WO2020140392A1 - 线偏振光转换元件、制备方法和线偏振光转换系统 - Google Patents

线偏振光转换元件、制备方法和线偏振光转换系统 Download PDF

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WO2020140392A1
WO2020140392A1 PCT/CN2019/091154 CN2019091154W WO2020140392A1 WO 2020140392 A1 WO2020140392 A1 WO 2020140392A1 CN 2019091154 W CN2019091154 W CN 2019091154W WO 2020140392 A1 WO2020140392 A1 WO 2020140392A1
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sub
linearly polarized
light
wavelength structure
substrate
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PCT/CN2019/091154
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English (en)
French (fr)
Inventor
李贵新
刘言军
毛宁斌
刘萱
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Southern University of Science and Technology
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Southern University of Science and Technology
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Priority to KR1020217022740A priority Critical patent/KR20210106516A/ko
Priority to DE112019006566.1T priority patent/DE112019006566T5/de
Priority to JP2021539060A priority patent/JP2022519015A/ja
Priority to US17/420,328 priority patent/US20220099861A1/en
Publication of WO2020140392A1 publication Critical patent/WO2020140392A1/zh
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G02B5/1809—Diffraction gratings with pitch less than or comparable to the wavelength
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/002—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of materials engineered to provide properties not available in nature, e.g. metamaterials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D11/00—Producing optical elements, e.g. lenses or prisms
    • B29D11/00634—Production of filters
    • B29D11/00644—Production of filters polarizing
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/02—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of crystals, e.g. rock-salt, semi-conductors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
    • G02B27/286—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/70—Microphotolithographic exposure; Apparatus therefor
    • G03F7/70058—Mask illumination systems
    • G03F7/70191—Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • G02F1/133753—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle
    • G02F1/133757—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle with different alignment orientations
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
    • G02F1/13378—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation
    • G02F1/133788—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by treatment of the surface, e.g. embossing, rubbing or light irradiation by light irradiation, e.g. linearly polarised light photo-polymerisation

Definitions

  • the embodiments of the present application relate to the technical field of superstructured surfaces, for example, to a linearly polarized light conversion element, a preparation method, and a linearly polarized light conversion system.
  • Liquid crystal is a unique material with both liquid and crystal properties, and is widely used in various types of liquid crystal displays. Under the action of an electric field, the arrangement structure of liquid crystal molecules will change, and at the same time their optical properties will also change, which is the basis of liquid crystal display. The orderly arrangement of the liquid crystal in the display screen is achieved by the pre-orientation on the interface of the liquid crystal and the substrate.
  • the liquid crystal alignment is a technology developed for this purpose.
  • Liquid crystal light alignment technology is a non-contact method to achieve liquid crystal alignment through polarized light irradiation. Unlike the friction alignment method, it has the advantages of no pollution, no static electricity and easy to achieve multi-area orientation.
  • the photo-controlled alignment technology utilizes photosensitive materials to undergo directional photo-crosslinking, isomerization or photo-cleavage reaction under ultraviolet polarized light irradiation to induce alignment of liquid crystal molecules.
  • the present application proposes a linearly polarized light conversion element, a preparation method, and a linearly polarized light conversion system, so as to realize the adjustment of the polarization direction of the light beam, thereby facilitating the realization of liquid crystal light-oriented orientation with high spatial resolution.
  • An embodiment of the present application provides a linearly polarized light conversion element, including:
  • a metamorphic surface on the substrate is A metamorphic surface on the substrate
  • the superstructured surface includes at least one light field control region, each of the light field control regions includes at least one superstructured surface functional unit, and each of the superstructured surface functional units includes an anisotropic sub-wavelength structure, In the same light field control region, the long axis directions of each of the sub-wavelength structures are consistent.
  • An embodiment of the present application provides a linearly polarized light conversion system, including a laser, a beam shaper, a linear polarizer, and a linearly polarized light conversion element of any embodiment of the present application;
  • the laser is configured to provide a laser light source; the beam shaper is configured to shape the laser light emitted by the laser; the linear polarizer is configured to convert the shaped laser light into linearly polarized incident light and propagate to the The superstructured surface of the linearly polarized light conversion element.
  • the embodiments of the present application provide a method for preparing a linearly polarized light conversion element, including:
  • a metamorphic surface is formed on the substrate, wherein the metamorphic surface includes a plurality of metamorphic surface functional units, and the metamorphic surface functional unit includes an anisotropic sub-wavelength structure based on a line The polarization direction of the polarized incident light and the linear polarization state of the desired outgoing light are distributed and arranged.
  • FIG. 1 is a schematic plan view of a linearly polarized light conversion element provided by an embodiment of the present application
  • FIG. 2 is a schematic cross-sectional structural diagram of a linearly polarized light conversion element provided by an embodiment of the present application
  • FIG. 3 is a schematic diagram of the structure and principle of a linearly polarized light conversion system provided by an embodiment of the present application;
  • FIG. 5 is a schematic diagram of an arrangement of a sub-wavelength structure provided by an embodiment of the present application.
  • FIG. 6 is a flowchart of a method for manufacturing a linearly polarized light conversion element provided by an embodiment of the present application
  • FIG. 7 is a flowchart of a specific preparation method of a linearly polarized light conversion element provided by an embodiment of the present application.
  • FIGS. 8-12 are structural schematic diagrams corresponding to each process flow in the method for manufacturing a linearly polarized light conversion element provided by an embodiment of the present application.
  • a photosensitive molecular material (photo-controlled alignment layer) is first coated on a substrate, and then the photo-controlled alignment layer is irradiated with ultraviolet polarized light to induce the alignment of liquid crystal molecules.
  • the non-uniform orientation distribution can be achieved by changing the optical reticle and multiple exposure methods.
  • the light-controlled orientation method based on the spatial light modulator Spatial Light Modulator, SLM
  • SLM Spatial Light Modulator
  • micro-projection system based on digital micro-mirror device (DMD) controls a single pixel (single micro-mirror) on the DMD through micro-electromechanical systems (MEMS) to display different reflections.
  • MEMS micro-electromechanical systems
  • the above-mentioned optical control orientation method requires a complicated optical system, which is bulky and expensive. It needs to be completed through multiple exposures, which is not conducive to the manufacture of large-area, high-precision liquid crystal photonics devices. Moreover, the implementation based on the spatial light modulator and the numerically controlled micromirror array is difficult to achieve the orientation of liquid crystal molecules with high spatial resolution (such as 1 ⁇ m).
  • Embodiments of the present application provide a linearly polarized light conversion element, which can realize the adjustment of at least one polarization direction of linearly polarized incident light to generate a vector light field distribution (at least one linearly polarized state distribution) with sub-wavelength spatial resolution ).
