing right-handed circular polarization detection.

[0012] In the above implementation process, based on the first detection area for implementing X-ray polarization detection, the horizontal polarization intensity can be obtained; based on the second detection area for implementing Y-ray polarization detection, the vertical polarization intensity can be obtained; based on the third detection area for implementing 45° linear polarization detection, the inclined polarization intensity can be obtained; based on the fourth detection area for implementing right-handed circular polarization detection, the right-handed polarization intensity can be obtained; and then all Stokes vectors can be obtained based on the horizontal polarization intensity, vertical polarization intensity, inclined polarization intensity, and right-handed polarization intensity, so as to realize real-time full Stokes polarization spectroscopy detection.

[0013] Optionally, in the embodiments of the present application, the polarization detection area further includes: a fifth detection area for implementing 135° linear polarization detection and a sixth detection area for implementing left-handed circular polarization detection.

[0014] Optionally, in the embodiments of the present application, the phase parameter of the dielectric column in the linear polarization detection area includes: a transmission phase parameter; the phase parameter of the dielectric column in the circular polarization detection area includes: a transmission phase parameter and a geometric phase parameter; wherein, the linear polarization detection area includes the first detection area, the second detection area, the third detection area, and the fifth detection area; the circular polarization detection area includes the fourth detection area and the sixth detection area.

[0015] In the above implementation process, by adjusting the transmission phase parameter of the dielectric column in the linear polarization detection area, or adjusting the transmission phase parameter and / or geometric phase parameter of the dielectric column in the circular polarization detection area, it is possible to adjust the position of the focusing focus of light with different wavelengths or / and different polarization states on the focal plane, so that the phase parameter of the dielectric column meets the preset detection conditions.

[0016] Optionally, in the embodiments of the present application, the phase response of all dielectric columns can cover the range of 0-2π.

[0017] In the above implementation process, the phase response of all dielectric columns can cover the range of 0-2π, which can ensure that the detection metasurface has a sufficient phase response range.

[0018] In a second aspect, the embodiments of the present application provide a spectroscopic polarization detection method, and the method includes: using the detection metasurface as described in any item of the first aspect above to obtain the spectroscopic information and / or polarization information of the light to be measured.

[0019] Optionally, in the embodiments of the present application, when the metasurface includes: a first detection area for realizing X-ray polarization detection, a second detection area for realizing Y-ray polarization detection, a third detection area for realizing 45° linear polarization detection, and a fourth detection area for realizing right-handed circular polarization detection, the method specifically includes: using the detection metasurface to obtain the focal position of the light to be measured; using the detection metasurface to obtain the horizontal polarization intensity I of the light to be measured after passing through the first detection area, the second detection area, the third detection area, and the fourth detection area respectively X 、vertical polarization intensity I Y 、oblique polarization intensity I A and right-handed polarization intensity I R ; determining the spectral information of the light to be measured according to the focal position; according to the horizontal polarization intensity I X 、the vertical polarization intensity I Y 、the oblique polarization intensity I A 、the right-handed polarization intensity I R and determining the polarization information S of the light to be measured

[0020] In the above implementation process, since the metasurface includes multiple polarization detection areas respectively used to realize different polarization state detections, incident light with different polarization states can be focused on different areas of the focal plane based on the multiple polarization detection areas. Since within each polarization detection area, the positions of the focal points of light with different wavelengths on the focal plane are different, the spectral information contained in the incident light can be determined based on the positions of the focal points in different areas of the focal plane; and all Stokes vectors can be obtained based on the horizontal polarization intensity, vertical polarization intensity, oblique polarization intensity, and right-handed polarization intensity, realizing real-time full Stokes polarization spectroscopy detection. In addition, since the metasurface includes multiple polarization detection areas respectively used to realize different polarization state detections, each polarization detection area only responds to one kind of polarized light, thereby improving the extinction ratio of polarization detection, reducing the crosstalk between different polarizations, and improving the accuracy of the polarization detection result based on the detection metasurface

[0021] In a third aspect, the embodiments of the present application further provide a method for constructing a detection metasurface, where the detection metasurface includes a substrate and dielectric columns disposed on the surface of the substrate

[0022] The method includes

[0023] Determining the target phase distribution of the detection metasurface according to preset detection conditions; where the preset detection conditions include: the positions of the focal points of light with different wavelengths or / and different polarization states on the focal plane are different

[0024] Determine the dielectric pillars disposed on the surface of the substrate according to the target phase distribution.

