Polarization-independent chiral-selective reflection and multi-dimensional light field modulation devices and methods

Abstract

This application discloses a polarization-independent chiral selective reflection and multidimensional optical field modulation device and method, relating to the fields of integrated photonics and micro / nano optics. The device includes: a geometrically phased liquid crystal layer, a transparent capping layer, a chiral metasurface array layer, a dielectric substrate layer, and a total reflection layer; wherein, the chiral metasurface array layer can break the in-plane mirror symmetry and exhibit chiral selective reflection characteristics in the target wavelength band. The geometrically phased liquid crystal converts the polarization state of arbitrary incident light into orthogonal left-handed and right-handed circularly polarized light. The chiral metasurface array layer selectively reflects one type of circularly polarized light while absorbing another type of circularly polarized light with the opposite chirality. The reflected circularly polarized light exits through the geometrically phased liquid crystal, achieving two-way phase modulation. This invention achieves geometrically phase modulation by four times the rotation angle of liquid crystal molecules, and has the advantages of compact structure, low crosstalk, low cost, and easy integration with semiconductor processes.

Description

Technical Field

[0001] This application relates to the fields of integrated photonics and micro / nano optics, and in particular to polarization-independent chiral selective reflection and multidimensional optical field manipulation devices and methods. Background Technology

[0002] In recent years, as optoelectronic systems have continued to develop towards miniaturization and integration, there is a need for precise and coordinated control of multiple dimensions of electromagnetic waves, including amplitude, phase, polarization, and wavelength. This has led to significant application demands in fields such as solid-state lidar (LiDAR) and augmented reality / virtual reality (AR / VR) displays. However, traditional wavefront shaping devices, including mechanical beam deflectors and conventional refractive lenses, have gradually become bottlenecks limiting further improvements in optical system performance due to their large size, slow response speed, and difficulty in integrating with other semiconductor devices.

[0003] In recent years, liquid crystal diffraction devices based on geometric phase (Pancharatnam-Berry phase, or PBP) have attracted widespread attention due to their ability to provide continuous spatial phase modulation. However, in order to achieve 0 to 2 To achieve complete phase coverage within the specified range, the optical axis orientation of liquid crystal molecules must undergo a physical rotation from 0° to 180°. This places extremely high demands on processing techniques such as optically controlled alignment, and topological defects, such as misalignment lines, are easily generated locally during processing, leading to increased device scattering loss and a sharp decline in diffraction efficiency. Furthermore, due to their physical limitations, traditional solid-state PB phase liquid crystals lack the ability to selectively absorb and reflect electromagnetic field dimensions, including optical field amplitude, polarization state, and wavelength, resulting in relatively limited functionality.

[0004] On the other hand, optical metasurfaces have achieved remarkable multidimensional optical field manipulation capabilities by designing the geometry and arrangement of nanoantennas at the subwavelength scale. However, single-layer static metasurfaces are typically extremely sensitive to the polarization state of incident light when achieving efficient beam deflection or complex holographic projection. To achieve decoupling of absorption and reflection for specific polarizations such as single circular polarization, existing chiral metasurfaces often require extremely complex designs for multifunctional integration. Furthermore, when faced with arbitrary polarization or unpolarized light incident, theoretical energy losses of up to 50% or more or severe polarization crosstalk are unavoidable.

[0005] To overcome the limitations of single technologies, the industry has attempted to combine liquid crystals with metasurfaces. However, existing cascade solutions primarily rely on complex electro-controlled liquid crystal layers, such as nematic or nonlinear liquid crystals, to dynamically tune the metasurface. This approach not only requires the introduction of transparent electrodes, such as ITO films, leading to additional losses, but also significantly increases the manufacturing cost of the device and the complexity of the driving circuitry. More importantly, existing passive composite structures still fail to overcome the limitation of a single circular polarization response at the physical level, and cannot simultaneously achieve efficient compatibility with arbitrary polarization states, selective absorption and reflection of specific chiralities, and phase multiplication amplification.

