A multifunctional wavefront modulation metasurface based on dual-frequency transmission and a method thereof

Abstract

The present application relates to a kind of multifunctional wavefront regulation super surface based on dual-frequency transmission type and method thereof, multifunctional wavefront regulation super surface includes multiple super surface units, single super surface unit includes: dielectric layer;Bottom layer, set in the lower side of dielectric layer, bottom layer includes lower outer open ring, lower inner open ring, lower inner open ring is located in the inside of lower outer open ring;Top layer, set in the upper side of dielectric layer, top layer includes upper outer open ring, upper inner open ring, upper inner open ring is located in the inside of upper outer open ring;Wherein, the central axis of bottom layer, the central axis of top layer, the vertical center line of dielectric layer overlap, and the opening of lower outer open ring and the opening of upper outer open ring are symmetrically arranged as 180 °, lower inner open ring and upper inner open ring are symmetrically arranged as 180 °, so that different mode OAM beam, beam splitting, focusing lens and abnormal refraction and multiple different functions such as can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metasurface devices, in particular to a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type and a method. BACKGROUND

[0002] In recent years, as a two-dimensional periodic planar material composed of metal or dielectric scatterers with subwavelength scale, metasurfaces have attracted extensive attention due to their strong modulation ability on electromagnetic waves. Compared with traditional optical devices, metasurfaces can change different characteristics of incident light on a single extremely thin layer and exhibit new optical properties. Metasurfaces have the advantages of thinness, easy integration, and flexible control, and have great application potential in the fields of imaging, sensing, and communication.

[0003] Wavefront modulation is one of the core functions of metasurfaces. By adjusting the geometry, size, and arrangement of unit structures, metasurfaces can flexibly modulate the phase, amplitude, polarization, and other parameters of electromagnetic waves, thereby generating a specific wavefront distribution. Currently, metasurface-based wavefront modulation technology has achieved a series of results in beam deflection, focusing, and vortex beam generation.

[0004] However, existing metasurfaces, such as the all-dielectric coded metasurface designed in document [IEEE Access, 2019, 7:45716-45722], select two unit structures with opposite phases (0 and π) to design different coding arrays. When linearly polarized light is incident on the coded metasurface, beam focusing, beam splitting, and diffuse scattering are achieved at 4 GHz. However, the designed metasurface can only achieve multifunctional wavefront modulation at a single frequency, making it difficult to meet the application requirements of multiple frequency bands. Document [Optics Express, 2019, 27(1):34-44] proposes a dual-frequency reflective metasurface that utilizes two phases to achieve multi-mode OAM beams. At 5.2 GHz, the transmission phase is used to achieve a phase coverage of 0-2π by changing the size of the unit structure. When linearly polarized light is incident, an OAM beam with mode +1 is achieved. At 10.5-12 GHz, the geometric phase is used to achieve a phase coverage of 0-2π by rotating the metal patch. When circularly polarized light is incident, an OAM deflection beam with mode +2 is achieved. However, the designed metasurface can only achieve single wavefront modulation function, making it difficult to achieve multifunctional integration and independent control of dual-frequency band functions. SUMMARY

[0005] The present application aims to provide a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type, which has multiple wavefront modulation functions and other characteristics, and has good applicability.

[0006] To achieve the above object, the application adopts the following technical solutions:

[0007] A multifunctional wavefront modulation super surface based on a dual-frequency transmission type, comprising a plurality of super surface units, each of the super surface units comprising: a dielectric layer; a bottom layer arranged on the lower side of the dielectric layer, the bottom layer comprising a lower outer open ring and a lower inner open ring, the lower inner open ring being located on the inner side of the lower outer open ring; and a top layer arranged on the upper side of the dielectric layer, the top layer comprising an upper outer open ring and an upper inner open ring, the upper inner open ring being located on the inner side of the upper outer open ring; wherein the central axis of the bottom layer, the central axis of the top layer and the vertical center line of the dielectric layer overlap, and the openings of the lower outer open ring and the upper outer open ring are arranged in 180° symmetry, and the openings of the lower inner open ring and the upper inner open ring are arranged in 180° symmetry.