[0025] Optionally, in the embodiments of the present application, the determining the dielectric pillars disposed on the surface of the substrate according to the target phase distribution includes: determining at least one group of alternative dielectric groups from the alternative dielectric units according to the target phase distribution; calculating the phase difference between the phase parameters of the alternative dielectric units at all positions on the detection metasurface and the target phase distribution within a preset incident wavelength range according to the phase parameters of the alternative dielectric units in each alternative dielectric group; and determining the alternative dielectric units included in the alternative dielectric group with the smallest phase difference as the dielectric pillars disposed on the surface of the substrate.

[0026] In the above implementation process, the smaller the phase difference is, the smaller the gap between the phase distribution of the detection metasurface at each wavelength and the target phase distribution is. By determining the alternative dielectric units included in the alternative dielectric group with the smallest phase difference as the dielectric pillars disposed on the surface of the substrate, the detection metasurface can better focus light of different wavelengths to different focal points, improve the focusing effect, reduce the crosstalk between different wavelengths, and thus improve the accuracy and precision of the spectral detection results.

[0027] The beneficial effects of the present application at least include: Since the phase parameters of the dielectric pillars satisfy the preset detection conditions (the positions of the focusing focal points of light of different wavelengths or / and different polarization states on the focal plane are different), based on this detection metasurface, incident light of different wavelengths or / and different polarization states can be focused at different positions on the focal plane, and then based on the positions and light intensities of the focusing focal points, the spectral information and polarization information contained in the incident light can be determined. Therefore, based on this detection metasurface, the spectral information and polarization information of the incident light can be obtained in real time through a single detection, realizing real-time polarization spectroscopy detection, while improving the dimension of information acquisition, improving the detection efficiency and the detection ability for dynamic objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 FIG. 1 is a schematic structural diagram of a detection metasurface provided by an embodiment of the present application;

[0030] Figure 2 FIG. 2 is a schematic diagram of the detection results of a detection metasurface provided by an embodiment of the present application;

[0031] Figure 3 Schematic diagram of a metasurface unit structure for detecting a metasurface provided by an embodiment of the present application;

[0032] Figure 4 Flow schematic diagram of a construction method for detecting a metasurface provided by an embodiment of the present application;

[0033] Figure 5 Schematic diagram of the light intensity detection result of a metasurface for detecting a metasurface provided by an embodiment of the present application;

[0034] Figure 6 Schematic diagram of the polarization detection result of a metasurface for detecting a metasurface provided by an embodiment of the present application. Detailed implementation manners

[0035] Hereinafter, embodiments of the technical solutions of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, and thus are only examples and cannot be used to limit the protection scope of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality of" means two or more, unless otherwise specifically defined.

[0038] Please refer to Figure 1 , Figure 1 Schematic diagram of the structure of a metasurface for detecting a metasurface provided by an embodiment of the present application. Figure 1 What is shown is a partial schematic diagram of the detecting metasurface 10. The dielectric columns 102 included in the detecting metasurface 10 may be more than Figure 1 the number shown. The detecting metasurface 10 includes: a substrate 101 and dielectric columns 102 disposed on the surface of the substrate 101;

[0039] Among them, the phase parameters of the dielectric columns 102 satisfy a preset detection condition;

[0040] Among them, the preset detection condition includes: the positions of the focusing foci of light with different wavelengths or / and different polarization states on the focal plane are different.

[0041] Among them, the actual detection area of the detecting metasurface 10 may be circular, square, rectangular, etc. Figure 1Only the case where the actual detection area is square is shown exemplarily. The phase parameters of the dielectric column 102 may include transmission phase and / or geometric phase. The focusing phase of the detection metasurface 10 can be designed by utilizing the transmission phase and / or geometric phase of the dielectric column 102 to meet the preset detection conditions. That is, by designing the transmission phase and / or geometric phase of the dielectric column 102, the detection metasurface 10 has different focusing phases for light of different wavelengths or / and different polarization states, so as to focus the incident light of different wavelengths or / and different polarization states at different positions on the focal plane for realizing real-time spectral and polarization detection. Since the phase parameters of the dielectric column 102 meet the preset detection conditions, based on this, the detection metasurface 10 can focus the incident light of different wavelengths or / and different polarization states at different positions on the focal plane, and then determine the spectral information and polarization information contained in the incident light based on the position and light intensity of the focusing focus. Therefore, based on this detection metasurface 10, the spectral information and polarization information of the incident light can be obtained in real time through a single detection, realizing real-time polarization spectroscopy detection, while improving the information acquisition dimension, the detection efficiency and the detection ability for dynamic objects.

