Anti-symmetric chiral metasurface and application and verification method for phase and amplitude regulation

Abstract

The present invention discloses an antisymmetric chiral metasurface and its applications and verification methods for phase and amplitude regulation, belonging to the field of micro-nano optics. It includes a surface layer, an intermediate layer, and a backplane layer arranged in sequence from top to bottom. The surface layer is composed of a left semi-circular ring and a right semi-circular ring. At both ends of the side of the left semi-circular ring facing the right semi-circular ring, they are bent towards the center of the circle to form a first protrusion and a second protrusion. One end of the side of the right semi-circular ring facing the left semi-circular ring is bent towards the center of the circle to form a third protrusion. The third protrusion and the first protrusion are symmetrically arranged with respect to the center of the circle, and the length of the third protrusion is equal to the length of the first protrusion. The length of the first protrusion is greater than the length of the second protrusion. By adopting the above antisymmetric chiral metasurface and its applications and verification methods for phase and amplitude regulation, by breaking the C2 (second-order rotation) symmetry and mirror symmetry, not only can spin-decoupled phase control be achieved through chiral phases, but also the amplitude of the reflected wave can be adjusted using circular dichroism.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano optical technologies, and in particular to an anti-symmetric chiral metasurface and applications and verification methods for phase and amplitude regulation. Background Art

[0002] Chirality is a phenomenon that exists ubiquitously in nature. The chirality of a substance refers to a geometric feature of the substance structure, that is, it cannot be superimposed on its mirror image through translation and in-plane rotation operations.

[0003] At the same time, the polarization state characterizes the electric field oscillation of light in a plane perpendicular to the propagation direction. In circularly polarized light, the electric field vector can be decomposed into two linearly polarized components. The two perpendicular electric field vectors oscillate with a 90° phase shift and propagate along a helical trajectory in the clockwise or counterclockwise direction. Due to the different helical trajectories of the electric field vectors, circularly polarized light can be divided into left-handed circularly polarized light (LCP) and right-handed circularly polarized light (RCP).

[0004] Chiral media exhibit unique optical responses to LCP and RCP. However, the interaction between natural chiral substances and chiral light fields is very weak. In order to perform efficient chiral light field regulation and develop it into optical devices, the academic community has proposed and studied artificially designed chiral metamaterials. In recent years, a two-dimensional version has been developed, which is called a chiral metasurface. It can achieve magneto-electric resonance coupling and be excited with strong chiral optical responses such as optical activity and circular dichroism, and is thus used in technical fields such as biochemical substance detection and circularly polarized optical display.

[0005] From the perspective of light field regulation, chiral metasurfaces are one of the important ways to independently control orthogonal circularly polarized electromagnetic waves. Exploring the electromagnetic theory for spin-decoupled manipulation of LCP and RCP wave components and developing corresponding metasurface devices have become one of the research hotspots in the academic community.

[0006] In the early stage, the almost only method for independent phase control of circularly polarized electromagnetic waves was the Pancharatnam-Berry (PB) phase, that is, when the unit structure rotates by an angle , an additional phase conjugate to LCP and RCP is introduced in the cross-polarized components of its reflection or transmission. Due to the fixed conjugate change of the geometric phase response to LCP and RCP, this greatly limits the spin decoupling function of the metasurface.

[0007] In 2015, Professor Arbabi published in the " Dielectric metasurfaces for complete control of phase and polarization with subwavelength spatial resolution and high transmissionIt is disclosed in "

[0008] In recent years, the chiral phase induced by azimuthal rotation and structural parameter adjustment of chiral meta-atoms has become a new method for the design of spin-decoupled metasurfaces. In 2020, Yuan et al. reported in " Independent phase modulation for quadruplex polarization channels enabled by chirality-assisted geometric- phase metasurfaces " that the chiral-induced phase was introduced by the relative azimuthal difference of multilayer metal resonators, and a four-channel circularly polarized wavefront design was completed by combining the resonant phase; in 2021, Chen et al. reported in " Metasurfaces with Planar Chiral Meta-Atoms for Spin Light Manipulation " that a fully dielectric meta-atom with C2 symmetry was used to control spin waves by combining its geometric phase; in the same year, Song et al. reported in " Spin-Selective Full-Dimensional Manipulation of Optical Waves with Chiral Mirror " the topological phase induced by singular points in non-Hermitian chiral meta-atoms, and spin-decoupled wavefront control was achieved by combining the P-B phase.