[0006] Therefore, there is an urgent need in this field for a polarization-independent optical device that is compact, low-cost, easy to mass-produce, and integrated with semiconductor processes. This device needs to be able to efficiently decouple the polarization of arbitrary incident light, achieving absorption and reflection of circularly polarized light with specific chirality while simultaneously multiplying the geometric phase of the reflected light. This would fundamentally reduce the difficulty of liquid crystal alignment processes and expand the application boundaries of multidimensional light field manipulation. Summary of the Invention

[0007] Therefore, it is necessary to address the technical shortcomings of existing technologies, such as the complexity of liquid crystal alignment processes, the high sensitivity of traditional metasurfaces to incident polarization states, and the high manufacturing cost of composite devices, by providing polarization-independent chiral selective reflection and multidimensional light field manipulation devices and methods. These devices and methods can efficiently decouple incident light of arbitrary polarization states and, while achieving absorption of specific chiral circularly polarized light, utilize physical-level reflection and folding mechanisms to achieve 4-fold phase modulation, thereby significantly reducing the manufacturing difficulty of the devices and improving the flexibility of multidimensional light field manipulation.

[0008] In a first aspect, this application provides a polarization-independent chiral selective reflection and multidimensional optical field manipulation device, the device being a multilayer stacked structure, comprising, from top to bottom:

[0009] A geometric phase liquid crystal layer is used to provide a spatially continuously varying geometric phase distribution and to convert incident light of arbitrary polarization state into orthogonally circularly polarized light with opposite chirality.

[0010] A transparent overlay is used for structural support and protection, as well as refractive index matching;

[0011] Chiral metasurface arrays, composed of subwavelength nanoantennas, are used to apply asymmetric modulation of absorption or reflection to circularly polarized light with opposite chirality.

[0012] Dielectric substrate layer, used to form optical microcavities;

[0013] Total reflection layer, used to block light beam transmission and create reflection.

[0014] In one embodiment, the geometric phase liquid crystal layer is a passive polymer film with a fixed optical axis orientation, and the optical axis orientation angle of the liquid crystal molecules is distributed in a one-dimensional or two-dimensional gradient in the plane.

[0015] In one embodiment, the subwavelength nanoantenna in the chiral metasurface array layer is any two-dimensional or three-dimensional geometric configuration that satisfies the condition of breaking in-plane mirror symmetry.

[0016] In one embodiment, the subwavelength nanoantenna in the chiral metasurface array layer is a metallic material with plasmon effect.

[0017] In one embodiment, the dielectric substrate layer is a multilayer composite dielectric structure.

[0018] In one embodiment, the thickness of the total reflection layer is greater than the optical skin depth of the target operating wavelength band of the device.

[0019] In one embodiment, the target operating band of the device is the near-infrared band.

[0020] In one embodiment, the device is configured in a system including a beam deflector, a wavefront shaper, and a polarization multiplexer.

[0021] Secondly, this application also provides a method for optical field manipulation, based on the aforementioned polarization-independent chiral selective reflection and multidimensional optical field manipulation device, the method comprising:

[0022] Incident light of arbitrary polarization is modulated and decomposed by a geometric phase liquid crystal layer, outputting circularly polarized light of the first chirality and circularly polarized light of the second chirality;

[0023] The chiral metasurface array layer absorbs circularly polarized light of the first chirality and reflects circularly polarized light of the second chirality;

[0024] The reflected circularly polarized light of the second chirality passes through the geometric phase liquid crystal layer and exits, achieving two-way modulation.

[0025] In one embodiment, the method further includes:

[0026] By changing the geometry and spatial arrangement of the subwavelength nanoantennas in the chiral metasurface array layer, and in coordination with the geometric phase liquid crystal layer, four times geometric phase modulation of the incident light is achieved, while polarization state conversion and wavelength selective response of the outgoing beam are realized, thus completing multidimensional optical field manipulation.