  • FIG. 1 is a schematic diagram of a planar structure of a linearly polarized light conversion element provided by an embodiment of the present application
  • FIG. 2 is a schematic diagram of a cross-sectional structure of a linearly polarized light conversion element provided by an embodiment of the present application.
  • the linearly polarized light conversion element is suitable for the liquid crystal light-oriented alignment technology. As shown in FIGS. 1 and 2, the linearly polarized light conversion element provided in this embodiment includes:
  • the metasurface 2 is located on the substrate 1;
  • the superstructure surface 2 includes at least one light field control region 100, and each light field control region 100 includes at least one superstructure surface functional unit 20.
  • the superstructure surface functional unit 20 includes an anisotropic sub-wavelength structure 201 in the same In the light field control region 100, the direction of the long axis of each sub-wavelength structure 201 is the same.
  • the metasurface is an interface composed of metamorphic surface functional units (subwavelength metamorphic functional elements) with spatial changes, which can effectively adjust the polarization, amplitude and phase of light; it can be used to realize high-efficiency optical Holographic imaging, high numerical aperture lenses and generating optical orbital angular momentum.
  • the two-dimensional nature of the metasurface reduces the difficulty of processing, and has the advantages of compact size and low loss, and is compatible with existing complementary metal oxide semiconductor technology.
  • the above-mentioned light field regulation area 100 can be understood as an area corresponding to the arrangement of the sub-wavelength structure 201 or the linear polarization state distribution of the desired outgoing light.
  • a light field regulation area 100 the arrangement of the sub-wavelength structure 201 is consistent, The polarization direction of the light exiting through the light field regulation area 100 is the same, and the division of the light field regulation area 100 is convenient for understanding the overall arrangement of the sub-wavelength structure 201.
  • the material of the substrate 1 may be transparent materials such as silicon, glass, or ITO; the shape of the sub-wavelength structure 201 is a rod or an ellipse.
  • the design principle of the linearly polarized light conversion element is: the principle of Bailey geometric phase, that is, the interaction between circularly polarized light and anisotropic sub-wavelength structure can make the circular polarization of incident circularly polarized light State inversion while introducing geometric phase factor
  • the azimuth angle of the anisotropic sub-wavelength structure can realize the continuous adjustment of the phase of the incident light from 0-2 ⁇ , and the phase change sign caused by the incident light of different circular polarization states is opposite.
  • the incident linearly polarized light can be decomposed into left-handed circularly polarized light and right-handed circularly polarized light.
  • the left-handed circularly polarized light and the right-handed circularly polarized light undergo a sub-wavelength structure to produce phase changes of equal magnitude and opposite signs, and the synthesis can form linear polarization again Light, and the polarization direction is It can be seen that by simply changing the azimuth angle of the anisotropic sub-wavelength structure, the polarization direction of the incident linearly polarized light can be adjusted, while the azimuth angle of the sub-wavelength structure and the long-axis direction and line of the sub-wavelength structure The polarization direction of the polarized incident light is related.
  • the linear polarization state distribution of the outgoing light used for exposing the light-controlled alignment layer can be determined according to the desired liquid crystal molecular orientation distribution, wherein the orientation direction of the liquid crystal molecules and the outgoing light The linear polarization direction is consistent. Therefore, the arrangement of the sub-wavelength structure is determined based on the linear polarization state distribution of the outgoing light, and the preparation of the superstructured surface having the subwavelength structure of the arrangement is performed to obtain a linearly polarized light conversion element. In this way, the orientation of liquid crystal molecules can be controlled at the sub-wavelength scale, and the liquid crystal light-oriented alignment with high spatial resolution can be achieved.
  • each light field control area includes at least one metasurface function unit, and each metasurface function unit It includes an anisotropic sub-wavelength structure, and in the same light field regulation area, the long axis direction (arrangement) of each sub-wavelength structure is consistent; thus, the linearly polarized incident light in the same polarization direction passes through the linearly polarized light conversion element
  • each light field regulation area can convert the polarization direction of the incident linearly polarized incident light into another polarization direction The light exits, thereby realizing the adjustment of the polarization direction of the light beam, and can be repeatedly used stably and repeatedly.
  • the arrangement of sub-wavelength structures in the superstructure surface can be designed according to the required linear polarization state distribution of the outgoing light, so as to obtain the linearly polarized light conversion element of the present application, and then the linearly polarized light conversion element can be used to pass the
  • the linearly polarized light conversion element converts linearly polarized incident light into at least one beam of linearly polarized light, and at least one exposure field of the light control alignment layer is exposed at one time, so that at least one alignment of the light control alignment layer can be achieved, and then the liquid crystal can be realized.
  • the molecular orientation is simple, the process flow is simple, the cost is low, and the orientation of the liquid crystal molecules can be controlled at the sub-wavelength scale, which realizes the liquid crystal light-oriented orientation with high spatial resolution.
  • At least one light field control region 100 includes two or more light field control regions 100 (the four light field control regions 100 are shown in the figure), and different light field control regions
  • the sub-wavelength structure 201 in 100 has a different long axis direction.
  • the same linearly polarized incident light passes through different light field control regions 100 of the metasurface at the same time, it can output outgoing light different from the polarization direction of the linearly polarized incident light, and corresponds to the polarization direction of the outgoing light of different light field control regions 100
  • multiple vector light fields can be generated at the same time, increasing the number of samples in a single exposure and improving production efficiency.
  • the linearly polarized light conversion element is used for light-controlled alignment of liquid crystal molecules, a non-uniform alignment distribution of liquid crystal molecules can be achieved by only one exposure, which reduces the number of exposures and simplifies the process of light-controlled alignment Process.
  • the azimuth angle of the sub-wavelength structure when the azimuth angle of the sub-wavelength structure is fixed, after determining the exit angle of the outgoing light projected onto the exposure field of the light-controlled alignment layer, it can be combined with ray optics and generalized reflection law to determine the incidence to linear polarization The angle of incidence of the linearly polarized incident light of the light conversion element (superstructure surface). In this way, the exit angle of the emitted light can be adjusted by adjusting the incident angle of the linearly polarized incident light, so as to realize the exposure to the exposure field of the light control alignment layer and the alignment of the corresponding liquid crystal molecules.
  • FIG. 1 is only used to illustrate the arrangement of the sub-wavelength structure, and the specific arrangement depends on the actual situation.
  • the above linearly polarized light conversion element can control the polarization direction of the linearly polarized incident light by reflecting or transmitting the linearly polarized incident light.
  • the metamorphic surface in the linearly polarized light conversion element can be a reflective metamorphic surface Or transmissive metasurface.
  • the superstructured surface/superstructured surface functional unit may include a stacked structure of a metal reflective layer 202, a dielectric layer 203, and a metal sub-wavelength structure 201 (refer to FIG.