[0008] Preferably, the material of the bottom layer and the top layer is copper, and the electrical conductivity is 5.8*10 7 S / m; the outer radius of the lower outer open ring and the upper outer open ring is 0.56-0.58mm, the inner radius is 0.51-0.53mm, and the opening is 0.2-0.22mm; the outer radius of the lower inner open ring and the upper inner open ring is 0.25-0.27mm, the inner radius is 0.2-0.22mm, and the opening is 0.14-0.16mm; the thickness of the lower outer open ring, the upper outer open ring, the lower inner open ring and the upper inner open ring is 0.035-0.037mm.

[0009] Preferably, the material of the dielectric layer is quartz, and the dielectric constant is 3.78; the length and width of the dielectric layer are both 1.19-1.21mm, and the thickness of the dielectric layer is 0.14-0.16mm.

[0010] Preferably, each of the super surface units is arranged in an N*N manner, and N is greater than or equal to 5.

[0011] A multifunctional wavefront modulation method based on a dual-frequency transmission type, characterized in that it comprises a plurality of super surface units, and each of the super surface units forms a super surface M1, a super surface M2 and a super surface M3 through photolithography.

[0012] Preferably, the plurality of super surface units of the super surface M1 are arranged according to the following steps:

[0013] S1, the lower outer open ring and the upper outer open ring are arranged in a period of 4π, the phase difference between adjacent regions is π / 4, and the lower outer open ring and the upper outer open ring are arranged in 180° symmetry;

[0014] S2, the lower inner open ring and the upper inner open ring are arranged according to a period of 2pi, the phase difference of adjacent areas is pi / 4, and the lower inner open ring and the upper inner open ring are arranged in 180° symmetry.

[0015] Preferably, the plurality of metasurface units of the metasurface M2 are arranged according to the following steps:

[0016] S1, the lower outer open ring and the upper outer open ring are arranged along the X axis according to the periodic coding sequence of 0000... or 1111..., arranged along the Y axis according to the periodic coding sequence of 0101..., and the lower outer open ring and the upper outer open ring are arranged in 180° symmetry.

[0017] S2, the lower inner open ring and the upper inner open ring are arranged along the X axis according to the periodic coding sequence of 0101..., arranged along the Y axis according to the periodic coding sequence of 0000... or 1111..., and the lower inner open ring and the upper inner open ring are arranged in 180° symmetry.

[0018] Preferably, the plurality of metasurface units of the metasurface M3 are arranged according to the following steps:

[0019] S1, the lower outer open ring and the upper outer open ring are arranged along the X axis according to The phases of each position are calculated and arranged, arranged along the Y axis according to the same angle, and the lower outer open ring and the upper outer open ring are arranged in 180° symmetry.

[0020] S2, the lower inner open ring and the upper inner open ring are arranged along the X axis according to 0°, 45°, 90°... 315° in a period, arranged along the Y axis according to the same angle, and the lower inner open ring and the upper inner open ring are arranged in 180° symmetry.

[0021] Preferably, in step S1, (x) is the phase compensation required by the position of each metasurface unit along the X axis, λ is the working wavelength, f is the focal length, and x is the position of the metasurface unit.

[0022] Compared with the prior art, the present application has the beneficial effects that:

[0023] The above-mentioned technical scheme provides a multifunctional wavefront modulation metasurface based on a double-frequency transmission type, the upper and lower surfaces of the dielectric layer are respectively provided with a bottom layer and a top layer, the bottom layer includes a lower outer open ring and a lower inner open ring, the top layer includes an upper outer open ring and an upper inner open ring, the lower outer open ring and the upper outer open ring are arranged in 180° symmetry, the lower inner open ring and the upper inner open ring are arranged in 180° symmetry, and by changing the angles of the lower outer open ring, the lower inner open ring, the upper outer open ring and the upper inner open ring, different modes of OAM beams, beam splitting, focusing lenses and anomalous refraction and other different functions can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A structure schematic diagram of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0025] Figure 2 A structure schematic diagram of a bottom layer and a top layer of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0026] Figure 3 A schematic diagram of electric field distribution, transmission coefficient and phase of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0027] Figure 4 A phase distribution schematic diagram of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0028] Figure 5 A microscopic schematic diagram of a metasurface unit of a metasurface M1 of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0029] Figure 6 A phase schematic diagram of RCP waves and LCP waves of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type incident along the +z direction is provided for an embodiment of the present application.

[0030] Figure 7 A phase schematic diagram of RCP waves and LCP waves of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type incident along the -z direction is provided for an embodiment of the present application.

[0031] Figure 8 An encoding schematic diagram of a metasurface M2 of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0032] Figure 9 A far-field scattering diagram of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0033] Figure 10 A partial correlation information schematic diagram of a metasurface M3 of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0034] Figure 11 Another partial correlation information schematic diagram of a metasurface M3 of a multifunctional wavefront modulation metasurface based on a dual-frequency transmission type is provided for an embodiment of the present application.

[0035] Figure 12 A magnified schematic diagram of (a). Figure 10

[0036] ​1, medium layer; 2, bottom layer; 21, lower outer open ring; 22, lower inner open ring; 3, top layer; 31, upper outer open ring; 32, upper inner open ring. DETAILED DESCRIPTION

[0037] The application will be described in more detail below with reference to the drawings, it should be noted that the description of the application below with reference to the drawings is only illustrative and not restrictive. Various different embodiments can be combined with each other to form other embodiments not shown in the following description.

[0038] Please refer to Figures 1-2 The application provides a multifunctional wavefront control metasurface based on a dual-frequency transmission type, which comprises a medium layer 1, a bottom layer 2 and a top layer 3.

[0039] The bottom layer 2 is arranged on the lower side of the medium layer 1, the bottom layer 2 comprises a lower outer open ring 21 and a lower inner open ring 22, and the lower inner open ring 22 is located on the inner side of the lower outer open ring 21; the top layer 3 is arranged on the upper side of the medium layer 1, the top layer 3 comprises an upper outer open ring 31 and an upper inner open ring 32, and the upper inner open ring 32 is located on the inner side of the upper outer open ring 31; wherein the central axis of the bottom layer 2, the central axis of the top layer 3 and the vertical center line of the medium layer 1 are overlapped, and the openings of the lower outer open ring 21 and the upper outer open ring 31 are arranged in 180° symmetry, and the openings of the lower inner open ring 22 and the upper inner open ring 32 are arranged in 180° symmetry.

[0040] Specifically, the material of the bottom layer 2 and the top layer 3 is copper, and the electrical conductivity is 5.8x10 7 S / m; the outer radius of the lower outer open ring 21 and the upper outer open ring 31 is 0.56-0.58mm, the inner radius is 0.51-0.53mm, and the opening is 0.2-0.22mm; the outer radius of the lower inner open ring 22 and the upper inner open ring 32 is 0.25-0.27mm, the inner radius is 0.2-0.22mm, and the opening is 0.14-0.16mm; the thickness of the lower outer open ring 21, the upper outer open ring 31, the lower inner open ring 22 and the upper inner open ring 32 is 0.035-0.037mm.

[0041] The material of the medium layer 1 is quartz, the dielectric constant is 3.78, the length and width of the medium layer 1 are both 1.19-1.21mm, and the thickness of the medium layer 1 is 0.14-0.16mm.

[0042] More specifically, the outer radius of the lower outer split ring 21 is 0.56 mm, the inner radius is 0.51 mm, and the split size is 0.2 mm, the outer radius of the lower inner split ring 22 is 0.25 mm, the inner radius is 0.2 mm, and the split size is 0.14 mm, and the thickness is 0.035 mm. The outer radius of the upper outer split ring 31 is 0.56 mm, the inner radius is 0.51 mm, and the split size is 0.2 mm, the outer radius of the upper inner split ring 32 is 0.25 mm, the inner radius is 0.2 mm, the split size is 0.14 mm, and the thickness is 0.035 mm.