[0027] The aforementioned polarization-independent chiral selective reflection and multidimensional optical field manipulation device and method comprises a reflective multilayer structure, consisting of, from top to bottom: a geometric phase liquid crystal layer, a transparent capping layer, a chiral metasurface array layer, a dielectric substrate layer, and a total reflection layer. The chiral metasurface array layer is composed of subwavelength nanoantennas, which can break the in-plane mirror symmetry and exhibit chiral selective reflection characteristics in the target wavelength band. The geometric phase liquid crystal converts the polarization state of any incident light into left-handed and right-handed circularly polarized light with opposite chirality. Then, the chiral metasurface array selectively reflects one type of circularly polarized light while absorbing the other type with opposite chirality. Simultaneously, due to the two-way phase modulation, this invention achieves geometric phase modulation of four times the liquid crystal molecule rotation angle, offering advantages such as compact structure, low crosstalk, low cost, and easy integration with semiconductor processes. It can be widely applied in beam deflection, polarization multiplexing, AR displays, and highly integrated optical systems for solid-state lidar. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a polarization-independent chiral selective reflection and multidimensional optical field manipulation device in one embodiment.

[0029] Figure 2 This is a functional schematic diagram of a polarization-independent chiral selective reflection and multidimensional optical field manipulation device in one embodiment.

[0030] Figure 3 This is a comparison of the reflectance of left-handed and right-handed circularly polarized light within the target operating wavelength in one embodiment.

[0031] Figure 4 This is a graph showing the polarization conversion efficiency (PCR) versus wavelength when operating with a specific chiral incident light in one embodiment.

[0032] Figure 5 This is a graph showing the geometric phase response of the reflected beam as a function of the nanoantenna rotation angle in one embodiment.

[0033] Figure descriptions: 100, Device body; 10, Geometric phase liquid crystal layer; 20, Transparent capping layer; 30, Chiral metasurface array layer; 41, First dielectric layer; 42, Second dielectric layer; 50, Total reflection layer. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0035] This application provides a polarization-independent chiral selective reflection and multidimensional optical field manipulation device, such as... Figure 1As shown, the device body 100 is a reflective multilayer stacked structure, which includes, from top to bottom: a geometric phase liquid crystal layer 10, a transparent capping layer 20, a chiral metasurface array layer 30, a dielectric substrate layer, and a total reflection layer 50. The chiral metasurface array layer 30, the dielectric substrate layer, and the total reflection layer 50 together constitute a chiral selective absorber and reflector.

[0036] Its working principle is as follows Figure 2 As shown, when incident light of any polarization state is incident on the PB phase liquid crystal layer, the PB phase liquid crystal layer decomposes the incident light into left-handed circularly polarized light (hereinafter referred to as LCP) and right-handed circularly polarized light (hereinafter referred to as RCP), and LCP and RCP carry phases with equal amplitudes but opposite signs. LCP and RCP are incident on the chiral metasurface layer along the +z axis, i.e., the transmission direction. The chiral metasurface layer selectively absorbs the incident LCP and selectively reflects the incident RCP. At this time, since the transmission direction becomes the -z axis direction, i.e., the reverse transmission path, according to the general visual rotation rule, the reflected light becomes LCP. The LCP reflected by the chiral metasurface layer passes through the PB phase liquid crystal layer again along the reverse transmission path. After passing through the PB phase liquid crystal layer, LCP is additionally superimposed with +2. The phase; finally, the incident arbitrary polarized light, after two stages of modulation by the device, is emitted in the form of RCP, and the emitted RCP carries +4 The target modulation phase is to achieve a 4x phase multiplication effect.

[0037] The chiral metasurface array layer 30, by altering the geometry and spatial arrangement of the subwavelength nanoantennas, not only collaborates with the solid-state geometric phase liquid crystal layer 10 to achieve 4D resonance of incident light. Geometric phase modulation also enables polarization state conversion and wavelength-selective response of the outgoing beam, achieving multidimensional optical field control.