[0009] However, the above methods for controlling circularly polarized electromagnetic waves based on non-chiral or chiral meta-atoms still have room for improvement in terms of theoretical complexity, design difficulty, computational cost, etc. Moreover, the combination of the resonant phase or chiral phase with the P-B phase requires more theoretical descriptions, and the analysis of the polarization space needs to be considered while exploring the parameter space. In addition, it is also very difficult to control the amplitude difference of wave components. SUMMARY OF THE INVENTION

[0010] The object of the present invention is to provide an anti-symmetric chiral metasurface and an application and verification method for phase and amplitude regulation to solve the above technical problems.

[0011] To achieve the above object, the present invention provides an anti-symmetric chiral metasurface, which includes a surface layer, an intermediate layer, and a backplane layer arranged in sequence from top to bottom. The surface layer is composed of a left semi-circular ring and a right semi-circular ring. Both ends of the left semi-circular ring facing the right semi-circular ring are bent towards the center of the circle to form a first protrusion and a second protrusion. One end of the right semi-circular ring facing the left semi-circular ring is bent towards the center of the circle to form a third protrusion. The third protrusion is symmetrically arranged with the first protrusion about the center of the circle, and the length of the third protrusion is equal to the length of the first protrusion. The length of the first protrusion is greater than the length of the second protrusion.

[0012] Preferably, the distance between the left semi-circular ring and the right semi-circular ring ;

[0013] The widths of the left semi-circular ring, the right semi-circular ring, the first protrusion, the second protrusion, and the third protrusion ;

[0014] The lengths of the first protrusion and the third protrusion , and the length of the second protrusion .

[0015] Preferably, the material of the middle layer is polyimide, with a dielectric constant , and a loss tangent , and a thickness .

[0016] Preferably, the material of the backplane layer is gold, with a thickness .

[0017] Preferably, the absorption rate of the chiral metasurface to left-handed circularly polarized light is 94.467%, and the absorption rate to right-handed circularly polarized light is 5.659%.

[0018] An application of an antisymmetric chiral metasurface in phase-amplitude modulation, which uses chiral phase and circular dichroism to jointly modulate the phase and amplitude of the reflected circularly polarized wave components.

[0019] A verification method for an application of an antisymmetric chiral metasurface in phase-amplitude modulation, including the following steps:

[0020] S1. Establish a simulation model: Determine the geometric parameters of the chiral metasurface, and then use electromagnetic simulation software to establish a three-dimensional model of the chiral metasurface, define the incident wave as left-handed circularly polarized light or right-handed circularly polarized light, and set the working frequency and boundary conditions at the same time, where the working frequency is in the terahertz band;

[0021] S2. Use electromagnetic simulation software to scan the first protrusion, the second protrusion, and the third protrusion of the chiral metasurface to obtain chiral metasurface simulation units under multiple parameter configurations;

[0022] S3. Simulation analysis: Calculate the reflection amplitude and phase of the chiral metasurface simulation unit under each parameter configuration, and based on the calculated reflection amplitude and phase, select the chiral metasurface simulation unit that meets the expectations as the final structure of the chiral metasurface;

[0023] S4. Conduct functional verification based on the final structure of the chiral metasurface in a selective polarization scenario.

[0024] Preferably, in step S1, the boundary conditions in the x and y directions are set to unit cell, the boundary condition in the z direction is set to open, and the maximum value of the electromagnetic simulation space and the minimum value of the electromagnetic simulation space are both set to 2 for the number of polarization modes;

[0025] In step S2, the first protrusion, the second protrusion, and the third protrusion are scanned from 0 um to 160 um with a step size of 2 um.