[0043] The length and width of the medium layer 1 are both 1.19 mm, and the thickness is 0.14 mm.

[0044] It is conceivable that the metasurface unit is a basic component unit of the multifunctional wavefront modulation metasurface based on a dual-frequency transmission type. Specifically, each metasurface unit is arranged in an N x N manner, N is greater than or equal to 5, and the final shape of the multifunctional wavefront modulation metasurface can be adjusted accordingly according to actual needs.

[0045] Referring to Figure 3 , Figure 3 including Figure 3 (a), Figure 3 (b), Figure 3 (c), Figure 3 (d) four figures, wherein Figure 3 (a) is the electric field distribution of the metasurface unit at 52.5 GHz; Figure 3 (b) is the transmission coefficient phase at 140 GHz when the outer split ring is rotated; Figure 3 (c) is the electric field distribution of the unit structure at 140 GHz; Figure 3 (d) is the transmission coefficient and phase at 52.5 GHz when the inner split ring is rotated.

[0046] From Figure 3 (a), it can be seen that at 52.5 GHz, the electric field is only distributed along the outer split ring. Therefore, Figure 3 (b) shows that when the outer split ring is rotated, the amplitude and phase of the 8 metasurface units at 140 GHz remain basically unchanged, which shows that the rotation of the outer split ring has negligible effect on the transmission amplitude and phase at 140 GHz. Similarly, from Figure 3 (c), it can be seen that at 140 GHz, the electric field is only distributed along the inner split ring. Therefore, Figure 3 (d) shows that when the inner split ring is rotated, the amplitude and phase of the 8 metasurface units at 52.5 GHz fluctuate very little. Therefore, the outer split ring mainly affects the transmission amplitude and phase at 52.5 GHz, and the inner split ring mainly affects the transmission amplitude and phase at 140 GHz.

[0047] Based on this, the application further discloses a multifunctional wavefront regulation method based on a dual-frequency transmission type, comprising a plurality of super surface units, and each super surface unit is formed by photolithography into a super surface M1, a super surface M2 and a super surface M3.

[0048] The plurality of super surface units of the super surface M1 are arranged according to the following steps:

[0049] S1, the lower outer opening ring 21 and the upper outer opening ring 31 are arranged according to a period of 4pi, the phase difference between adjacent regions is pi / 4, and the lower outer opening ring 21 and the upper outer opening ring 31 are arranged in a 180° symmetry.

[0050] S2, the lower inner opening ring 22 and the upper inner opening ring 32 are arranged according to a period of 2pi, the phase difference between adjacent regions is pi / 4, and the lower inner opening ring 22 and the upper inner opening ring 32 are arranged in a 180° symmetry.

[0051] Please refer to Figure 4 , Figure 4 including Figure 4 (a) and Figure 4 (b), wherein Figure 4 (a) is a phase distribution when the OAM mode is +1, Figure 4 (b) is a phase distribution when the OAM mode is +2.

[0052] In step S1, the lower outer opening ring 21 and the upper outer opening ring 31 are arranged according to the phase shown in Figure 4 (b), and in step S2, the lower inner opening ring 22 and the upper inner opening ring 32 are arranged according to the phase shown in Figure 4 (a).

[0053] Please refer to Figures 5-7 , Figure 6 including Figure 6 (a), Figure 6 (b), Figure 6 (c), Figure 6 (d), wherein Figure 6 (a) is a phase when a right circularly polarized wave (RCP) along the +z direction is incident on the super surface at 52.5GHz; Figure 6 (b) is a phase when a right circularly polarized wave (RCP) along the +z direction is incident on the super surface at 140GHz; Figure 6 (c) is a phase when a left circularly polarized wave (LCP) along the +z direction is incident on the super surface at 52.5GHz; Figure 6(d) is the phase of the left-handed circularly polarized wave (LCP) at 140 GHz when the super surface is incident along the +z direction.