[0038] In one embodiment, the geometric phase liquid crystal layer 10 is a passive polymer film with a fixed optical axis orientation, which does not contain driving electrodes and is not electrically adjustable. The optical axis orientation angles of the liquid crystal molecules inside it are distributed in a one-dimensional or two-dimensional gradient in the plane. Since no external driving is required, this layer completely avoids the additional losses and process complexity caused by introducing transparent electrodes such as ITO films.

[0039] In one embodiment, the transparent capping layer 20 is disposed below the geometric phase liquid crystal layer 10, serving not only to provide physical support and protection for the underlying micro / nano structure, but also to play a crucial role in optical refractive index matching. The transparent capping layer 20 is preferably made of silicon dioxide to ensure the uniformity of the liquid crystal molecule arrangement and optical purity.

[0040] In one embodiment, the chiral metasurface array layer 30 is composed of multiple subwavelength nanoantennas arranged periodically and embedded within the transparent capping layer 20. To obtain extremely strong chiral optical response and circular dichroism, the geometry or array arrangement of these subwavelength nanoantennas must satisfy the prerequisite of breaking in-plane mirror symmetry. The chiral metasurface array layer 30 can be implemented in two ways: one is that each wavelength nanoantenna unit is a chiral structure, specifically employing two-dimensional structures such as L-shaped, V-shaped, or Z-shaped structures with unequal-length orthogonal double arms, or three-dimensional structures such as helical columnar structures or double-layer misaligned structures; the other is to use non-chiral wavelength nanoantennas, but arranged in an asymmetric, rotating pattern to form an asymmetric polymer shape, making the entire unit cell chiral. Figure 1 In the device body 100 shown, the subwavelength nanoantenna is an L-shaped structure made of gold material.

[0041] The material for the subwavelength nanoantenna is selected from metallic materials exhibiting plasmon effects. Preferably, the metallic material is selected from gold, silver, aluminum, copper, or alloys thereof.

[0042] In one embodiment, it is disposed below the chiral metasurface array layer 30. To achieve impedance matching and absorption at a specific wavelength, the dielectric substrate layer is designed as a multilayer composite dielectric microcavity structure. Preferably, the dielectric substrate layer includes a first dielectric layer 41 and a second dielectric layer 42 stacked sequentially from top to bottom. More preferably, the first dielectric layer 41 is a silicon nitride layer, and the second dielectric layer 42 is a silicon dioxide layer.

[0043] In one embodiment, the bottom layer of the device is made of a metallic material with a strong surface plasmon resonance effect, such as gold, silver, copper, or aluminum. The thickness of the total reflection layer 50 needs to be set to be much greater than the optical skin depth of the target operating wavelength to ensure that the transmittance approaches zero, thereby reflecting all unabsorbed light beams back to the upper structure. The target operating wavelength of the device is the near-infrared band; preferably, the center operating wavelength is around 1200 nm.

[0044] In one embodiment, the device is configured as a beam deflector, wavefront shaper, or polarization multiplexer, and is applied in solid-state lidar or augmented reality (AR) display systems.

[0045] The two-dimensional planar dimensions of the entire device body 100 can be designed from 1 mm × 1 mm to 100 mm × 100 mm according to application requirements, and the array region contains thousands to tens of millions of metasurface units.

[0046] The physical modulation mechanism and workflow of the device body 100 are as follows:

[0047] The target operating band in this embodiment is the near-infrared band. When incident light containing arbitrary polarization states enters the device body 100 from top to bottom, it first passes through the geometric phase liquid crystal layer 10. This liquid crystal layer is equivalent to a distributed broadband half-wave plate, which decouples the incident light and converts it into left-handed and right-handed circularly polarized light with opposite chirality, and assigns corresponding initial geometric phases to these two beams of light according to the orientation angle of the local liquid crystal molecules. The modulation process of incident light with arbitrary polarization states by this device can be completely and rigorously quantitatively described by the Jones vector orthogonal decomposition of polarization states and the Jones matrix transmission model, as follows:

[0048] For incident light of any polarization state, its electric field vector can be decomposed under a complete orthogonal basis composed of LCP and RCP, and the corresponding Jones vector expression is:

[0049]

[0050] In the formula, Represents the RCP component. Indicates LCP components; and These are the complex amplitude coefficients corresponding to the LCP and RCP components, respectively, which satisfy the normalization condition. , and The light intensity percentages corresponding to the two circularly polarized components.