[0042] In some alternative embodiments, the detection metasurface 10 includes: a plurality of polarization detection regions respectively for realizing detection of different polarization states; wherein, the preset detection conditions specifically include: within each of the polarization detection regions, the positions of the focusing foci of light of different wavelengths on the focal plane are different.

[0043] Among them, the detection metasurface 10 may include a first detection region for realizing detection of X-line polarization, a second detection region for realizing detection of Y-line polarization, a third detection region for realizing detection of 45°-line polarization, and a fourth detection region for realizing detection of right-handed circular polarization. It may also include a first detection region for realizing detection of X-line polarization, a second detection region for realizing detection of Y-line polarization, a third detection region for realizing detection of 45°-line polarization, a fourth detection region for realizing detection of right-handed circular polarization, a fifth detection region for realizing detection of 135°-line polarization, and a sixth detection region for realizing detection of left-handed circular polarization. The number of the polarization detection regions included in the detection metasurface 10 and the specific implementation manner of each polarization detection region can both be adjusted according to the actual application situation, and the present application does not make specific limitations thereon. Figure 1It is only exemplarily shown that the number of polarization detection regions is 4, and the detection metasurface 10 specifically includes "a first detection region for realizing the detection of X-line polarized light, a second detection region for realizing the detection of Y-line polarized light, a third detection region for realizing the detection of 45°-line polarized light, and a fourth detection region for realizing the detection of right-handed circularly polarized light". Since the detection metasurface 10 includes multiple polarization detection regions respectively for realizing the detection of different polarization states, incident light with different polarization states can be focused on different regions of the focal plane based on the multiple polarization detection regions; since within each polarization detection region, the positions of the focusing foci of light with different wavelengths on the focal plane are different, the spectral information and polarization information contained in the incident light can be determined based on the positions and light intensities of the focusing foci in different regions of the focal plane. In addition, since the detection metasurface 10 includes multiple polarization detection regions respectively for realizing the detection of different polarization states, each polarization detection region only responds to one kind of polarized light (for example, the first detection region for realizing the detection of X-line polarized light only responds to X-line polarized light, that is, only focuses X-line polarized light and diverges orthogonal polarized light), thereby improving the extinction ratio of polarization detection, reducing the crosstalk between different polarizations, and improving the accuracy of the polarization detection result based on this detection metasurface.

[0044] In some alternative embodiments, the polarization detection regions include: a first detection region for realizing the detection of X-line polarized light, a second detection region for realizing the detection of Y-line polarized light, a third detection region for realizing the detection of 45°-line polarized light, and a fourth detection region for realizing the detection of right-handed circularly polarized light.

[0045] Among them, based on the first detection region for realizing the detection of X-line polarized light, the horizontal polarization light intensity I X can be obtained, and based on the second detection region for realizing the detection of Y-line polarized light, the vertical polarization light intensity I Y can be obtained. Based on the third detection region for realizing the detection of 45°-line polarized light, the inclined polarization light intensity I A can be obtained, and based on the fourth detection region for realizing the detection of right-handed circularly polarized light, the right-handed polarization light intensity I R can be obtained; and then based on the horizontal polarization light intensity I X , the vertical polarization light intensity I Y , the inclined polarization light intensity I A , the right-handed polarization light intensity I R and the full Stokes vector S of the incident light is determined. Among them, the Stokes vector S can be described by four light intensity parameters S 0 , S 1 , S 2 , S 3 . S 0 represents the total light intensity, S 1, S 2 , S 3 Together describe the polarization state of light, S 1 , S 2 , S 3 respectively represent the intensity differences of three pairs of orthogonal polarization states (i.e., I X and I Y , I A and I B , I R and I L ), I L represents the left-handed circular polarization intensity, I A represents the 45° oblique polarization intensity, I B represents the 135° oblique polarization intensity. Based on the above derivation, only four polarization states need to be detected to calculate the complete Stokes vector. In this way, the structure of the detection metasurface 10 can be made more compact, which is beneficial to the miniaturization and integration of the detection metasurface.