  • the structured surface functional unit may include a laminated structure of a metal reflective layer and a metal subwavelength structure, or the superstructured surface functional unit may include a laminated structure of a metal reflective layer and a dielectric subwavelength structure; for a transmissive superstructured surface, a superstructured surface
  • the functional unit may include a dielectric sub-wavelength structure.
  • the linearly polarized light conversion system 10 includes a laser 101, a beam shaper 102, a linear polarizer 103, and the foregoing The linear polarization conversion element 104 provided in the embodiment.
  • the laser 101 is configured to provide a laser light source; the beam shaper 102 is configured to shape the laser light emitted by the laser 101; the linear polarizer 103 is configured to convert the shaped laser into linearly polarized incident light and propagate to linearly polarized light conversion The metasurface of element 104.
  • the beam shaper 102 may be a Gaussian flat-top beam converter or a spatial filtering collimation system.
  • the linearly polarized light conversion system 10 may be a liquid crystal light-oriented alignment system.
  • the laser light emitted by the laser 101 passes through the beam shaper 102 and the linear polarizer 103 to form a superstructure surface where linearly polarized incident light is incident on the linearly polarized light conversion element 104, referring to any of the embodiments provided above
  • the function of the linearly polarized light conversion element 104, the linearly polarized light conversion element 104 can convert the linearly polarized incident light into the outgoing light that satisfies the required linear polarization distribution state, and project the outgoing light onto the conductive glass substrate 30 pre-spin coated
  • the light control alignment layer 31 completes the alignment of the light control alignment layer 31, so as to achieve a high-resolution spatial arrangement and distribution of the liquid crystal molecules 32 between the light control alignment layers 31.
  • linearly polarized light conversion system provided by this embodiment, including the linearly polarized light conversion element provided by the embodiment of the present application, has corresponding functions and beneficial effects.
  • the special liquid crystal photonics devices (such as beam splitters) prepared by the above linearly polarized light conversion system can also be used to generate and control special light fields (such as vortex beams, Bessel beams and Airy beam, etc.).
  • a liquid crystal photonic device that can generate and control a vortex beam by the linearly polarized light conversion system of the present application is taken as an example for description.
  • the vortex beam has a spiral equal phase surface, each photon has Orbital angular momentum, where m is the topological quantum number, which can be any integer, representing the orbital angular momentum index, different values correspond to mutually orthogonal angular momentum states, Is the reduced Planck constant.
  • the center of the vortex beam is a phase singularity, where the amplitude is zero, so it exhibits a circular light field distribution.
  • Vortex beams are widely used in optical tweezers, optical communications, super-resolution imaging, and astronomical observations.
  • the arrangement pattern of sub-wavelength structures can be designed based on the fork-shaped interference pattern (such as (Shown in Figure 5), and then using the super-surface structure of the sub-wavelength structure shown in Figure 5 to orient the liquid crystal molecules, the liquid crystal molecules can be aligned to the fork-shaped interference pattern shown in Figure 4, and then irradiated with reference light can be generated Vortex light.
  • yet another embodiment of the present application provides a method for manufacturing a linearly polarized light conversion element. As shown in FIG. 6, the method for preparing the linearly polarized light conversion element includes steps 110 and 120.
  • step 110 a substrate is provided.
  • the material of the substrate 1 may be transparent materials such as silicon, glass, or ITO.
  • step 120 a metasurface is formed on the substrate.
  • the superstructured surface includes a plurality of superstructured surface functional units.
  • the superstructured surface functional unit includes an anisotropic sub-wavelength structure.
  • the sub-wavelength structure is based on the polarization direction of the linearly polarized incident light and the linear polarization state distribution of the desired outgoing light. Arrange.
  • forming the metamorphic surface on the substrate may include: determining the azimuth distribution of the sub-wavelength structure on the plane of the metamorphic surface on the plane according to the linear polarization state distribution of the desired outgoing light, where the azimuth angle is sub The angle between the long axis direction of the wavelength structure and the polarization direction of the linearly polarized incident light incident on the linearly polarized light conversion element; according to the polarization direction and azimuth distribution of the linearly polarized incident light, the arrangement pattern of the sub-wavelength structure is determined; Based on the arrangement pattern of sub-wavelength structures, at least sub-wavelength structures are formed on the substrate.
  • forming at least the sub-wavelength structure on the substrate may include: forming a metal reflection layer and a dielectric layer stacked in sequence on the substrate; the dielectric layer is far away from the substrate The surface of one side is spin-coated with photoresist or e-beam resist; photoresist or e-beam resist is used to remove part of the photoresist or e-beam resist, and a sub-wavelength is formed at the removed photoresist or e-beam resist Arrangement pattern of the structure; a layer of metal is evaporated on the entire surface; the remaining photoresist or e-beam resist is dissolved, and the metal deposited on the photoresist or e-beam resist is removed, so that the remaining metal forms a sub-wavelength structure.
  • the method for manufacturing the linearly polarized light conversion element includes: steps 210 to 280.
  • step 210 a substrate is provided.
  • step 220 the azimuth distribution of the sub-wavelength structure on the superstructure surface in the plane is determined according to the linear polarization state distribution of the desired outgoing light.
  • the azimuth angle is the angle between the long axis direction of the sub-wavelength structure and the polarization direction of the linearly polarized incident light incident on the linearly polarized light conversion element.
  • the polarization direction of the outgoing light in each region on the metasurface can be determined.
  • the outgoing light's polarization direction is of sub-wavelength structure
  • the azimuth is doubled, so the azimuth distribution of the sub-wavelength structure on the plane can be determined.
  • step 230 the arrangement pattern of the sub-wavelength structure is determined according to the polarization direction and azimuth distribution of the linearly polarized incident light.
  • the azimuth angle is the angle between the long axis direction of the sub-wavelength structure and the polarization direction of the linearly polarized incident light incident on the linearly polarized light conversion element, under the condition that the polarization direction of the linearly polarized incident light is constant, according to step 220
  • the obtained azimuth distribution can determine the long axis direction of the sub-wavelength structure of each region on the metasurface, and then determine the arrangement pattern of the sub-wavelength structure.
  • step 240 a metal reflective layer and a dielectric layer that are sequentially stacked are formed on the substrate by evaporation.
  • a metal reflective layer 202 and a dielectric layer 203 which are sequentially stacked are formed on the substrate 1 by evaporation.
  • the material of the metal reflective layer 202 may be aluminum or gold, and the material of the dielectric layer 203 may be silicon dioxide.
  • the metal reflective layer 202 and the dielectric layer 203 may be sequentially vapor-deposited on the substrate 1 by using thermal evaporation or electron beam evaporation technology.
  • step 250 photoresist or electron beam resist is spin-coated on the surface of the dielectric layer away from the substrate.
  • a photoresist 40 or an electron beam resist is spin-coated on the surface of the dielectric layer 203 away from the substrate 1.