[0051] For anisotropic liquid crystal molecules that satisfy the half-wave condition, when their optical axis coincides with the x-axis, the intrinsic Jones matrix under the linear polarization basis is... It can be represented as:

[0052]

[0053] In the formula, The complex amplitude transmission coefficient represents the optical axis direction. It represents the complex amplitude transmission coefficient perpendicular to the optical axis.

[0054] When the optical axis of the liquid crystal molecules rotates counterclockwise by an angle At that time, after coordinate rotation transformation, the rotated Jones matrix for:

[0055]

[0056] In the formula, Indicates rotation The rotation matrix.

[0057] To match the circular polarization basis decomposition of the incident light, the Jones matrix under the linear polarization basis is transformed using a basis transformation matrix. Transformation into the Jones matrix under circular polarization basis Substitute the half-wave condition , This can be simplified to:

[0058]

[0059] At this point, for any polarized incident light, its outgoing light field It can be represented as:

[0060]

[0061] in, This represents the incident light field. It can be observed that after incident light of any polarization state is modulated by the PB phase liquid crystal layer, the original LCP component is converted into orthogonal RCP components, with additional... The PB phase; the original RCP components are converted into orthogonal LCP, with additional The PB phase means that the incident light is converted into an orthogonal combination of LCP and RCP, and the two orthogonal circularly polarized components carry geometric phases with opposite signs. This characteristic provides the core physical basis for the device to achieve polarization-independent optical field manipulation.

[0062] Subsequently, the light beam passes through the transparent capping layer 20 and the chiral metasurface array layer 30. Thanks to the strong coupling resonance mechanism between the asymmetric L-shaped nanoantenna and the bilayer composite dielectric microcavity, the absorber exhibits extremely strong resonant ohmic loss for the first type of chiral circularly polarized light, achieving near-perfect absorption; simultaneously, it exhibits extremely high reflectivity for the second type of chiral circularly polarized light, and its polarization chirality flips with the change in transmission direction. For example, if left-handed circularly polarized light is incident on the metasurface, it will be converted into right-handed circularly polarized light after reflection.

[0063] The second type of chiral circularly polarized light, efficiently reflected, passes through the geometric phase liquid crystal layer 10 again from bottom to top. During this process, the beam not only undergoes another polarization spin flip but also a secondary spatial superposition of geometric phases. If the single-transmission geometric phase provided by the solid-state geometric phase liquid crystal layer at the current position is 2... After traveling back and forth along the optical path, the emitted cross-polarized beam ultimately achieved a total of 4 Geometric phase modulation. This 4x phase multiplication effect allows the device to complete wavefront shaping from 0 to 2π by introducing only a 90° change in the orientation of liquid crystal molecules in space, significantly reducing manufacturing difficulty and improving the optical efficiency of the device.

[0064] Figure 3This diagram illustrates the comparison of reflectance spectra of left-handed circularly polarized light (LCP) and right-handed circularly polarized light (RCP) incident on the device within the target operating wavelength range in this embodiment of the invention. The device employs a back-facing metal reflective layer structure, and its transmittance is negligible within the target operating wavelength range. Therefore, the light absorption rate can be directly calculated using the formula A = 1 - R (where R is the reflectance). As shown in the figure, near the center wavelength of 1200 nm, this chiral selective device exhibits a very strong difference in reflectance for the two orthogonally chiral circularly polarized lights, corresponding to significant chiral selective absorption characteristics. Taking the target absorbed light as LCP light as an example, its total reflectance curve is shown below. It drops to a near-zero value around 1200nm, corresponding to a near-perfect absorption effect with an absorption rate approaching 100%; at the same time, The absorption remains at an extremely high level of over 99% across the entire near-infrared communication band, corresponding to a weak absorption state with an absorption rate of less than 5%. This significant spectral contrast fully demonstrates that the device in this embodiment possesses excellent circular dichroism and chiral selectivity characteristics.

