Metasurface structure and method for realizing transverse polarization focusing light splitting

Abstract

The invention provides a metasurface structure and method for realizing transverse polarization focusing light splitting, and the metasurface structure comprises a substrate and a surface structure which is disposed on the substrate. The surface structure is composed of a plurality of sub-wavelength structure units which are arranged in a concentric circular ring mode. The sub-wavelength structure unit performs polarization-independent focusing of an incident beam through transmission phase regulation and control, and performs polarization-dependent light splitting of the incident beam through geometric phase regulation and control. The point diffraction plate can realize light beam splitting and focusing functions related to polarization, has the advantages of being simple in structure and high in integration level, solves the technical problems that an existing point diffraction plate does not support synchronous phase-shifting interference measurement and the contrast ratio of interference fringes is low, and enables the contrast ratio of the interference fringes of point diffraction interference measurement to be higher, the resolving precision to be higher and the resolving speed to be higher.

Description

Technical Field

[0001] This invention relates to the field of optical device technology, and specifically to a metasurface structure and method for achieving lateral polarization focusing and beam splitting. Background Technology

[0002] With the continuous development of optical technology, metasurface structures, as a novel type of optical element, have shown great application potential in the field of light field manipulation due to their characteristics such as ultrathinness, planarity, and high integration. Metasurface structures are typically composed of subwavelength-scale structural unit arrays, which can achieve precise manipulation of the light field by controlling the phase, amplitude, and polarization state of electromagnetic waves.

[0003] In the field of optical measurement, point diffraction interferometry, as a common-path transverse shearing interferometry technique, has advantages such as simple structure and good vibration resistance, and is widely used in wavefront detection of optical systems. Traditional point diffraction interferometry typically uses a pinhole diffraction plate to generate a reference spherical wave, which interferes with the wavefront under test to form interference fringes. However, since the pinhole size is usually on the order of micrometers, extremely small relative to the entire probe spot, the amount of light energy passing through the pinhole is relatively small, resulting in low contrast of the interference fringes, which is detrimental to subsequent data processing.

[0004] Existing point diffraction interferometry techniques typically employ linear carrier demodulation and phase-shifting methods when solving interference fringes. The former, due to the use of Fourier transform and frequency domain filtering, has lower accuracy than the phase-shifting method and is slower, making it difficult to obtain high-frequency information. The latter usually involves wavelength tuning phase shifting or mechanical phase shifting, which cannot perform dynamic measurements and limits its application range.

[0005] Therefore, there is an urgent need to develop a novel metasurface structure that can simultaneously achieve polarization-independent focusing and polarization-correlated beam splitting, improve interference fringe contrast, support synchronous phase-shifting interferometry, thereby improving solution accuracy and speed, enhancing high-frequency quantity detection capabilities, and providing a new solution for point diffraction interferometry technology.

[0006] Therefore, the existing technology still needs further development. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a metasurface structure and method for achieving transverse polarization focusing and beam splitting, so as to solve the technical problems of existing point diffraction plates not supporting synchronous phase-shifting interferometry and low contrast of interference fringes.

[0008] To achieve the above-mentioned technical objectives, according to a first aspect of the present invention, the present invention provides a metasurface structure for achieving transverse polarization focusing and beam splitting, comprising a substrate and a surface structure disposed on the substrate; The surface structure is composed of multiple subwavelength structural units arranged in concentric rings; The subwavelength structural unit performs polarization-independent focusing of the incident beam through transmission phase modulation, and performs polarization-correlated beam splitting of the incident beam through geometric phase modulation.

[0009] Specifically, the subwavelength structural units within each concentric ring have the same size, shape, and rotation angle.

[0010] Specifically, the transmission phase modulation is achieved by adjusting the size and shape of the subwavelength structural unit, and the phase distribution of the transmission phase satisfies: ; in, This represents the phase value of the incident beam at (x, y) on the metasurface. x, y Indicates the coordinate position on the metasurface. λ Indicates the wavelength of the incident light beam. f Indicates focal length. r This represents the radius of the metasurface structure.

[0011] Specifically, the geometric phase modulation decomposes the incident beam into left-handed circularly polarized light and right-handed circularly polarized light, and focuses the left-handed circularly polarized light and the right-handed circularly polarized light at two separate focal points in space.