[0046] Please refer to Figure 2 , Figure 2 which is a schematic diagram of the detection result of a detection metasurface provided by an embodiment of the present application. Figure 2 Shows the situation where "the actual detection area of the detection metasurface 10 is circular, and the detection metasurface 10 includes a first detection area for realizing the detection of X-line polarization, a second detection area for realizing the detection of Y-line polarization, a third detection area for realizing the detection of 45° line polarization, and a fourth detection area for realizing the detection of right-handed circular polarization". Specifically, Figure 2 The left side shows a schematic diagram of the imaging process based on the detection metasurface 10, Figure 2 The right side shows a schematic diagram of the imaging result based on the detection metasurface 10 (it should be noted that the actual imaging result only includes the peripheral focused foci). After being focused by the detection metasurface 10, a ring is formed on the focal plane. Based on the rectangular coordinate system, the ring can be divided into four regions, and each region corresponds to a different polarization state, realizing the detection of 4 set polarization states. There are still multiple foci in the same region (the number of foci can be 21, 26, 31 or other reasonable values, and the number of foci in the same region is related to the actual detected spectral channels), and the multiple foci correspond to different wavelength lights of the same polarization state.

[0047] In some alternative embodiments, the polarization detection area further includes: a fifth detection area for realizing the detection of 135° line polarization, and a sixth detection area for realizing the detection of left-handed circular polarization.

[0048] Among them, based on the fifth detection area for realizing the detection of 135° line polarization, the 135° oblique polarization intensity I B, based on the sixth detection region for implementing the detection of left-handed circularly polarized light, the left-handed polarized light intensity I can be obtained. L ; and then based on the horizontal polarized light intensity I X , the vertical polarized light intensity I Y , the oblique polarized light intensity I A and I B , the right-handed polarized light intensity I R , the left-handed polarized light intensity I L and determine the full Stokes vector S of the incident light.

[0049] Among them, the polarization detection region may also include: the first detection region for implementing the detection of X linearly polarized light, the second detection region for implementing the detection of Y linearly polarized light, the fifth detection region for implementing the detection of 135° linearly polarized light, and the sixth detection region for implementing the detection of left-handed circularly polarized light.

[0050] In some alternative embodiments, the phase parameters of the dielectric columns in the linear polarization detection region include: transmission phase parameters; the phase parameters of the dielectric columns in the circular polarization detection region include: transmission phase parameters and geometric phase parameters; among them, the linear polarization detection region includes the first detection region, the second detection region, the third detection region, and the fifth detection region; the circular polarization detection region includes the fourth detection region and the sixth detection region.

[0051] Please refer to Figure 3 , Figure 3 , which is a schematic diagram of the metasurface unit structure for detecting a metasurface provided by an embodiment of the present application. As Figure 3 shown, the metasurface unit structure includes a dielectric column and a dielectric substrate from top to bottom. The period of the unit structure is P (that is, the center distance between two adjacent dielectric columns). The length of the dielectric column is L, the width is W, and the height is H.

[0052] Among them, for the dielectric pillars in the linearly polarized detection region, the transmission phase can be adjusted by changing the length L or width W of the dielectric pillar, and then the phase parameters of the dielectric pillar can be adjusted. For the dielectric pillars in the circularly polarized detection region, the transmission phase can be adjusted by changing the length L or width W of the dielectric pillar, and then the phase parameters of the dielectric pillar can be adjusted; alternatively, the geometric phase can be adjusted by changing the rotation angle of the dielectric pillar, and then the phase parameters of the dielectric pillar can be adjusted. Due to the dispersion effect, the transmission phase response of the dielectric pillar will change with the change of the incident light wavelength. When simulating the phase response of the dielectric pillar structure, the response data at different wavelengths can be extracted, and the focusing effect (or wave phase difference) under different phase parameters can be used as the evaluation criterion to find the arrangement of dielectric pillars that can obtain the best imaging effect. Among them, the length L of the dielectric pillar is less than the period P of the unit structure, the width W of the dielectric pillar is also less than the period P of the unit structure, and the period P of the unit structure is less than the working wavelength of the detection metasurface (the wavelength of the light to be measured); for the value of the height H of the dielectric pillar, it is necessary to ensure that when sweeping the parameters of W and L, the phase response of the dielectric pillar can cover 2π. The specific values of the parameters such as the length L, width W, height H of the dielectric pillar and the period P of the unit structure can all be adjusted according to the spectral range to be detected, and the present application does not make specific limitations on this.