[0054] Figure 7 comprising Figure 7 (a), Figure 7 (b), Figure 7 (c), Figure 7 (d), wherein Figure 7 (a) is the phase of the right-handed circularly polarized wave (RCP) at 52.5 GHz when the super surface is incident along the -z direction; Figure 7 (b) is the phase of the right-handed circularly polarized wave (RCP) at 140 GHz when the super surface is incident along the -z direction; Figure 7 (c) is the phase of the left-handed circularly polarized wave (LCP) at 52.5 GHz when the super surface is incident along the -z direction; Figure 7 (d) is the phase of the left-handed circularly polarized wave (LCP) at 140 GHz when the super surface is incident along the -z direction.

[0055] Therefore, when the right-handed circularly polarized wave (RCP) is incident to the super surface, the OAM mode of +2 OAM beam is realized at 52.5 GHz, and the OAM mode of +1 OAM is realized at 140 GHz, while when the left-handed circularly polarized wave (LCP) is incident to the super surface, the OAM mode of -2 OAM is realized at 52.5 GHz, and the OAM mode of -1 OAM is realized at 140 GHz.

[0056] The plurality of super surface units of the super surface M2 are arranged according to the following steps:

[0057] S1, the lower outer open ring 21 and the upper outer open ring 31 are arranged along the X axis according to the periodic coding sequence of 0000... or 1111..., arranged along the Y axis according to the periodic coding sequence of 0101..., and the lower outer open ring 21 and the upper outer open ring 31 are arranged in 180° symmetry.

[0058] S2, the lower inner open ring 22 and the upper inner open ring 32 are arranged along the X axis according to the periodic coding sequence of 0101..., arranged along the Y axis according to the periodic coding sequence of 0000... or 1111..., and the lower inner open ring 22 and the upper inner open ring 32 are arranged in 180° symmetry.

[0059] Please refer to Figure 8 , Figure 8 comprising Figure 8 (a), Figure 8 (b), wherein Figure 8 (a) is the arrangement coding schematic diagram along the y axis according to "010101..."; Figure 8 (b) is the arrangement coding schematic diagram along the x axis according to "010101...".

[0060] In step S1, the lower outer open rings 21 and the upper outer open rings 31 are arranged according to the coding sequence shown in Figure 8 (a). In step S2, the lower inner open rings 22 and the upper inner open rings 32 are arranged according to the coding sequence shown in Figure 8 (b).

[0061] Referring to Figure 9 , Figure 9 including Figure 9 (a), Figure 9 (b), wherein Figure 9 (a) is a far-field scattering pattern at 52.5 GHz, Figure 9 (b) is a far-field scattering pattern at 140 GHz.

[0062] Therefore, the metasurface M2 splits the incident right-handed circularly polarized wave (RCP) into two left-handed circularly polarized wave (LCP) beams along the y-axis at 52.5 GHz, and splits the right-handed circularly polarized wave (RCP) into two left-handed circularly polarized wave (LCP) beams along the x-axis at 140 GHz.

[0063] The plurality of metasurface units of the metasurface M3 are arranged according to the following steps:

[0064] S1, the lower outer open rings 21 and the upper outer open rings 31 are arranged according to (x) along the X-axis, and the lower outer open rings 21 and the upper outer open rings 31 are arranged according to the same angle along the Y-axis, and the lower outer open rings 21 and the upper outer open rings 31 are arranged symmetrically at 180°.

[0065] S2, the lower inner open rings 22 and the upper inner open rings 32 are arranged according to 0°, 45°, 90°...315° as a period along the X-axis, and the lower inner open rings 22 and the upper inner open rings 32 are arranged according to the same angle along the Y-axis, and the lower inner open rings 22 and the upper inner open rings 32 are arranged symmetrically at 180°.