[0012] Specifically, the two focal points are symmetrically distributed along the horizontal direction, and their spatial separation distance is determined by the tilt angle of the geometric phase control.

[0013] Specifically, the geometric phase modulation is achieved by adjusting the rotation angle of the subwavelength structural unit, so that the left-handed and right-handed circularly polarized light of the incident beam produce symmetrical tilt phase modulation, and the phase distribution of the geometric phase satisfies the following: ; ; in, This represents the phase value of left-handed circularly polarized light at different positions on the metasurface. denoted by , where represents the phase value of right-handed circularly polarized light at different positions on the metasurface, and x represents the horizontal coordinate of any point on the metasurface. Indicates the tilt angle.

[0014] Specifically, the phase modulation of the transverse polarization focusing beam splitter is obtained by superimposing the transmission phase and the geometric phase, and the output phase distribution of the transverse polarization focusing beam splitter satisfies: ; ; in, This represents the phase value of left-handed circularly polarized light at different positions on the metasurface. This represents the phase value of right-handed circularly polarized light at different positions on the metasurface.

[0015] Specifically, the method of transmission phase modulation achieved by adjusting the size and shape of the subwavelength structural unit includes: The concentric ring arrangement of the surface structure is based on the phase distribution design of the focusing lens. Subwavelength structural units of different sizes and shapes on each concentric ring form a subwavelength structural cluster, which can achieve wavefront phase modulation in the range of 0~2π.

[0016] Specifically, the geometric phase modulation is achieved by adjusting the rotation angle of the subwavelength structural unit, and includes the following methods: Based on the principle that geometric phase modulation of left- and right-hand circularly polarized light is opposite, by changing the rotation angle of the subwavelength structural unit on each concentric ring, left-hand circularly polarized light is made to be emitted at an angle along the first direction, while right-hand circularly polarized light is made to be emitted at an angle along the second direction opposite to the first direction.

[0017] According to a second aspect of the present invention, a method for achieving transverse polarization focusing and beam splitting is provided, comprising: S100: The incident beam is incident on a transversely polarized focusing and splitting metasurface structure, and polarization-independent focusing is achieved through transmission phase modulation; S200, simultaneously decomposes the incident beam into left-hand circularly polarized light and right-hand circularly polarized light through geometric phase modulation; S300, left-handed circularly polarized light, and right-handed circularly polarized light are focused at two separate positions in space, forming a transverse shearing interference optical path.

[0018] Beneficial effects: This invention provides a metasurface structure and method for achieving transverse polarization focusing and beam splitting. It achieves polarization-independent focusing of the beam through the transmission phase of the subwavelength structure, while simultaneously achieving polarization-dependent beam splitting through the geometric phase. The transmission phase is achieved by adjusting the size and shape of the subwavelength structure, and the geometric phase is achieved by adjusting the rotation angle of the subwavelength structure. This invention achieves transverse polarization focusing and beam splitting of incident beam-polarized light. Its focusing effect improves the contrast of the interference pattern fringes in point diffraction, thereby improving the calculation accuracy. Its polarization beam splitting effect can introduce polarization phase shifting to improve calculation speed, accuracy, and high-frequency detection capabilities. It solves the problems of existing point diffraction plates not supporting synchronous phase-shifting interferometry and having low fringe contrast, resulting in point diffraction interferometry technology with higher fringe contrast, higher calculation accuracy, and faster calculation speed. Attached Figure Description

[0019] Figure 1This is a schematic diagram of the point diffraction interferometry measurement principle provided in a specific embodiment of the present invention; Figure 2 This is a diagram of a metasurface structure for achieving transverse polarization focusing and beam splitting provided in a specific embodiment of the present invention; Figure 3 This is a schematic diagram of the transmission phase focusing principle provided in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the geometric phase beam splitting principle provided in a specific embodiment of the present invention; Figure 5 This is a diagram illustrating the lateral polarization focusing and beam splitting effect provided in a specific embodiment of the present invention; Figure 6 This is a flowchart of a method for achieving transverse polarization focusing and beam splitting provided in a specific embodiment of the present invention; The reference numerals in the above figures are as follows: 1. Substrate; 2. Surface structure; 3. Subwavelength structural unit; 4. Left-handed circularly polarized light; 5. Right-handed circularly polarized light; 6. Incident beam; 7. Metasurface structure for laterally polarized focusing and beam splitting; 8. Focusing lens; 9. Point diffraction plate; 10. Pinhole; 11. Camera. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings; therefore, the directional terms used are for illustrative purposes and not for limiting the invention.