[0053] In some alternative embodiments, the phase responses of all the dielectric pillars can cover the range of 0 - 2π.

[0054] Among them, the phase responses of all the dielectric pillars can cover the range of 0 - 2π, which can ensure that the detection metasurface has a sufficient phase response range. For example, the phase responses between eight different dielectric pillars can form an arithmetic sequence with a common difference of

[0055] The embodiment of the present application also provides a spectral polarization detection method, which includes: using the detection metasurface as described in any item of the first aspect above to obtain the spectral information and / or polarization information of the light to be measured.

[0056] Among them, since the phase parameters of the dielectric pillars 102 in the detection metasurface 10 as described in any item of the first aspect above satisfy the preset detection conditions, based on the detection metasurface 10, the incident light with different wavelengths or / and different polarization states can be focused at different positions on the focal plane, and then based on the position and light intensity of the focused focal point, the spectral information and polarization information contained in the incident light can be determined. Therefore, based on this detection metasurface 10, the spectral information and polarization information of the incident light can be obtained in real time through a single detection, realizing real-time polarization spectroscopy detection, while improving the dimension of information acquisition, improving the detection efficiency and the detection ability for dynamic objects.

[0057] In some alternative embodiments, when the metasurface includes: a first detection area for realizing X-ray polarization detection, a second detection area for realizing Y-ray polarization detection, a third detection area for realizing 45° linear polarization detection, and a fourth detection area for realizing right-handed circular polarization detection, the method specifically includes:

[0058] Using the detection metasurface, obtain the focal position of the light to be measured;

[0059] Using the detection metasurface, obtain the horizontal polarization intensity I of the light to be measured after passing through the first detection area, the second detection area, the third detection area, and the fourth detection area respectively X , the vertical polarization intensity I Y , the oblique polarization intensity I A and the right-handed polarization intensity I R ;

[0060] According to the focal position, determine the spectral information of the light to be measured;

[0061] According to the horizontal polarization intensity I X , the vertical polarization intensity I Y , the oblique polarization intensity I A , the right-handed polarization intensity I R and determine the polarization information S of the light to be measured.

[0062] Wherein, to avoid repetition, the specific implementation manners of the above steps can refer to the relevant descriptions of the detection metasurface 10 in the above text. As described above, since the detection metasurface 10 includes multiple polarization detection areas respectively for realizing different polarization state detections, incident light with different polarization states can be focused on different areas of the focal plane based on the multiple polarization detection areas. Since within each polarization detection area, the positions of the focal points of light with different wavelengths on the focal plane are different, the spectral information contained in the incident light can be determined based on the positions of the focal points in different areas of the focal plane; and all Stokes vectors can be obtained based on the horizontal polarization intensity, vertical polarization intensity, oblique polarization intensity, and right-handed polarization intensity, realizing real-time full Stokes polarization spectroscopy detection. In addition, since the detection metasurface 10 includes multiple polarization detection areas respectively for realizing different polarization state detections, each polarization detection area only responds to one kind of polarized light, thereby improving the extinction ratio of polarization detection, reducing the crosstalk between different polarizations, and improving the accuracy of the polarization detection result based on the detection metasurface 10.

[0063] Please refer to Figure 4 , Figure 4Schematic flowchart of a method for constructing a detection metasurface provided by an embodiment of the present application. The method for constructing the detection metasurface is used to construct a detection metasurface 10 including a substrate 101 and dielectric columns 102 disposed on the surface of the substrate 101. The method for constructing the detection metasurface may include the following steps:

[0064] S201. Determine the target phase distribution of the detection metasurface according to preset detection conditions; wherein, the preset detection conditions include: the positions of the focusing foci of light with different wavelengths or / and different polarization states on the focal plane are different;

[0065] S202. Determine the dielectric columns disposed on the surface of the substrate according to the target phase distribution.