[0026] Preferably, in step S3, the calculation formula for the reflection amplitude is as follows:

[0027] (1);

[0028] In the formula, represents the reflection amplitude; represents the reflection coefficient matrix of the circularly polarized wave; and represent the reflection coefficients of the left-handed circularly polarized light and the right-handed circularly polarized light, respectively; and represent the cross reflection coefficients from left-handed circular polarization to right-handed circular polarization and from right-handed circular polarization to left-handed circular polarization, respectively; , , and all represent the elements of the reflection coefficient matrix of the linearly polarized wave; represents the imaginary unit;

[0029] The phase calculation formula is as follows:

[0030] (2);

[0031] In the formula, and represent the phases of the left-handed circularly polarized light and the right-handed circularly polarized light, respectively, varies linearly along direction, remains unchanged; represents the linear phase gradient; represents the initial phase.

[0032] Preferably, step S4 specifically includes the following steps:

[0033] S41. Set the deflection angle of the left-handed circularly polarized light to 30°, and in the parameter space, select four meta-atoms such that forms a linear phase gradient at intervals of 90°, and keep unchanged to obtain a chiral metasurface with spin-selective deflection;

[0034] S42. Simulate the far - field reflection patterns of the chiral metasurface with spin - selective deflection under the incidence of left - handed circularly polarized light and right - handed circularly polarized light, and obtain the modulation effects of the chiral metasurface on left - handed circularly polarized light and right - handed circularly polarized light;

[0035] S43. When left - handed circularly polarized light is incident, substitute the parameters of the final structure of the determined chiral metasurface into the following formula to calculate the reflection angle of left - handed circularly polarized light :

[0036] (3);

[0037] In the formula, represents the spatial wavelength; represents the spatial period;

[0038] S44. Compare and verify the reflection angle of left - handed circularly polarized light calculated by formula (3) with the result obtained from the reflection far - field pattern described in step S42 to confirm whether the final structure of the chiral metasurface has achieved the predetermined goal.

[0039] Therefore, the present invention adopts the above - mentioned anti - symmetric chiral metasurface and the application and verification methods of phase - amplitude modulation, and the beneficial effects are as follows:

[0040] 1. High - selectivity absorption rate: The chiral metasurface shows significantly different absorption characteristics for left - handed circularly polarized light (LCP) and right - handed circularly polarized light (RCP). The absorption rate for LCP is 94.467%, while the absorption rate for RCP is only 5.659%. This high - selectivity absorption makes the chiral metasurface have potential applications in optical filters, sensors, and other photonic devices;

[0041] 2. Geometric design optimization: The surface layer is composed of left - hand semi - rings and right - hand semi - rings, and the best chiral effect is achieved through the specific geometric design of the first protrusion, the second protrusion, and the third protrusion. These geometric parameters (such as length, width, and distance) are optimized to ensure the best performance. The optimization of geometric parameters not only improves the chiral effect but also enhances the selectivity and control ability for light with different polarization states;

[0042] 3. Material selection and performance: The intermediate layer uses polyimide material, which has a low dielectric constant and loss tangent, and an appropriate thickness, helping to reduce energy loss and improve the electromagnetic wave transmission efficiency;

[0043] The backplane layer uses gold material, ensuring good conductivity and reflection performance, and further enhancing the overall performance of the metasurface;

[0044] 4. Simulation verification: Through the comparison and verification of actual simulation and theoretical formula, it is confirmed that the final structure of the chiral metasurface has achieved the predetermined goal, ensuring the effectiveness and reliability of the design;

[0045] 5. Joint control of phase and amplitude: By using chiral phase and circular dichroism, the phase and amplitude of the reflected circularly polarized wave component of the chiral metasurface can be jointly controlled, which provides the possibility for the development of new optical devices, such as spin-selective optical elements for communication, sensing, imaging and other fields.