  • step 260 photoresist or e-beam resist is etched to remove part of the photoresist or e-beam resist, and an arrangement pattern of sub-wavelength structures is formed at the removed photoresist or e-beam resist.
  • ultraviolet lithography is used to expose the photoresist 40
  • electron beam lithography is used to expose the electron beam resist
  • the corresponding developer is used to remove the exposed photoresist 40 or the electron beam resist
  • the corresponding developer is used to remove the exposed photoresist 40 or the electron beam resist
  • step 270 a layer of metal is deposited on the entire surface.
  • a layer of metal 50 is vapor-deposited on the surface of the dielectric layer 203 and the remaining photoresist 40 or the surface of the electron beam resin by an electron beam evaporation process or a thermal evaporation process.
  • step 280 the remaining photoresist or e-beam resist is dissolved, and the metal deposited on the photoresist or e-beam resist is removed, so that the remaining metal forms a sub-wavelength structure.
  • the remaining photoresist 40 or e-beam resist is removed using a corresponding stripping solution, so that the metal on the remaining photoresist 40 or e-beam resist is peeled off, and the medium is retained
  • the metal layer on the surface of the layer 203 forms the sub-wavelength structure 201.
  • a linearly polarized light conversion element having a reflective metasurface can be prepared.
  • the above embodiment only exemplarily describes a metal reflective layer 202, a dielectric layer 203, and a metal sub-wavelength structure 201
  • the reflective superstructure surface of the linearly polarized light conversion element of the present application may also include a stacked structure of a metal reflection layer and a metal sub-wavelength structure, or a metal reflection layer and a medium
  • the specific preparation method of the laminated structure of the sub-wavelength structure can be reasonably derived based on the preparation method of the linearly polarized light conversion element of this embodiment, and will not be repeated here.
  • the embodiments of the present application also provide a method for manufacturing a linearly polarized light conversion element having a transmissive superstructure surface, which may specifically include the following steps: step 310 to step 390.
  • step 310 a transparent substrate is provided.
  • step 320 according to the linear polarization state distribution of the desired outgoing light, the azimuth distribution of the sub-wavelength structure on the plane on the metasurface is determined.
  • step 330 the arrangement pattern of the sub-wavelength structure is determined according to the polarization direction and azimuth distribution of the linearly polarized incident light.
  • step 340 a dielectric layer is evaporated or deposited on the transparent substrate.
  • the material of the dielectric layer may be silicon, silicon nitride, or titanium dioxide.
  • step 350 photoresist or electron beam resist is spin-coated on the surface of the dielectric layer away from the substrate.
  • step 360 photoresist or e-beam resist is etched to remove part of the photoresist or e-beam resist, and an arrangement pattern of sub-wavelength structures is formed at the removed photoresist or e-beam resist.
  • step 370 a protective layer is deposited on the entire surface.
  • the material of the protective layer may be chromium.