[0021] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0022] Example 1 Please see Figure 2 This embodiment provides a metasurface structure 7 for achieving transverse polarization focusing and beam splitting, comprising a substrate 1 and a surface structure 2, wherein the surface structure 2 is disposed on the substrate 1. The surface structure 2 is composed of multiple subwavelength structural units 3 arranged in concentric rings. The subwavelength structural units 3 within each concentric ring have the same size, shape, and rotation angle.

[0023] Preferably, the subwavelength structural unit 3 in this embodiment is a subwavelength-scale nanostructure, including one of nanopillars, nanopores, or nanofin structures.

[0024] See Figure 3In this embodiment, the subwavelength structure unit 3 performs polarization-independent focusing of the incident beam 6 through transmission phase modulation, and simultaneously performs polarization-correlated beam splitting of the incident beam 6 through geometric phase modulation. Transmission phase modulation is achieved by adjusting the size and shape of the subwavelength structure unit 3. By placing subwavelength structures of a certain size and shape along the radial direction in each concentric ring, the phase distribution of the entire metasurface can be equivalent to that of a focusing lens 8. Specifically, the phase distribution of the transmission phase can be described as follows: ; in, Let λ represent the phase value of the incident beam 6 at the metasurface (x, y), where x and y represent the coordinate positions on the metasurface, and λ represents the wavelength of the incident beam 6. Indicates focal length. The radius represents the metasurface structure. The above formula describes how to control the transmission phase by adjusting the size and shape of the subwavelength structural unit 3, thereby simulating the effect of a focusing lens 8 with a specific phase distribution. Specifically, it ensures that light waves at different positions on the metasurface structure can propagate according to an ideal phase distribution, thus ultimately achieving the focusing function.

[0025] It is understood that the concentric ring arrangement of the surface structure 2 in this embodiment is based on the phase distribution design of the focusing lens 8. Subwavelength structural units 3 of different sizes and shapes on each concentric ring form a subwavelength structure cluster, which can achieve wavefront phase modulation within the range of 0~2π. Since subwavelength structures of different sizes and shapes modulate the wavefront phase differently, a subwavelength structure cluster composed of several subwavelength structures of different sizes and shapes can be designed based on this principle to meet the wavefront phase modulation within the range of 0~2π. Then, according to the phase distribution of the focusing lens 8, the subwavelength structures in the above subwavelength structure cluster are arranged at the corresponding phase points, thus realizing the design of a focusing superlens based on the transmission phase.

[0026] See Figure 4 In this embodiment, geometric phase modulation decomposes the incident beam 6 into left-handed circularly polarized light 4 and right-handed circularly polarized light 5, and focuses the left-handed circularly polarized light 4 and right-handed circularly polarized light 5 onto two separate focal points in space. These two focal points are symmetrically distributed along the horizontal direction, and their spatial separation distance is determined by the tilt angle α of the geometric phase modulation.

[0027] Further, see Figure 4Geometric phase modulation is achieved by adjusting the rotation angle of the subwavelength structural unit 3, causing symmetrical tilt phase modulation of the left-hand circularly polarized light 4 and the right-hand circularly polarized light 5 of the incident beam 6. Based on the principle that geometric phase modulation of the left-hand circularly polarized light 4 and the right-hand circularly polarized light 5 is opposite, by rotating the subwavelength structural angle on each ring to introduce a tilt in a certain direction for the left-hand circularly polarized light 4 (or the right-hand circularly polarized light 5), a tilt in the opposite direction can be introduced for the right-hand circularly polarized light 5 (or the left-hand circularly polarized light 4). This achieves transverse polarization focusing and beam splitting of the incident linearly polarized light. The phase distributions of the geometric phases of the left-hand circularly polarized light 4 and the right-hand circularly polarized light 5 satisfy the following conditions: ; ; in, This represents the phase value of the left-handed circularly polarized light 4 at different positions on the metasurface. This represents the phase value of right-handed circularly polarized light 5 at different positions on the metasurface. This represents the horizontal coordinates of any point on the hypersurface. The angle represents the tilt angle. The two formulas above describe how to achieve geometric phase control of left-handed circularly polarized light 4 and right-handed circularly polarized light 5 by adjusting the rotation angle of the subwavelength structural unit 3. Specifically, the formulas ensure that left-handed circularly polarized light 4 and right-handed circularly polarized light 5 at different positions on the metasurface can propagate according to the ideal phase distribution, thereby achieving the function of transverse polarization focusing and beam splitting.