[0046] In summary, the present invention can selectively absorb one circularly polarized wave (such as LCP) efficiently under specific conditions, while maintaining a high reflectivity for another circularly polarized wave (such as RCP), thereby achieving more flexible and diverse electromagnetic wave manipulation functions, making it excellent in selective absorption, phase and amplitude regulation, and suitable for a variety of optical applications, especially in terahertz band applications. It has great potential.

[0047] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a surface structure diagram of an antisymmetric chiral metasurface of the present invention.

[0049] Figure 2 The reflection far-field pattern of the antisymmetric chiral metasurface in the simulation experiment, where (a) is the spin-dependent reflection amplitude manipulation pattern based on circular dichroism; (b) is the spin-dependent phase manipulation pattern based on circular dichroism; (c) is the spin-dependent reflection amplitude manipulation pattern based on the chiral phase; (d) is the spin-dependent phase manipulation pattern based on the chiral phase; (e) is the electric field distribution of the 0.58THz metaatom when LCP wave (left-handed polarized light) is incident; (f) is the electric field distribution of the 0.58THz metaatom when RCP wave (right-handed polarized light) is incident;

[0050] Figure 3 This is the functional verification result diagram of the simulation experiment; (a) (b) Variation diagram of chiral metasurface structural parameters; (c) The variation of chiral metasurface structural parameters; (d) Variation diagram of chiral metasurface structural parameters; (e) is the reflection far-field pattern of the chiral metasurface under the incidence of LCP wave; (f) is the reflection far-field pattern of the chiral metasurface under the incidence of RCP wave.

[0051] Reference numerals

[0052] 1. Left semi-circular ring; 2. First protrusion; 3. Second protrusion; 4. Right semi-circular ring; 5. Third protrusion. Detailed implementation manner

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the following further details the embodiments of the present invention in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention, and are not used to limit the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of this application. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end.

[0054] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0055] The following details the implementation manner of the present invention in conjunction with the drawings.

[0056] Conventional double-open-loop resonators have mirror symmetry and can accumulate geometric phases or resonance phases of linear polarization in the paths of the polarization space or parameter space, but do not have chiral responses. When the structure is sheared to break the mirror symmetry and second-order rotational symmetry, significant chiral phases and circular dichroism may simultaneously appear, thereby controlling the phases and amplitudes of the reflected waves.

[0057] Based on the above analysis, the present invention is designed as follows: As Figure 1 shown, an anti-symmetric chiral metasurface includes a surface layer, an intermediate layer and a backplane layer arranged in sequence from top to bottom. The surface layer is composed of a left semi-circular ring 1 and a right semi-circular ring 4. Both ends of the side of the left semi-circular ring 1 facing the right semi-circular ring 4 are bent towards the center of the circle to form a first protrusion 2 and a second protrusion 3. One end of the side of the right semi-circular ring 4 facing the left semi-circular ring 1 is bent towards the center of the circle to form a third protrusion 5. The third protrusion 5 and the first protrusion 2 are symmetrically arranged about the center of the circle, and the length of the third protrusion 5 is equal to the length of the first protrusion 2, and the length of the first protrusion 2 is greater than the length of the second protrusion 3.

[0058] The distance between the left semi-circular ring 1 and the right semi-circular ring 4 ; the widths of the left semi-circular ring 1, the right semi-circular ring 4, the first protrusion 2, the second protrusion 3 and the third protrusion 5 ; the lengths of the first protrusion 2 and the third protrusion 5 , the length of the second protrusion 3 .

[0059] The material of the intermediate layer is polyimide, the dielectric constant , the tangent of the loss angle , the thickness .

[0060] The material of the backplane layer is gold, the thickness .

[0061] The absorption rate of the chiral metasurface to left-handed circularly polarized light is 94.467%, and the absorption rate to right-handed circularly polarized light is 5.659%.

[0062] An application of an antisymmetric chiral metasurface in phase-amplitude modulation, which uses chiral phase and circular dichroism to jointly modulate the phase and amplitude of the reflected circularly polarized wave components.