[0066] Among them, the target phase distribution that can make the positions of the focusing foci of light with different wavelengths or / and different polarization states on the focal plane different can be first determined based on simulation or theoretical derivation. Based on the target phase distribution, corresponding dielectric columns are selected for metasurface construction.

[0067] In some alternative embodiments, S202. Determine the dielectric columns disposed on the surface of the substrate according to the target phase distribution, including: determining at least one group of alternative dielectric groups from the alternative dielectric units according to the target phase distribution; calculating the wave phase difference between the phase parameters of the alternative dielectric units at all positions on the detection metasurface within a preset incident wavelength range and the target phase distribution according to the phase parameters of the alternative dielectric units in each alternative dielectric group; determining the alternative dielectric units included in the alternative dielectric group with the smallest wave phase difference as the dielectric columns disposed on the surface of the substrate.

[0068] Among them, it can be based on

[0069] Calculate the ideal phase for the detection metasurface to achieve the designed function, that is, the target phase at position (x, y λ i represents the incident wavelength, f represents the imaging focal length, (x i , y i ) represents the imaging position of light with an incident wavelength of λ i on the focal plane.

[0070] Then based on Calculate the wave phase difference between the phase parameters of the alternative dielectric units at all positions on the detection metasurface within a preset incident wavelength range and the target phase distribution φ i (x, y) represents the phase parameter of the alternative dielectric unit within a preset incident wavelength range, and the smaller the wave phase difference the smaller the gap between the phase distribution of the detection metasurface at each wavelength and the target phase distribution. The wave phase difference The smallest alternative medium group can better focus light of different wavelengths to different focal points, improve the focusing effect, reduce the crosstalk between different wavelengths, and thus improve the accuracy and precision of the spectral detection results.

[0071] The detection metasurface provided in this application can be applied to the long-wave infrared band, optical band, terahertz band, microwave band, etc. To verify the spectral polarization detection performance of the detection metasurface provided in this application, this application uses electromagnetic simulation software to simulate the performance of the unit structure, and uses software for phase optimization, result simulation and data processing. Specifically, taking the working band as 9-12 μm in the long-wave infrared, the detection metasurface is selected as the structure shown in Figure 1 and the manufacturing material is silicon as an example, the light incidence of the detection metasurface at different polarizations and different wavelengths is simulated by software.

[0072] Please refer to Figure 5 , Figure 5 which is a schematic diagram of the light intensity detection result of a detection metasurface provided by an embodiment of this application. Among them, the incident light has four different properties: X-polarized light with a wavelength of 9.7 μm, Y-polarized light with a wavelength of 10.3 μm, 45° polarized light with a wavelength of 10.9 μm, and right-handed circularly polarized light with a wavelength of 11.5 μm. Figure 5 From top to bottom in

[0073] Please refer to Figure 6 , Figure 6 which is a schematic diagram of the polarization detection result of a detection metasurface provided by an embodiment of this application. To reflect the advantages of the detection metasurface provided in this application in the field of polarization detection, its polarization detection error is continuously verified. The normalized Stokes vector calculated according to the focal point light intensity after the incident light of different polarization states passes through the detection metasurface and is focused is simulated by software. Figure 6From left to right, they represent the polarization detection results of four regions of the detection metasurface (from left to right: the first detection region for realizing the detection of X-line polarization, the second detection region for realizing the detection of Y-line polarization, the third detection region for realizing the detection of 45°-line polarization, and the fourth detection region for realizing the detection of right-handed circular polarization). And based on the normalized Stokes vectors of different regions, the four set polarization states can be accurately obtained (where X-pol represents the X-line polarization state, Y-pol represents the Y-line polarization state, 45°-pol represents the 45°-line polarization state, and R-pol represents the right-handed circular polarization state), verifying the polarization detection performance of this design. Among them, taking the X-polarized incident light as an example, the normalized Stokes vector detected is [1, 0.968, 0.022, -0.021] T ; the polarization detection error for the X-polarized incident light is 4.4%. And as Figure 6 shown, the polarization detection errors for the other three polarization states are 5.41%, 1.09%, and 3.05% respectively. The average error of the four polarization states is 3.49%, thus verifying the advantages of the detection metasurface provided by this application in the field of polarization detection.