[0028] It should be noted that the geometric phase can be controlled by rotating the superatomic structure on each concentric ring by a suitable angle so that the left-hand circularly polarized light 4 (right-hand circularly polarized light 5) in the incident beam 6 is emitted at an angle along a specific direction, and the right-hand circularly polarized light 5 (left-hand circularly polarized light 4) is emitted at an angle along a symmetrical direction.

[0029] It is understood that, based on the principle that the geometric phase modulates the left and right circularly polarized light phases in opposite ways, this embodiment changes the rotation angle of the subwavelength structural unit 3 on each concentric ring, so that the left circularly polarized light 4 is emitted at an angle along the first direction, while the right circularly polarized light 5 is emitted at an angle along the second direction opposite to the first direction.

[0030] Furthermore, in this embodiment, the phase modulation of the transverse polarization focusing beam splitter is obtained by superimposing the transmission phase and the geometric phase, and the output phase distribution of the transverse polarization focusing beam splitter satisfies: ; ; in, This represents the phase value of the left-handed circularly polarized light 4 at different positions on the metasurface. This represents the phase value of right-handed circularly polarized light 5 at different positions on the metasurface.

[0031] See Figure 5 After the incident beam 6 passes through the metasurface structure 7 in this embodiment, which achieves lateral polarization focusing and beam splitting, the final polarization focal length beam splitting effect is as follows: Figure 5 As shown, after the incident beam 6 passes through the transversely polarized focusing and beam splitting metasurface structure 7, its left-hand circularly polarized light 4 and right-hand circularly polarized light 5 are focused at two points in the x-direction, respectively. The focusing effect can improve the contrast of the interference image fringes of the point diffraction, thereby improving the solution accuracy. Its polarization beam splitting effect can introduce polarization phase shift to improve the solution speed, accuracy, and high-frequency quantity detection capability.

[0032] It should be noted that this embodiment provides a metasurface structure for achieving transverse polarization focusing and beam splitting. This metasurface structure achieves polarization-independent focusing and polarization-dependent beam splitting of the incident beam through the synergistic effect of transmission phase and geometric phase. When the beam is incident on the metasurface structure, light of different polarization states is decomposed into left-handed and right-handed circularly polarized light, which are then focused onto two symmetrically distributed focal points in the horizontal direction, thereby achieving the function of transverse polarization focusing and beam splitting. This structure can be widely used in optical imaging, optical communication, optical information processing, and other fields.

[0033] Example 2 Please see Figure 6 This embodiment provides a method for achieving lateral polarization focusing and beam splitting, using the metasurface structure 7 for achieving lateral polarization focusing and beam splitting described in Embodiment 1. The method includes the following steps: S100, the incident beam 6 is incident on the metasurface structure 7 of the transverse polarization focusing beam, and polarization-independent focusing is achieved through transmission phase modulation.

[0034] Specifically, transmission phase modulation is achieved by adjusting the size and shape of the subwavelength structural unit 3. By placing subwavelength structures of a certain size and shape along the radial direction in each concentric ring, the phase distribution of the entire metasurface can be equivalent to a focusing lens 8. The specific phase distribution of the transmission phase can be described as follows: ; in, Let λ represent the phase value of the incident beam 6 at the metasurface (x, y), where x and y represent the coordinate positions on the metasurface, and λ represents the wavelength of the incident beam 6. Indicates focal length. The radius represents the metasurface structure 2. The above formula describes how to control the transmission phase by adjusting the size and shape of the subwavelength structural unit 3, thereby simulating the effect of a focusing lens 8 with a specific phase distribution. Specifically, it ensures that light waves at different positions on the metasurface structure 2 can propagate according to an ideal phase distribution, thus ultimately achieving the focusing function.