[0063] A verification method for the application of an antisymmetric chiral metasurface in phase-amplitude modulation, including the following steps:

[0064] S1. Establish a simulation model: Determine the geometric parameters of the chiral metasurface, and then use electromagnetic simulation software to establish a three-dimensional model of the chiral metasurface, and define the incident wave as left-handed circularly polarized light or right-handed circularly polarized light, and set the working frequency and boundary conditions at the same time, where the working frequency is in the terahertz band;

[0065] In step S1, the boundary conditions in the x and y directions are set to unit cell (period), the boundary condition in the z direction is set to open, and the maximum value of the electromagnetic simulation space and the minimum value of the electromagnetic simulation space The number of polarization modes are both set to 2;

[0066] S2. Use electromagnetic simulation software to scan the first protrusion, the second protrusion and the third protrusion of the chiral metasurface to obtain the chiral metasurface simulation unit under multiple parameter configurations;

[0067] In step S2, scan the first protrusion, the second protrusion and the third protrusion from 0um to 160um with a step of 2um respectively.

[0068] S3. Simulation analysis: Calculate the reflection amplitude and phase of the chiral metasurface simulation unit under each parameter configuration, and based on the calculated reflection amplitude and phase, select the chiral metasurface simulation unit that meets the expectations as the final structure of the chiral metasurface;

[0069] In step S3, the calculation formula of the reflection amplitude is as follows:

[0070] (1);

[0071] Wherein, represents the reflection amplitude; represents the reflection coefficient matrix of the circularly polarized wave; and respectively represent the reflection coefficients of the left-handed circularly polarized light and the right-handed circularly polarized light; and respectively represent the cross reflection coefficients from left-handed circular polarization to right-handed circular polarization and from right-handed circular polarization to left-handed circular polarization; , , and all represent the elements of the reflection coefficient matrix of the linearly polarized wave; represents the imaginary unit;

[0072] The phase calculation formula is as follows:

[0073] (2);

[0074] Wherein, and respectively represent the phases of the left-handed circularly polarized light and the right-handed circularly polarized light, varies linearly along direction, remains unchanged; represents the linear phase gradient; represents the initial phase.

[0075] S4. The final structure based on the chiral metasurface is functionally verified in the selective polarization scenario.

[0076] Step S4 specifically includes the following steps:

[0077] S41. Set the deflection angle of the left-handed circularly polarized light to 30°, and in the parameter space, select four superatoms such that forms a linear phase gradient at intervals of 90°, and keep unchanged to obtain a chiral metasurface with spin-selective deflection;

[0078] S42. Simulate the reflection far-field patterns of the chiral metasurface with spin-selective deflection under the incidence of left-handed circularly polarized light and right-handed circularly polarized light to obtain the regulation effects of the chiral metasurface on the left-handed circularly polarized light and the right-handed circularly polarized light;

[0079] Simulation conditions: 8×8 chiral metasurfaces are arranged, with the same arrangement structure in each row, one unit changes every two columns, and 4 units are linear phase gradient changes. The operating frequency is set to 0.2THz-0.8 THz. In terms of boundary condition settings, the boundary conditions in the x and y directions are set to periodic (the coordinate axis is periodic), and the boundary condition in the z direction is set to open (open) to calculate the electromagnetic characteristics of the far-field field;

[0080] S43. In the case of left-handed circularly polarized light incident on the chiral metasurface, the parameters of the final structure are substituted into the following formula to calculate the reflection angle of the left-handed circularly polarized light: :

[0081] (3);

[0082] In the formula, represents the spatial wavelength; Represents a spatial period;

[0083] S44. Calculate the reflection angle of left-handed circularly polarized light using formula (3): The result is compared and verified with the result obtained in the reflection far-field pattern described in step S42 to confirm whether the final structure of the chiral metasurface has achieved the predetermined goal.