[0065] Figure 4 is a schematic diagram of the reflection polarization characteristics of the device in this embodiment for a specific chiral incident light. The figure shows in detail the change in polarization conversion efficiency (PCR) with wavelength. At the central operating wavelength near 1200 nm, the PCR peak value approaches 100%. This result indicates that the unabsorbed incident light beam achieves extremely efficient and high-purity polarization spin flipping during reflection.

[0066] Figure 5 This is a schematic diagram illustrating the variation of the geometric phase response of the reflected light beam from the device in an embodiment of the present invention with wavelength and spatial rotation angle. This diagram visually reveals the core of the present invention: 4 times (4 Geometric phase multiplication effect. At a resonant wavelength around 1200 nm, as the incident light passes through the solid geometric phase liquid crystal layer twice in the round trip optical path, when the optical axis orientation angle of the local liquid crystal molecules increases uniformly from 0 degrees to 90 degrees, the final phase of the emitted cross-polarized reflected light exhibits a perfect linear gradient change, completely covering the phase from 0 to 2. The complete phase space. It should be noted that, to exclude the influence of the propagation phase, the phase space is excluded here. The reference phase value at 0°. This characteristic not only confirms the device's excellent and continuous wavefront shaping capability, but also establishes a technological advantage at the physical level in reducing the difficulty of liquid crystal alignment processes. As a result, complex optical field manipulation applications such as beam deflection, polarization multiplexing communication, and holographic projection can be realized with simpler processes and lower costs.

[0067] Compared with the prior art, the present invention has the following significant advantages:

[0068] (1) This invention cleverly utilizes the reflective structure of the device to allow the light beam to pass through the solid geometric phase liquid crystal layer 10 twice within a single working cycle. If the geometric phase provided by the liquid crystal layer at a local location is 2... Each time the beam passes through, its polarization chirality flips, and the circularly polarized light that is ultimately reflected obtains a total of 4 Geometric phase modulation. This means that the optical axis orientation of liquid crystal molecules can be achieved from 0 to 2 simply by rotating 90° in space. The complete phase coverage completely avoids serious topological defects such as misalignment caused by the 180° rotation required by traditional devices, greatly reducing the difficulty of the optical orientation process.

[0069] (2) This invention solves the problem of traditional metasurfaces and nematic liquid crystal devices being extremely sensitive to incident polarization by decoupling the physical functions of the top liquid crystal and the bottom chiral metasurface. Any polarized or unpolarized light can be used as the working light source. The device can automatically decompose it and purify and reflect specific chiral components, which has extremely high light source compatibility in practical application systems such as lidar and polarization multiplexing.

[0070] (3) By employing nano-antennas that break in-plane symmetry, such as L-shaped structures with unequal-length orthogonal double arms, or L-shaped nano-antennas arranged in a specific configuration, and in conjunction with a bilayer composite dielectric substrate containing silicon nitride and silicon dioxide, a coupled multilayer microcavity with a maximum resonance depth is constructed within the target operating wavelength band. This structure can achieve absorption of the target circularly polarized light and high reflection of cross-polarized beams, with an extremely high polarization conversion efficiency (PCR), effectively suppressing stray light and polarization crosstalk.

[0071] (4) This invention abandons the complex electrical control scheme that requires external driving circuits and transparent electrodes such as ITO thin films, and adopts an all-solid-state passive cascade architecture. The bottom-level chiral selective absorber is fully compatible with standard CMOS micro-nano fabrication processes, which facilitates large-area, low-cost wafer-level mass production.