  • step 380 the remaining photoresist or e-beam resist is dissolved, and the protective layer deposited on the photoresist or e-beam resist is removed.
  • step 390 using the remaining protective layer as a mask, the dielectric layer not covering the protective layer is etched, and the remaining protective layer is removed, so that the remaining dielectric layer forms a sub-wavelength structure.
  • the linear polarization state distribution of the desired outgoing light is determined by the orientation direction of the liquid crystal to be aligned.
  • the linear polarization state distribution of the desired outgoing light can be determined based on the orientation direction of the liquid crystal to be aligned, and then a liquid crystal light-oriented alignment system for liquid crystal light-oriented alignment can be prepared, which can control the orientation of liquid crystal molecules at a sub-wavelength scale to achieve high space Resolution liquid crystal light-oriented orientation.
  • the application can also be based on the principle of surface plasmon resonance, by adjusting the parameters of the sub-wavelength structure (such as length and width) to improve the optical reflection efficiency of the metasurface, thereby improving the utilization of linearly polarized incident light and reducing linear Loss of polarized incident light.

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Abstract

提供了一种线偏振光转换元件、制备方法和线偏振光转换系统。线偏振光转换元件包括：衬底（1）；超构表面（（2），位于衬底1）上；其中，超构表面（2）包括至少一个光场调控区（100），每个光场调控区（100）包括至少一个超构表面功能单元（20），超构表面功能单元（20）包括各向异性的亚波长结构（201），在同一光场调控区（100）中，每个亚波长结构（201）的长轴方向一致。

Description

线偏振光转换元件、制备方法和线偏振光转换系统
本申请要求在2019年01月04日提交中国专利局、申请号为201910007580.X的中国专利申请的优先权，该申请的全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及超构表面技术领域，例如涉及一种线偏振光转换元件、制备方法和线偏振光转换系统。
背景技术
液晶是兼有液体和晶体两方面性质的独特材料,广泛用于各类液晶显示器。液晶分子在电场作用下，其排列结构会发生转变，同时其光学特性也会发生变化，这也是液晶显示的基础。液晶在显示屏里的有序排列是通过液晶与基板界面上的预取向来实现的，液晶取向就是为了达到这一目的而发展起来的技术。
目前液晶取向技术主要包括摩擦取向法和光控取向法等。液晶光控取向技术是一种通过偏振光照射来实现液晶取向的非接触式方法,不同于摩擦取向法,它具有无污染、无静电和易实现区域多取向等优点。光控取向技术利用光敏材料在紫外线偏光照射下发生定向光交联、异构化或光裂解反应进而诱导液晶分子定向排列。
然而，现有液晶光控取向技术大多数仅能实现均匀的取向分布。为实现可控的非均匀取向分布，往往需要复杂的光学系统，体积庞大，成本高。需要经过多次曝光完成，不利于实现大面积及高精度的液晶光子学器件制造。另外，基于空间光调制器和数控微镜阵列的实施方案难以实现高空间分辨率(比如1μm)的液晶分子取向。
发明内容
有鉴于此，本申请提出一种线偏振光转换元件、制备方法和线偏振光转换系统，以实现对光束偏振方向的调控，从而可便于实现高空间分辨率的液晶光控取向。
本申请实施例提供了一种线偏振光转换元件，包括：
衬底；
超构表面，位于所述衬底上；
其中，所述超构表面包括至少一个光场调控区，每个所述光场调控区包括至少一个超构表面功能单元，每个所述超构表面功能单元包括各向异性的亚波长结构，在同一所述光场调控区中，每个所述亚波长结构的长轴方向一致。
本申请实施例提供了一种线偏振光转换系统，包括激光器、光束整形器、线偏振片和本申请任一实施例的线偏振光转换元件；
所述激光器设置为提供激光光源；所述光束整形器设置为对所述激光器出射的激光进行整形；所述线偏振片设置为将整形后的激光变换成线偏振入射光，并传播至所述线偏振光转换元件的超构表面。
本申请实施例提供了一种线偏振光转换元件的制备方法，包括：
提供衬底；
在所述衬底上形成超构表面，其中，所述超构表面包括多个超构表面功能单元，所述超构表面功能单元包括各向异性的亚波长结构，所述亚波长结构基于线偏振入射光的偏振方向以及所需出射光的线偏振状态分布而排布。
附图概述
下面将通过参照附图详细描述本申请的示例性实施例，使本领域的普通技术人员更清楚本申请的上述及其他特征和优点，附图中：
图1是本申请实施例提供的线偏振光转换元件的平面结构示意图；
图2是本申请实施例提供的线偏振光转换元件的剖面结构示意图；
图3是本申请实施例提供的线偏振光转换系统的结构及原理示意图；
图4是本申请实施例提供的涡旋光束和参考光的叉形干涉图样；
图5是本申请实施例提供的一种亚波长结构的排布示意图；
图6是本申请实施例提供的线偏振光转换元件的制备方法的流程图；
图7是本申请实施例提供的线偏振光转换元件具体制备方法的流程图；
图8-图12是本申请实施例提供的线偏振光转换元件的制备方法中各工艺流程对应的结构示意图。
具体实施方式
下面结合附图并通过具体实施方式来进一步说明本申请的技术方案。可以理解的是，此处所描述的具体实施例仅仅用于解释本申请，而非对本申请的限 定。另外还需要说明的是，为了便于描述，附图中仅示出了与本申请相关的部分而非全部结构。
目前，一般光控取向法中，首先在衬底上涂敷光敏分子材料(光控取向层),然后用紫外偏振光照射光控取向层进而诱导液晶分子的取向。可通过变换光学掩模版和多次曝光的方法实现非均匀取向分布。而基于空间光调制器(Spatial Light Modulator，SLM)的光控取向法可根据需要灵活控制局部偏振光的偏振方向，从而灵活控制液晶分子取向。另外，基于数控微镜阵列(Digital Micro-mirror Device，DMD)的缩微投影系统，通过微机电系统(Micro-Electro-Mechanical Systems，MEMS)控制DMD上的单个像素(单个微镜)呈现不同的反转状态来实现动态掩模，来实现对液晶取向结构图案和取向方向的动态控制。