[0084] Simulation experiment

[0085] Based on the present invention, simulation experiments are carried out and the results are as follows: Figure 2 and Figure 3 As shown by Figure 2 From (a), we can see that , When , it shows obvious circular dichroism, that is, it basically does not reflect LCP waves near the operating frequency, but has a high reflectivity to RCP. Figure 2 From (b), we can see that near the extreme value of circular dichroism A mutation occurs, and the absorption rates of the chiral metasurface for LCP and RCP waves are 94.467% and 5.659% respectively. The chiral metasurface shows a huge absorption of LCP waves near the operating frequency of 0.35THz, and shows effective reflection of RCP waves in the range of 0.3THz-0.4THz. The reflection difference of the two circularly polarized components measured in a specific direction is defined as CD, and the CD value is as high as 0.899 at 0.3536THz. In addition, the chiral metasurface breaks the C2 symmetry, but due to the existence of the chiral phase, it can still be obtained from Figure 2 It is observed in (b) and There are differences.

[0086] Depend on Figure 2As can be seen from (c) and (d), when the co-polarized circularly polarized wave reflected in the frequency range of 0.3 THz to 0.4 THz can be clearly observed. and The reflectivity curves (the reflectivity is equal to the square of the reflection coefficient) are basically coincident. And in the frequency range of 0.3 THz to 0.4 THz, the reflection circular polarization phase of the chiral metasurface and has an obvious phase difference during transmission, and the phase can also be independently regulated. Therefore, is taken.

[0087] From Figure 2 (e), it can be seen that when when the incident light beam is a left-handed circularly polarized light, strong electric fields are generated at the first protrusion and the third protrusion. The incident terahertz wave is excited to have a strong resonance, and the incident electromagnetic wave is converted into ohmic heat. At the same time, the terahertz wave enters the lossy polyimide layer and is trapped inside the medium, and the signal is attenuated and absorbed, causing dielectric loss. The combination of metal loss and dielectric loss leads to the sensitivity of the chiral metasurface to LCP waves. From Figure 2 (f), it can be seen that when the incident light beam is a right-handed circularly polarized light, only a weak electric dipole resonance exists at the port of the right semi-circular ring, and it hardly absorbs RCP. This indicates that the chiral metasurface can achieve efficient selective absorption.

[0088] From Figure 3 (a) and (b), it can be seen that by changing the structural parameter a phase coverage of 2π can be basically achieved, and an approximately angular phase gradient is presented in the parameter space. While only produces a weak phase change of less than π, and it changes approximately linearly in the direction of increase. This indicates that it is possible to achieve differential phase control of the two circular polarization components.

[0089] From Figure 3 (c) and (d), it can be seen that maintains a high amplitude throughout the parameter space, while has a large amplitude change in some regions. Therefore, the phase and amplitude of LCP and RCP can be regulated by adjusting the structural parameters and chirality of the chiral metasurface.