[0066] In step S1, (x) is the phase compensation required at each position of the metasurface unit along the X-axis, λ is the working wavelength, f is the focal length, and x is the position of the metasurface unit.

[0067] Referring to Figures 10-12 , Figure 10 including Figure 10 (a), Figure 10 (b), Figure 10 (c), Figure 11 including Figure 11 (a), Figure 11 (b), wherein Figure 10 (a) is a schematic diagram of the arrangement of the metasurface units of the top layer 3; Figure 10 (b) is the electric field density distribution of the xoy plane at 52.5 GHz.Figure 10 (c) is the electric field density distribution in the xoz plane at 52.5GHz; Figure 11 (a) is the far-field scattering pattern at 140GHz; Figure 11 (b) is a normalized refraction amplitude diagram. Figure 12 is Figure 10 (a) is an enlarged diagram.

[0068] This embodiment selects 21 metasurface units in total, arranges the metasurface units in sequence, and arranges the right-handed circularly polarized wave (RCP) along the +z direction to the arranged metasurface, and the effect is as shown in Figure 10 (b), Figure 10 (c), Figure 11 (a), Figure 11 (b) shows. From Figure 10 (b), Figure 10 (c) can be seen that the right-handed circularly polarized wave (RCP) produces a light column after passing through the metasurface, from Figure 11 (a), Figure 11 (b) can be seen that the anomalous refraction is realized at 140GHz, and the angle of beam deflection is 13.2º, and the anomalous deflection angle can be calculated by the formula The theoretical result is 12.9°.

[0069] In summary, the application provides a multifunctional wavefront control metasurface based on a dual-frequency transmission type, which can be used to design a mask plate according to the designed metasurface array, and then use photolithography and other technologies to prepare the designed bottom layer 2 and top layer 3 on both sides of the dielectric layer 1. The multifunctional wavefront control metasurface has the following beneficial effects:

[0070] 1. The multifunctional wavefront control metasurface based on a dual-frequency transmission type can independently control electromagnetic waves at two different frequencies, breaking through the limitation that traditional metasurfaces can usually only work at a single frequency, and expanding the application scenarios.

[0071] 2. The multifunctional wavefront control metasurface based on a dual-frequency transmission type not only can control the wavefront, but also can realize the integration of multiple functions, such as focusing, deflection, vortex beam, etc. This multifunctional integration is realized through a single structure, reducing the complexity and cost of the device.

[0072] 3. The multifunctional wavefront control metasurface based on a dual-frequency transmission type, compared with traditional reflective metasurfaces, adopts a transmission type structure, reduces energy loss, improves efficiency, and is suitable for application systems that require high transmittance.

[0073] The above embodiments are only the preferred embodiments of the present application, and cannot be used to limit the protection scope of the present application, and any non-essential changes and replacements made by those skilled in the art on the basis of the present application shall fall within the protection scope of the present application.

Claims

1. A multifunctional wavefront control metasurface based on dual-frequency transmission, characterized in that: Comprising a plurality of metasurface units, a single metasurface unit comprises: dielectric layer (1); A bottom layer (2) is arranged on the lower side of the dielectric layer (1), the bottom layer (2) comprising a lower outer opening ring (21) and a lower inner opening ring (22), the lower inner opening ring (22) being located on the inner side of the lower outer opening ring (21); A top layer (3) is arranged on the upper side of the dielectric layer (1), the top layer (3) comprising an upper outer opening ring (31) and an upper inner opening ring (32), the upper inner opening ring (32) being located on the inner side of the upper outer opening ring (31); wherein the central axis of the bottom layer (2), the central axis of the top layer (3), and the vertical center line of the dielectric layer (1) overlap, and the opening of the lower outer opening ring (21) and the opening of the upper outer opening ring (31) are arranged 180° symmetrically, and the opening of the lower inner opening ring (22) and the opening of the upper inner opening ring (32) are arranged 180° symmetrically; The outer radius of the lower outer opening ring (21) and the upper outer opening ring (31) is 0.56-0.58 mm, the inner radius is 0.51-0.53 mm, and the opening is 0.2-0.22 mm; The outer radius of the lower inner opening ring (22) and the upper inner opening ring (32) is 0.25-0.27 mm, the inner radius is 0.2-0.22 mm, and the opening is 0.14-0.16 mm; The thickness of the lower outer opening ring (21), the upper outer opening ring (31), the lower inner opening ring (22), and the upper inner opening ring (32) is 0.035-0.037 mm.