[0035] In this step, the incident beam 6 illuminates the metasurface structure 2, which consists of a substrate 1 and a surface structure 2. The surface structure 2 is composed of multiple concentric ring-shaped subwavelength structural units 3. These subwavelength structural units 3 achieve transmission phase modulation through their specific size and shape, thereby achieving polarization-independent focusing of the incident beam 6. The transmission phase modulation follows the phase distribution law described in Embodiment 1, ensuring that incident light of different polarization states can be focused. This solves the problem of… Figure 1 The existing point diffraction interferometry method shown realizes phase shift measurement of point diffraction interferometry technology, which greatly improves the contrast of interference fringes.

[0036] like Figure 1 As shown, existing point diffraction interferometry measurement devices typically include optical components such as a focusing lens 8, a point diffraction plate 9, and a camera 11 arranged sequentially along the optical path. A portion of the test beam (the incident beam 6) is incident through a micrometer-sized pinhole 10 to obtain an ideal reference beam. Interference between this reference beam and the test beam yields interference fringes. Solving these fringes yields the phase of the test beam. Common methods for solving interference fringes include linear carrier demodulation and phase-shifting. The former, due to the use of Fourier transform and frequency domain filtering, has lower accuracy and is slower than the phase-shifting method, and it is also less likely to obtain high-frequency quantities. The latter typically involves wavelength-tuned phase shifting or mechanical phase shifting, neither of which allows for dynamic measurement. Furthermore, since the point diffraction pinhole 10 is typically a micrometer-sized aperture, its fringe contrast is usually low, which is detrimental to calculation. In contrast, the transverse polarization focusing beam splitting method in this embodiment concentrates the reference beam energy, and the beam splitting function achieves synchronous phase shifting, further avoiding the shortcomings of traditional time-shifting methods.

[0037] S200, simultaneously through geometric phase modulation, decomposes the incident beam 6 into left-handed circularly polarized light 4 and right-handed circularly polarized light 5.

[0038] In this step, the subwavelength structural unit 3 in the metasurface structure achieves geometric phase modulation through its rotation angle, decomposing the incident beam 6 into left-handed circularly polarized light 4 and right-handed circularly polarized light 5. This geometric phase modulation causes the left-handed circularly polarized light 4 and the right-handed circularly polarized light 5 to produce symmetrical tilted phase modulation, as described in Embodiment 1, the phase of the left-handed circularly polarized light 4 and the right-handed circularly polarized light 5... The cloths respectively satisfy: ; ; in, This represents the phase value of the left-handed circularly polarized light 4 at different positions on the metasurface. This represents the phase value of right-handed circularly polarized light 5 at different positions on the metasurface. This represents the horizontal coordinates of any point on the hypersurface. The angle represents the tilt angle. The two formulas above describe how to achieve geometric phase control of left-handed circularly polarized light 4 and right-handed circularly polarized light 5 by adjusting the rotation angle of the subwavelength structural unit 3. Specifically, the formulas ensure that left-handed and right-handed circularly polarized light 5 at different positions on the metasurface can propagate according to the ideal phase distribution, thereby achieving the function of transverse polarization focusing and beam splitting.

[0039] S300, left-handed circularly polarized light 4, and right-handed circularly polarized light 5 are focused at two separate positions in space, forming a transverse shearing interference optical path.

[0040] Specifically, in this embodiment, the phase modulation of the transverse polarization focusing beam splitter is obtained by superimposing the transmission phase and the geometric phase, and the output phase distribution of the transverse polarization focusing beam splitter satisfies: ; ; in, This represents the phase value of the left-handed circularly polarized light 4 at different positions on the metasurface. This represents the phase value of right-handed circularly polarized light 5 at different positions on the metasurface.

[0041] In this step, after coordinated modulation of the transmission phase and geometric phase, the left-handed circularly polarized light 4 is emitted at an angle along the first direction and focused at a focal point in space, while the right-handed circularly polarized light 5 is emitted at an angle along the second direction opposite to the first direction and focused at another focal point. These two focal points are symmetrically distributed horizontally, and their spatial separation distance is determined by the tilt angle of the geometric phase modulation. This spatially separated focal point forms a transverse shearing interference optical path, which can be used for polarization state analysis and measurement.