[0090] From Figure 3 (e) and (f), it can be seen that when the RCP wave is incident, the reflected beam hardly deflects. In the case of LCP wave incidence, the phase change interval is 90°, and the spatial size required for one phase period is 4P. At the same time, substituting the structural parameters into formula (3), the reflection angle can be obtained as 29.4°. From Figure 3The reflected angle read in (e) is 30°, and the error is within the acceptable range, thus proving the effectiveness of the present invention.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions of the present invention or make equivalent replacements, and these modifications or equivalent replacements do not enable the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A verification method for the application of an antisymmetric chiral metasurface in phase amplitude control, the antisymmetric chiral metasurface comprising a surface layer, an intermediate layer and a backplane layer arranged in sequence from top to bottom, the surface layer consisting of a left semicircular ring and a right semicircular ring, wherein both ends of the left semicircular ring on a side facing the right semicircular ring are bent toward the center of the circle to form a first protrusion and a second protrusion, and one end of the right semicircular ring on a side facing the left semicircular ring is bent toward the center of the circle to form a third protrusion, the third protrusion is symmetrically arranged with the first protrusion about the center of the circle, and the length of the third protrusion is equal to the length of the first protrusion, and the length of the first protrusion is greater than the length of the second protrusion; the verification method is characterized in that: The following steps are involved: S1. Establishing a simulation model: Determine the geometric parameters of the chiral metasurface, and then use electromagnetic simulation software to establish a three-dimensional model of the chiral metasurface, and define the incident wave as left-handed circularly polarized light or right-handed circularly polarized light, and set the operating frequency and boundary conditions, where the operating frequency is in the terahertz band; S2, using electromagnetic simulation software to scan the first protrusion, the second protrusion, and the third protrusion of the chiral metasurface to obtain a chiral metasurface simulation unit under multiple parameter configurations; S3, simulation analysis: calculate the reflection amplitude and phase of the chiral metasurface simulation unit under each parameter configuration, and select the chiral metasurface simulation unit that meets the expectations based on the calculated reflection amplitude and phase as the final structure of the chiral metasurface; S4. Functional verification of the final structure based on the chiral metasurface under selective polarization scenario; Step S4 specifically includes the following steps: S41, set the deflection angle of left-handed circularly polarized light to 30°; and select four superatoms in the parameter space so that A linear phase gradient is formed at intervals of 90°, and the unchanged, and a chiral metasurface with spin-selective deflection is obtained. and Represent the phases of left-handed circularly polarized light and right-handed circularly polarized light respectively; S42, simulating the reflection far-field pattern of the chiral metasurface with spin-selective deflection under the incidence of left-handed circularly polarized light and right-handed circularly polarized light, and obtaining the control effect of the chiral metasurface on the left-handed circularly polarized light and the right-handed circularly polarized light; S43. In the case of left-handed circularly polarized light incident on the chiral metasurface, the parameters of the final structure are substituted into the following formula to calculate the reflection angle of the left-handed circularly polarized light: : （1）； In the formula, represents the spatial wavelength; Represents a spatial period; S44. Calculate the reflection angle of left-handed circularly polarized light using formula (1): The result is compared and verified with the result obtained in the reflection far-field pattern described in step S42 to confirm whether the final structure of the chiral metasurface has achieved the predetermined goal.

2. The verification method for the application of the antisymmetric chiral metasurface in phase amplitude control according to claim 1 is characterized by: In step S1, the boundary conditions in the x and y directions are set to unit cell, the boundary condition in the z direction is set to open, and the maximum value of the electromagnetic simulation space is and the minimum value of the electromagnetic simulation space The polarization mode numbers are all set to 2; In step S2, the first protrusion, the second protrusion and the third protrusion are scanned respectively from 0 um to 160 um with a step length of 2 um.

3. The verification method for the application of the antisymmetric chiral metasurface in phase amplitude control according to claim 1, characterized in that: In step S3, the calculation formula of the reflection amplitude is as follows: （2）； In the formula, represents the reflection amplitude; Represents the reflection coefficient matrix of circularly polarized waves; and denote the reflection coefficients of left-handed circularly polarized light and right-handed circularly polarized light, respectively; and represent the cross reflection coefficients from left-hand circular polarization to right-hand circular polarization and from right-hand circular polarization to left-hand circular polarization respectively; , , and All represent the reflection coefficient matrix elements of linearly polarized waves; represents an imaginary unit; The phase calculation formula is as follows: （3）； In the formula, along Direction changes linearly, remain unchanged, represents the linear phase gradient; Indicates the initial phase.

4. The verification method for the application of the antisymmetric chiral metasurface in phase amplitude control according to claim 1 is characterized in that: The distance between the left and right semicircles ; Width of the left semicircle, right semicircle, first protrusion, second protrusion, and third protrusion ; Length of the first and third protrusions , the length of the second protrusion .

5. The verification method for the application of the antisymmetric chiral metasurface in phase amplitude control according to claim 1, characterized in that: The material of the middle layer is polyimide, with a dielectric constant of , loss tangent ,thickness .

6. The verification method for the application of the antisymmetric chiral metasurface in phase amplitude control according to claim 1, characterized in that: The backplane layer is made of gold, with a thickness of .

7. The verification method for the application of the antisymmetric chiral metasurface in phase amplitude control according to claim 1, characterized in that: The absorption rate of the chiral metasurface for left-handed circularly polarized light is 94.467%, and the absorption rate for right-handed circularly polarized light is 5.659%.

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