2. The dual-frequency transmission-type multifunctional wavefront control metasurface according to claim 1, characterized in that: The bottom layer (2) and the top layer (3) are made of copper, and the electrical conductivity is 5.8×10 7 S / m.

3. The dual-frequency transmission-based multifunctional wavefront control metasurface according to claim 1, characterized in that: The dielectric layer (1) is made of quartz with a dielectric constant of 3.

78. The length and width of the dielectric layer (1) are both 1.19-1.21 mm, and the thickness of the dielectric layer (1) is 0.14-0.16 mm.

4. The dual-frequency transmission-based multifunctional wavefront control metasurface according to claim 1, characterized in that: The metasurface units are arranged in an N×N manner, where N is greater than or equal to 5.

5. A multifunctional wavefront control method based on dual-frequency transmission, characterized in that: The multifunctional wavefront control metasurface based on the dual-frequency transmission type as described in any one of claims 1 to 4 includes a plurality of metasurface units, and each of the metasurface units is formed into a metasurface M1, a metasurface M2, and a metasurface M3 by photolithography.

6. The multifunctional wavefront control method based on dual-frequency transmission type according to claim 5, characterized in that: The multiple supersurface units of the supersurface M1 are arranged according to the following steps: S1, the lower outer open ring (21) and the upper outer open ring (31) are arranged according to a period of 4π, the phase difference between adjacent regions is π / 4, and the lower outer open ring (21) and the upper outer open ring (31) are arranged symmetrically at 180°; S2, the lower inner open ring (22) and the upper inner open ring (32) are arranged according to a period of 2π, the phase difference between adjacent regions is π / 4, and the lower inner open ring (22) and the upper inner open ring (32) are arranged symmetrically at 180°.

7. The multifunctional wavefront control method based on dual-frequency transmission type according to claim 5, characterized in that: The multiple supersurface units of the supersurface M2 are arranged according to the following steps: S1, the lower outer opening ring (21) and the upper outer opening ring (31) are arranged along the X axis according to a periodic coding sequence of 0000... or 1111..., and along the Y axis according to a periodic coding sequence of 0101..., and the lower outer opening ring (21) and the upper outer opening ring (31) are arranged symmetrically at 180 degrees; S2, the lower inner open ring (22) and the upper inner open ring (32) are arranged along the X axis according to a periodic coding sequence of 0101..., and along the Y axis according to a periodic coding sequence of 0000... or 1111..., and the lower inner open ring (22) and the upper inner open ring (32) are arranged symmetrically at 180 degrees.

8. The multifunctional wavefront control method based on dual-frequency transmission type according to claim 5, characterized in that: The multiple supersurface units of the supersurface M3 are arranged according to the following steps: S1, the lower outer opening ring (21) and the upper outer opening ring (31) are arranged along the X axis according to Calculate the phase of each position and arrange them at the same angle along the Y axis, and arrange the lower outer open ring (21) and the upper outer open ring (31) symmetrically at 180 degrees; S2, the lower inner opening ring (22) and the upper inner opening ring (32) are arranged along the X axis in a cycle of 0°, 45°, 90°...315°, and arranged along the Y axis at the same angle, and the lower inner opening ring (22) and the upper inner opening ring (32) are arranged symmetrically at 180°; In step S1, (x) is the phase compensation required at each metasurface unit along the X-axis, λ is the operating wavelength, f is the focal length, and x is the position of the metasurface unit.

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