但上述光控取向法需要复杂的光学系统，体积庞大，成本高。需要经过多次曝光完成，不利于实现大面积、高精度的液晶光子学器件制造。且基于空间光调制器和数控微镜阵列的实施方案难以实现高空间分辨率(比如1μm)的液晶分子取向。
本申请实施例提供了一种线偏振光转换元件，可实现对一线偏振入射光进行至少一种偏振方向的调控，产生具有亚波长空间分辨率的矢量光场分布(至少一种线偏振状态分布)。
图1是本申请实施例提供的线偏振光转换元件的平面结构示意图；图2是本申请实施例提供的线偏振光转换元件的剖面结构示意图。该线偏振光转换元件适用于液晶光控取向技术，如图1和图2所示，本实施例提供的线偏振光转换元件包括：
衬底1；
超构表面2，位于衬底1上；
其中，超构表面2包括至少一个光场调控区100，每个光场调控区100包括至少一个超构表面功能单元20，超构表面功能单元20包括各向异性的亚波长结构201，在同一光场调控区100中，每个亚波长结构201的长轴方向一致。
本实施例中，超构表面是由具有空间变化的超构表面功能单元(亚波长超构功能基元)构成的界面，可以有效调控光的偏振、振幅和相位；可用于实现高效率的光学全息成像、高数值孔径透镜和产生光学轨道角动量等。超构表面的二维属性降低了加工难度，并具有体积紧凑，损耗低的优势，与现有的互补金属氧化物半导体技术兼容。
上述光场调控区100可以理解为根据亚波长结构201的排布或所需出射光的线偏振状态分布对应划分的区域，在一个光场调控区100中，亚波长结构201的排布一致，经该光场调控区100出射的光的偏振方向一致，该光场调控区100的划分便于理解亚波长结构201的整体排布情况。上述衬底1的材料可以为硅、玻璃、或ITO等透明材料；亚波长结构201的形状为棒状或椭圆形。
基于上述技术方案，本实施例提供的线偏振光转换元件设计原理为：由贝里几何相位原理，即圆偏振光与各向异性的亚波长结构相互作用，可以使入射圆偏振光的圆偏振态发生反转同时引入几何相位因子
Figure PCTCN2019091154-appb-000001
其中σ＝±1代表入射光的圆偏振态；
Figure PCTCN2019091154-appb-000002
是各向异性的亚波长结构在平面上的方位角(亚波长结构的长轴方向与入射至线偏振光转换元件的线偏振入射光的偏振方向之间的夹角)，因而，通过简单改变各向异性的亚波长结构的方位角可实现对入射光相位从0-2π的连续调控，且不同圆偏振状态的入射光引起的相位变化符号相反。而入射的线偏振光可分解为左旋圆偏振光和右旋圆偏振光，左旋圆偏振光和右旋圆偏振光经过亚波长结构产生大小相等，符号相反的相位变化，合成可再次形成线偏振光，且偏振方向为
Figure PCTCN2019091154-appb-000003
由此可以看出，通过简单改变各向异性的亚波长结构的方位角可实现对入射的线偏振光的偏振方向进行调控，而亚波长结构的方位角与亚波长结构的长轴方向及线偏振入射光的偏振方向相关，因此，在线偏振入射光的偏振方向一定时，根据所需出射光的线偏振状态分布，通过排布亚波长结构，即设置亚波长结构的长轴方向，便可实现对线偏振入射光的偏振方向的调控，使出射光满足所需出射光的线偏振状态分布。
在一实施例中，针对液晶光控取向技术，可根据所需液晶分子取向分布，确定用于曝光光控取向层的出射光的线偏振状态分布，其中，液晶分子的取向方向与出射光的线偏振方向一致。从而基于该出射光的线偏振状态分布确定亚波长结构的排布，进行制备具有该排布的亚波长结构的超构表面得到线偏振光转换元件。由此可在亚波长尺度控制液晶分子取向，实现了高空间分辨率的液晶光控取向。
本实施例利用超构表面设计线偏振光转换元件，通过将超构表面划分为至少一个光场调控区，每个光场调控区包括至少一个超构表面功能单元，每个超构表面功能单元包括一个各向异性的亚波长结构，且在同一光场调控区中，每个亚波长结构的长轴方向(排布)一致；由此，同一偏振方向的线偏振入射光经线偏振光转换元件的超构表面反射或透射后，基于每个光场调控区的亚波长 结构的排布，每个光场调控区可将对应入射的线偏振入射光经的偏振方向转换成另一偏振方向的光出射，从而实现了对光束偏振方向的调控，且可稳定多次重复使用。同时，可根据所需的出射光的线偏振状态分布，设计超构表面中亚波长结构的排布，从而得到本申请的线偏振光转换元件，进而可利用该线偏振光转换元件，通过该线偏振光转换元件将线偏振入射光转换成至少一束线偏振光，对光控取向层的至少一个曝光场进行一次曝光，便可实现对光控取向层至少一种取向，进而实现对液晶分子相应的取向，工艺流程简单，成本低，且可在亚波长尺度控制液晶分子取向，实现了高空间分辨率的液晶光控取向。
在一实施例中，继续参考图1，至少一个光场调控区100包括两个或多个光场调控区100(图中示出了4个光场调控区100)，不同的光场调控区100中的亚波长结构201的长轴方向不同。
由此，同一线偏振入射光同时经过超构表面不同的光场调控区100后，可输出不同于线偏振入射光偏振方向的出射光，且对应不同光场调控区100的出射光的偏振方向不同，进而可同时产生多束矢量光场，增加单次曝光样品的数量，提高生产效率。在一实施例中，在利用该线偏振光转换元件对液晶分子进行光控取向时，仅通过一次曝光便可实现液晶分子的非均匀取向分布，减少了曝光次数，简化了光控取向的工艺流程。同时，基于上述贝里几何相位原理还可以看出，通过简单改变各向异性的亚波长结构的方位角可实现对入射光相位从0-2π的连续调控，而入射光不同的相位可以引起反射光不同角度的偏转，进而可以通过设置亚波长结构的方位角来调节反射光的偏转角度。针对本实施例，在亚波长结构的方位角一定的情况下，在确定投影到光控取向层的曝光场的出射光的出射角度后，可结合射线光学及广义的反射定律确定入射至线偏振光转换元件(超构表面)的线偏振入射光的入射角。由此可通过调整线偏振入射光的入射角实现对出射光出射角的调节，以实现对光控取向层的曝光场的曝光及对应液晶分子的取向。
需要说明的是，图1仅用于示例性的说明亚波长结构的排布情况，具体排布视实际情况而定。
另外，上述线偏振光转换元件可以通过对线偏振入射光的反射或透射实现对线偏振入射光偏振方向的调控，相应的，线偏振光转换元件中的超构表面可以为反射式超构表面或透射式超构表面。在一实施例中，针对反射式超构表面，超构表面/超构表面功能单元可包括金属反射层202、介质层203和金属亚波长 结构201的叠层结构(参考图2)，或者超构表面功能单元可包括金属反射层和金属亚波长结构的叠层结构，或者超构表面功能单元可包括金属反射层和介质亚波长结构的叠层结构；针对透射式超构表面，超构表面功能单元可包括介质亚波长结构。本申请实施例对超构表面/超构表面功能单元的具体膜层结构不作限制，具体可视实际情况而定。
基于上述实施例，本申请的另一实施例提供了一种线偏振光转换系统，如图3所示，该线偏振光转换系统10包括激光器101、光束整形器102、线偏振片103和上述实施例提供的线偏振光转换元件104。
其中，激光器101设置为提供激光光源；光束整形器102设置为对激光器101出射的激光进行整形；线偏振片103设置为将整形后的激光变换成线偏振入射光，并传播至线偏振光转换元件104的超构表面。
上述光束整形器102可以为高斯平顶光束转换器或者空间滤波准直系统。
在一实施例中，线偏振光转换系统10可以为液晶光控取向系统。此时，参考图3，由激光器101发射的激光经光束整形器102和线偏振片103后形成线偏振入射光入射至线偏振光转换元件104的超构表面，参考上述任一实施例提供的线偏振光转换元件104的作用，线偏振光转换元件104可将线偏振入射光转换成满足需求的线偏振分布状态的出射光，并将出射光投影至预先旋涂到导电玻璃衬底30上的光控取向层31，完成对光控取向层31的取向，从而实现对光控取向层31之间的液晶分子32的高分辨率空间排列分布。
本实施例所提供的线偏振光转换系统，包括本申请实施例所提供的线偏振光转换元件，具备相应的功能和有益效果。
另外，利用上述线偏振光转换系统制备的特殊的液晶光子学器件(如分束器)，也可通过制备的液晶光子学器件产生与调控特殊光场(如涡旋光束、贝塞尔光束和艾里光束等)。