[0042] It should be noted that this embodiment provides a method for achieving transverse polarization focusing and beam splitting. Through the above steps, this method achieves polarization-independent focusing and polarization-dependent beam splitting of the incident beam, decomposing light of different polarization states and focusing it onto two symmetrically distributed focal points in the horizontal direction. This method can be widely used in optical imaging, optical communication, optical information processing, polarization measurement, and other fields, and is particularly suitable for applications that require simultaneous analysis of beam polarization state and spatial distribution. In addition, this invention can also serve as a transverse shearing device to support synchronous phase shifting.

[0043] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0045] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A metasurface structure implementing transverse polarized focusing spectroscopy, comprising a substrate (1), characterized in that, Further comprising a surface structure (2) disposed on the substrate (1); The surface structure (2) is composed of a plurality of concentric circularly arranged subwavelength structure units (3); The subwavelength structure units (3) realize polarization-independent focusing of the incident light beam (6) through transmission phase control, and realize polarization-dependent light splitting of the incident light beam (6) through geometric phase control.

2. The metasurface structure of claim 1, wherein, The subwavelength structure units (3) in each concentric circle have the same size, shape and rotation angle.

3. The metasurface structure of claim 2, wherein, The transmission phase control is realized by adjusting the size and shape of the subwavelength structure units (3), and the phase distribution of the transmission phase satisfies: ； wherein, denotes a phase value of the incident light beam (6) at the meta-surface (x, y), x, y denotes a coordinate position on the meta-surface, λ denotes a wavelength of the incident light beam (6), f denotes a focal length, r denotes a radius of the meta-surface structure (2).

4. The metasurface structure of claim 3, wherein, The geometric phase control decomposes the incident light beam (6) into left circularly polarized light (4) and right circularly polarized light (5), and focuses the left circularly polarized light (4) and the right circularly polarized light (5) at two separate focal points in space.

5. The metasurface structure of claim 4, wherein, The two focal points are symmetrically distributed along the horizontal direction, and the spatial separation distance is determined by the tilt angle of the geometric phase control.

6. The metasurface structure of claim 4, wherein, The geometric phase control is realized by adjusting the rotation angle of the subwavelength structure units (3), so that the left circularly polarized light (4) and the right circularly polarized light (5) of the incident light beam (6) produce symmetric tilt phase modulation, and the phase distribution of the geometric phase satisfies: ； ； wherein, represents the phase value of left-handed circularly polarized light (4) at different positions of the super surface, represents the phase value of right-handed circularly polarized light (5) at different positions of the super surface, x represents the position coordinate of any point on the super surface in the horizontal direction, represents the tilt angle.

7. The metasurface structure of claim 6, wherein, The phase modulation of the transverse polarization focusing and splitting is obtained by superimposing the transmission phase and the geometric phase, and the output phase distribution of the transverse polarization focusing and splitting satisfies: ； ； wherein, represents the phase value of left-handed circularly polarized light (4) at different positions of the super surface, represents the phase value of right-handed circularly polarized light (5) at different positions of the super surface.

8. The metasurface structure of claim 3, wherein, The method for realizing the transmission phase control by adjusting the size and shape of the subwavelength structure units (3) specifically includes: The concentric circular arrangement of the surface structure (2) is based on the phase distribution design of the focusing lens (8), and the subwavelength structure units (3) of different sizes and shapes on each concentric circle form a subwavelength structure cluster, which can realize the control of the wavefront phase in the range of 0-2π.

9. The metasurface structure of claim 6, wherein, The method for realizing the geometric phase control by adjusting the rotation angle of the subwavelength structure units (3) specifically includes: According to the principle that the geometric phase modulates the phase of left and right circularly polarized light in opposite directions, by changing the rotation angle of the subwavelength structure units (3) on each concentric circle, the left circularly polarized light (4) is tilted to exit along a first direction, while the right circularly polarized light (5) is tilted to exit along a second direction opposite to the first direction.

10. A method of achieving lateral polarization focusing spectroscopy, comprising: The method includes: S100, the incident light beam (6) is incident on the transverse polarization focusing and splitting super surface structure (7), and polarization-independent focusing is realized through transmission phase control; S200, the incident light beam (6) is decomposed into left circularly polarized light (4) and right circularly polarized light (5) through geometric phase control; S300, the left circularly polarized light (4) and the right circularly polarized light (5) are respectively focused at two separate positions in space, forming a transverse shear interference light path.

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