[0072] Based on the same inventive concept, this application also provides a method for controlling an optical field. Based on the polarization-independent chiral selective reflection and multidimensional optical field control device in any of the above embodiments, the method includes:

[0073] Incident light of arbitrary polarization state is modulated and decomposed by the geometric phase liquid crystal layer 10, and outputs circularly polarized light of the first chirality and circularly polarized light of the second chirality.

[0074] The chiral metasurface array layer 30 absorbs circularly polarized light of the first chirality and reflects circularly polarized light of the second chirality;

[0075] The reflected circularly polarized light passes through the geometric phase liquid crystal layer 10 and exits, achieving two-way modulation.

[0076] In one embodiment, the method further includes: by changing the geometric dimensions and spatial arrangement of the subwavelength nanoantennas in the chiral metasurface array layer 30, in coordination with the geometric phase liquid crystal layer 10, four times geometric phase modulation of the incident light is achieved, while polarization state conversion and wavelength selective response of the outgoing beam are achieved, thereby completing the control of the multidimensional light field.

[0077] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A polarization-independent chiral selective reflection and multidimensional optical field manipulation device, wherein the device has a multilayer stacked structure, characterized in that, From top to bottom, they include: A geometric phase liquid crystal layer is used to provide a spatially continuously varying geometric phase distribution and to convert incident light of arbitrary polarization state into orthogonally circularly polarized light with opposite chirality. A transparent overlay is used to provide structural support and protection, as well as refractive index matching; A chiral metasurface array layer, composed of subwavelength nanoantennas, is used to apply asymmetric modulation of absorption or reflection of circularly polarized light with opposite chirality. Dielectric substrate layer, used to form optical microcavities; Total reflection layer, used to block light beam transmission and create reflection.

2. The device according to claim 1, characterized in that: The geometric phase liquid crystal layer is a passive polymer film with a fixed optical axis orientation, and the optical axis orientation angle of the liquid crystal molecules is distributed in a one-dimensional or two-dimensional gradient in the plane.

3. The device according to claim 1, characterized in that: The subwavelength nanoantennas in the chiral metasurface array layer are arbitrary two-dimensional or three-dimensional geometric configurations that satisfy the condition of breaking in-plane mirror symmetry.

4. The device according to claim 1, characterized in that: The subwavelength nanoantenna in the chiral metasurface array layer is a metallic material with plasmon effect.

5. The device according to claim 1, characterized in that: The dielectric substrate layer is a multilayer composite dielectric structure.

6. The device according to claim 1, characterized in that: The thickness of the total reflection layer is greater than the optical skin depth of the target operating band of the device.

7. The device according to claim 6, characterized in that: The target operating band of the device is the near-infrared band.

8. The device according to claim 1, characterized in that: The device is configured in a system that includes a beam deflector, a wavefront shaper, and a polarization multiplexer.

9. A method for controlling an optical field, characterized in that, Based on the polarization-independent chiral selective reflection and multidimensional optical field manipulation device as described in any one of claims 1 to 8, the method includes: Incident light of any polarization state is modulated and decomposed by the geometric phase liquid crystal layer, and outputs circularly polarized light of the first chirality and circularly polarized light of the second chirality. The chiral metasurface array layer absorbs the first type of chiral circularly polarized light and reflects the second type of chiral circularly polarized light; The reflected circularly polarized light of the second chirality passes through the geometric phase liquid crystal layer and exits, achieving two-way modulation.

10. The method according to claim 9, characterized in that, The method further includes: By changing the geometric dimensions and spatial arrangement of the subwavelength nanoantennas in the chiral metasurface array layer, and in coordination with the geometric phase liquid crystal layer, four times geometric phase modulation of the incident light is achieved, while polarization state conversion and wavelength selective response of the outgoing beam are realized, thus completing multidimensional optical field manipulation.

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