在一实施例中，以通过本申请的线偏振光转换系统制备可产生与调控涡旋光束的液晶光子学器件为例进行说明。涡旋光束具有螺旋形的等相位面，每个光子具有
Figure PCTCN2019091154-appb-000004
的轨道角动量，其中m为拓扑量子数，可以是任意的整数，表示轨道角动量指数，不同的值对应相互正交的角动量状态，
Figure PCTCN2019091154-appb-000005
为约化普朗克常量。涡旋光束中心是相位奇点，该处振幅为零，因此呈现出环形的光场分布。涡旋光束 在光镊、光通讯、超分辨成像、以及天文观测等领域具有广泛的应用。
基于全息的原理，涡旋光束和参考光(如高斯光束，理想的平面波)有角度的干涉时会得到叉形干涉图样(如图4所示)。此时，待制备的液晶光子学器件中的液晶分子的取向分布应呈图4所示的叉形干涉图样进行排布，进而可基于该叉形干涉图样设计亚波长结构的排布图案(如图5所示)，然后利用具有图5所示的亚波长结构的超构表面定向液晶分子，可使液晶分子取向分布呈图4所示的叉形干涉图样，再用参考光照射即可产生涡旋光。
基于上述实施例，本申请又一实施例提供了一种线偏振光转换元件的制备方法，如图6所示，该线偏振光转换元件的制备方法包括：步骤110和步骤120。
在步骤110中，提供衬底。
其中，衬底1的材料可以为硅、玻璃、或ITO等透明材料。
在步骤120中，在衬底上形成超构表面。
其中，超构表面包括多个超构表面功能单元，超构表面功能单元包括各向异性的亚波长结构，亚波长结构基于线偏振入射光的偏振方向以及所需出射光的线偏振状态分布而排布。
在一实施例中，在衬底上形成超构表面可包括：根据所需出射光的线偏振状态分布，确定超构表面上亚波长结构在平面上的方位角分布，其中，方位角为亚波长结构的长轴方向与入射至线偏振光转换元件的线偏振入射光的偏振方向之间的夹角；根据线偏振入射光的偏振方向及方位角分布，确定亚波长结构的排布图案；基于亚波长结构的排布图案，在衬底上至少形成亚波长结构。
在一实施例中，基于亚波长结构的排布图案，在衬底上至少形成亚波长结构可包括：在衬底上蒸镀形成依次层叠的金属反射层和介质层；在介质层远离衬底一侧的表面旋涂光刻胶或电子束胶；光刻光刻胶或电子束胶，以去除部分光刻胶或电子束胶，并在去除的光刻胶或电子束胶处形成亚波长结构的排布图案；整面蒸镀一层金属；溶解剩余光刻胶或电子束胶，去除蒸镀于光刻胶或电子束胶上的金属，以使剩余金属形成亚波长结构。
基于上述技术方案，在本申请的一应用实施例中，如图7所示，线偏振光转换元件的制备方法包括：步骤210至步骤280。
在步骤210中，提供衬底。
在步骤220中，根据所需出射光的线偏振状态分布，确定超构表面上亚波 长结构在平面上的方位角分布。
其中，方位角为亚波长结构的长轴方向与入射至线偏振光转换元件的线偏振入射光的偏振方向之间的夹角。
根据所需出射光的线偏振状态分布，可确定超构表面上每个区域所出射光的偏振方向，由上述实施例中的贝里几何相位原理可知，出射光的偏振方向为亚波长结构的方位角的2倍，因此可确定超构表面上亚波长结构在平面上的方位角分布。
在步骤230中，根据线偏振入射光的偏振方向及方位角分布，确定亚波长结构的排布图案。
由于方位角为亚波长结构的长轴方向与入射至线偏振光转换元件的线偏振入射光的偏振方向之间的夹角，因此，在线偏振入射光的偏振方向一定的条件下，根据步骤220得到的方位角分布可确定超构表面上每个区域亚波长结构的长轴方向，进而确定亚波长结构的排布图案。
在步骤240中，在衬底上蒸镀形成依次层叠的金属反射层和介质层。
参考图8，在衬底1上蒸镀形成依次层叠的金属反射层202和介质层203。其中，金属反射层202的材料可以为铝或金，介质层203的材料可以为二氧化硅。在一实施例中，可采用热蒸镀或电子束蒸镀技术在衬底1上依次蒸镀金属反射层202和介质层203。
在步骤250中，在介质层远离衬底一侧的表面旋涂光刻胶或电子束胶。
如图9所示，在介质层203远离衬底1一侧的表面旋涂光刻胶40或电子束胶。
在步骤260中，光刻光刻胶或电子束胶，以去除部分光刻胶或电子束胶，并在去除的光刻胶或电子束胶处形成亚波长结构的排布图案。
在一实施例中，如图10所示，采用紫外光刻曝光光刻胶40，或者采用电子束光刻曝光电子束胶，再使用相应的显影液去除曝光的光刻胶40或电子束胶，以在去除的光刻胶40或电子束胶处形成亚波长结构的排布图案200，最后对剩余光刻胶40或电子束胶进行清洗。
在步骤270中，整面蒸镀一层金属。
在一实施例中，如图11所示，采用电子束蒸镀工艺或热蒸镀工艺在介质层203表面和剩余光刻胶40或电子束胶表面蒸镀一层金属50。
在步骤280中，溶解剩余光刻胶或电子束胶，去除蒸镀于光刻胶或电子束 胶上的金属，以使剩余金属形成亚波长结构。
在一实施例中，如图12所示，利用相应的去胶液去除剩余光刻胶40或电子束胶，使位于剩余光刻胶40或电子束胶上的金属随之脱落，进而保留介质层203表面的金属层，形成亚波长结构201。
通过上述线偏振光转换元件的制备方法，可制备具有反射式超构表面的线偏振光转换元件，上述实施例仅示例性的描述了具有金属反射层202、介质层203和金属亚波长结构201的反射式超构表面的制备方法，需要说明的是，本申请中线偏振光转换元件的反射式超构表面还可包括金属反射层和金属亚波长结构的叠层结构，或者金属反射层和介质亚波长结构的叠层结构，其具体制备方法可基于本实施例的线偏振光转换元件的制备方法合理性推出，此处不再赘述。
另外，本申请实施例还提供了一种具有透射式超构表面的线偏振光转换元件的制备方法，具体可包括如下步骤：步骤310至步骤390。
在步骤310中，提供透明的衬底。
在步骤320中，根据所需出射光的线偏振状态分布，确定超构表面上亚波长结构在平面上的方位角分布。
在步骤330中，根据线偏振入射光的偏振方向及方位角分布，确定亚波长结构的排布图案。
在步骤340中，在透明的衬底上蒸镀或沉积介质层。
其中，介质层的材料可以为硅、氮化硅或二氧化钛。
在步骤350中，在介质层远离衬底一侧的表面旋涂光刻胶或电子束胶。
在步骤360中，光刻光刻胶或电子束胶，以去除部分光刻胶或电子束胶，并在去除的光刻胶或电子束胶处形成亚波长结构的排布图案。
在步骤370中，整面蒸镀一层保护层。
其中，保护层的材料可以为铬。
在步骤380中，溶解剩余光刻胶或电子束胶，去除蒸镀于光刻胶或电子束胶上的保护层。
在步骤390中，以剩余保护层为掩膜，对没有覆盖保护层的介质层进行刻蚀，并去除剩余保护层，以使剩余介质层形成亚波长结构。
在一实施例中，所需出射光的线偏振状态分布由待取向液晶的取向方向确定。由此，可基于待取向液晶的取向方向确定所需出射光的线偏振状态分布，进而制备用于液晶光控取向的液晶光控取向系统，可在亚波长尺度控制液晶分 子取向，实现高空间分辨率的液晶光控取向。
另外，本申请还可基于表面等离激元共振原理，通过调整亚波长结构的参数(如长和宽)来提高超构表面的光学反射效率，进而提高线偏振入射光的利用率，减少线偏振入射光的损失。

Claims (10)

  1. 一种线偏振光转换元件，包括：
    衬底；
    超构表面，位于所述衬底上；
    其中，所述超构表面包括至少一个光场调控区，每个所述光场调控区包括至少一个超构表面功能单元，每个所述超构表面功能单元包括各向异性的亚波长结构，在同一所述光场调控区中，每个所述亚波长结构的长轴方向一致。
  2. 根据权利要求1所述的元件，其中，所述至少一个光场调控区包括至少两个光场调控区，不同的光场调控区中的所述亚波长结构的长轴方向不同。
  3. 根据权利要求1所述的元件，其中，所述超构表面功能单元包括以下任意一种：(i)金属反射层、介质层和金属亚波长结构的叠层结构，(ii)金属反射层和金属亚波长结构的叠层结构，(iii)金属反射层和介质亚波长结构的叠层结构，以及(iv)介质亚波长结构。
  4. 一种线偏振光转换系统，包括激光器、光束整形器、线偏振片和如权利要求1-3任一项所述的线偏振光转换元件；
    所述激光器设置为提供激光光源；所述光束整形器设置为对所述激光器出射的激光进行整形；所述线偏振片设置为将整形后的激光变换成线偏振入射光，并传播至所述线偏振光转换元件的超构表面。