[0074] In several embodiments provided by the embodiments of this application, it should be understood that the disclosed structures and methods can also be implemented in other ways. The structural embodiments described above are only illustrative. For example, the flowcharts and block diagrams in the drawings show the possible implementation architectures, functions, and operations of the structures or methods according to multiple embodiments of the embodiments of this application. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code. A module, a program segment, or a part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order from that marked in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0075] In addition, in each embodiment of the embodiments of this application, each functional module can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0076] The above description is only an optional implementation manner of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the embodiments of the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the embodiments of the present application.

Claims

1. A detection metasurface, characterized in that: The metasurface comprises: a substrate, and a dielectric column arranged on the surface of the substrate; Wherein, the phase parameter of the dielectric column satisfies a preset detection condition; Wherein, the preset detection conditions include: the positions of the focusing points of lights with different wavelengths and / or different polarization states in the focal plane are different.

2. The supersurface according to claim 1, characterized in that The metasurface comprises: a plurality of polarization detection regions respectively used to realize different polarization state detection; The preset detection conditions specifically include: in each of the polarization detection regions, the positions of the focusing points of light of different wavelengths on the focal plane are different.

3. The supersurface according to claim 2, characterized in that in, The polarization detection area includes: a first detection area for realizing X-line polarization detection, a second detection area for realizing Y-line polarization detection, a third detection area for realizing 45° linear polarization detection, and a fourth detection area for realizing right-handed circular polarization detection.

4. The supersurface according to claim 3, characterized in that in, The polarization detection area also includes: a fifth detection area for detecting 135° linear polarization, and a sixth detection area for detecting left-handed circular polarization.

5. The supersurface according to claim 4, characterized in that in, The phase parameters of the dielectric column in the linear polarization detection area include: transmission phase parameters; the phase parameters of the dielectric column in the circular polarization detection area include: transmission phase parameters and geometric phase parameters; The linear polarization detection area includes the first detection area, the second detection area, the third detection area and the fifth detection area; the circular polarization detection area includes the fourth detection area and the sixth detection area.

6. The supersurface according to any one of claims 1 to 5, characterized in that: in, The phase response of all dielectric rods can cover the range of 0-2π.

7. A spectral polarization detection method, characterized in that: The method comprises: using the detection metasurface as described in any one of claims 1 to 6 above to obtain spectral information and / or polarization information of the light to be measured.

8. The method according to claim 7, characterized in that In the case where the metasurface includes: a first detection area for realizing X-line polarization detection, a second detection area for realizing Y-line polarization detection, a third detection area for realizing 45° linear polarization detection, and a fourth detection area for realizing right-handed circular polarization detection, the method specifically includes: Using the detection metasurface, obtaining the focal position of the light to be measured; Using the detection metasurface, the horizontal polarization intensity I of the light to be measured after passing through the first detection area, the second detection area, the third detection area, and the fourth detection area is obtained. X , vertical polarized light intensity I Y , tilted polarized light intensity I A And the right-hand polarized light intensity I R ; Determining the spectrum information of the light to be measured according to the focus position; According to the horizontal polarized light intensity I X , the vertical polarized light intensity I Y , the tilted polarized light intensity I A , the right-handed polarized light intensity I R as well as The polarization information S of the light to be measured is determined.

9. A method for constructing a detection metasurface, characterized in that: The detection metasurface includes a substrate and a dielectric column arranged on the surface of the substrate; The method comprises: Determine the target phase distribution of the detection metasurface according to preset detection conditions; wherein the preset detection conditions include: the positions of the focusing points of lights of different wavelengths and / or different polarization states in the focal plane are different; According to the target phase distribution, a dielectric column disposed on the surface of the substrate is determined.

10. The method according to claim 9, characterized in that The step of determining a dielectric column disposed on the surface of the substrate according to the target phase distribution includes: Determining at least one candidate medium group from the candidate medium units according to the target phase distribution; Calculating the phase difference between the phase parameters of the candidate medium units at all positions on the detection metasurface in a preset incident wavelength range and the target phase distribution according to the phase parameters of each candidate medium unit in the candidate medium group; The candidate medium unit included in the candidate medium group with the smallest wave phase difference is determined to be a medium column arranged on the surface of the substrate.

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