  5. 根据权利要求4所述的系统，其中，所述线偏振光转换系统为液晶光控取向系统。
  6. 一种线偏振光转换元件的制备方法，包括：
    提供衬底；
    在所述衬底上形成超构表面，其中，所述超构表面包括多个超构表面功能单元，所述超构表面功能单元包括各向异性的亚波长结构，所述亚波长结构基于线偏振入射光的偏振方向以及所需出射光的线偏振状态分布而排布。
  7. 根据权利要求6所述的方法，其中，在所述衬底上形成超构表面，包括：
    根据所需出射光的线偏振状态分布，确定所述超构表面上所述亚波长结构在平面上的方位角分布，其中，方位角为所述亚波长结构的长轴方向与入射至所述线偏振光转换元件的线偏振入射光的偏振方向之间的夹角；
    根据线偏振入射光的偏振方向及所述方位角分布，确定所述亚波长结构的排布图案；
    基于所述亚波长结构的排布图案，在所述衬底上至少形成所述亚波长结构。
  8. 根据权利要求7所述的方法，其中，基于所述亚波长结构的排布图案，在所述衬底上至少形成所述亚波长结构，包括：
    在所述衬底上蒸镀形成依次层叠的金属反射层和介质层；
    在所述介质层远离所述衬底一侧的表面旋涂光刻胶或电子束胶；
    光刻所述光刻胶或所述电子束胶，以去除部分所述光刻胶或所述电子束胶，并在去除的所述光刻胶或所述电子束胶处形成所述亚波长结构的排布图案；
    整面蒸镀一层金属；
    溶解剩余所述光刻胶或所述电子束胶，去除蒸镀于所述光刻胶或所述电子束胶上的金属，以使剩余金属形成所述亚波长结构。
  9. 根据权利要求7所述的方法，其中，基于所述亚波长结构的排布图案，在所述衬底上至少形成所述亚波长结构，包括：
    在透明的衬底上蒸镀或沉积介质层；
    在所述介质层远离所述衬底一侧的表面旋涂光刻胶或电子束胶；
    光刻所述光刻胶或所述电子束胶，以去除部分所述光刻胶或所述电子束胶，并在去除的所述光刻胶或所述电子束胶处形成所述亚波长结构的排布图案；
    整面蒸镀一层保护层；
    溶解剩余所述光刻胶或所述电子束胶，去除蒸镀于所述光刻胶或所述电子束胶上的保护层；
    以剩余所述保护层为掩膜，对没有覆盖所述保护层的介质层进行刻蚀，并去除剩余所述保护层，以使剩余所述介质层形成所述亚波长结构。
  10. 根据权利要求6所述的方法，其中，所述所需出射光的线偏振状态分布由待取向液晶的取向方向确定。
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CN115236786B (zh) * 2022-08-02 2024-02-02 西北工业大学 一种液晶相位板、制备方法及双面涡旋光束产生系统
WO2024045150A1 (en) * 2022-09-02 2024-03-07 Huawei Technologies Co., Ltd. Devices and methods for controllably reflecting electromagnetic waves
CN115793326B (zh) * 2022-10-28 2025-08-08 南方科技大学 一种连续相位超构表面结构、空间光调制器以及制备方法
CN118519219A (zh) * 2023-02-20 2024-08-20 华为技术有限公司 一种显示器和显示设备
CN116300072B (zh) * 2023-03-17 2025-08-19 北京大学 一种自旋角动量和动量方向可控的单光子发射器及其方法
CN116931261A (zh) * 2023-08-14 2023-10-24 深圳迈塔兰斯科技有限公司 超透镜的设计方法、超透镜、整形合束装置及显示装置
CN118897408B (zh) * 2024-07-01 2025-11-21 福州大学 一种基于液晶调控的超构表面的仿生涉水色彩还原系统
CN119758507B (zh) * 2024-12-26 2025-11-04 南京大学 一种实现标量涡旋和矢量光束的微结构及其设计方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110134520A1 (en) * 2009-12-09 2011-06-09 Advanced Micro Devices, Inc. Optical isolation module and method for utilizing the same
CN103792605A (zh) * 2013-12-11 2014-05-14 南京大学 叉形液晶光栅的制备及其在生成涡旋光束中的应用
CN107272216A (zh) * 2017-08-01 2017-10-20 中国科学院半导体研究所 透射式金属超材料光束偏振分布变换器件
CN108490603A (zh) * 2018-03-09 2018-09-04 北京理工大学 基于透射型介质超颖表面产生矢量光束的方法
CN109581548A (zh) * 2019-01-04 2019-04-05 南方科技大学 一种线偏振光转换元件、制备方法和线偏振光转换系统

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4664865B2 (ja) * 2006-06-02 2011-04-06 株式会社リコー 光処理素子
CN102776566A (zh) * 2011-05-11 2012-11-14 深圳光启高等理工研究院 基于多晶硅的超材料制备方法和基于多晶硅的超材料
CN106066541B (zh) * 2016-07-27 2019-06-25 鲁东大学 一种产生广义柱面矢量偏振光束的方法及装置
CN106646715B (zh) * 2016-11-28 2019-03-08 南京大学 一种对称l形金属超构表面分束器以及制备方法
CN106842376B (zh) * 2017-01-25 2019-06-04 南京大学 一种三维超构材料及其制备方法和应用
CN107589540B (zh) * 2017-10-31 2020-09-25 重庆大学 双折射相位调控超表面结构单元、宽带偏振与相位调控阵列及器件
CN108646427B (zh) * 2018-05-16 2020-11-27 中国科学院光电技术研究所 一种基于超构表面的超薄衍射光学元件
CN108803088A (zh) * 2018-05-31 2018-11-13 上海理工大学 基于超表面的光偏振控制的透反射一体式转换器
CN109459870B (zh) * 2018-07-04 2020-04-24 北京理工大学 基于双折射介质超颖表面的多通道矢量全息偏振复用方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110134520A1 (en) * 2009-12-09 2011-06-09 Advanced Micro Devices, Inc. Optical isolation module and method for utilizing the same
CN103792605A (zh) * 2013-12-11 2014-05-14 南京大学 叉形液晶光栅的制备及其在生成涡旋光束中的应用
CN107272216A (zh) * 2017-08-01 2017-10-20 中国科学院半导体研究所 透射式金属超材料光束偏振分布变换器件
CN108490603A (zh) * 2018-03-09 2018-09-04 北京理工大学 基于透射型介质超颖表面产生矢量光束的方法
CN109581548A (zh) * 2019-01-04 2019-04-05 南方科技大学 一种线偏振光转换元件、制备方法和线偏振光转换系统

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113608281A (zh) * 2021-06-25 2021-11-05 中山大学 一种具有相位和振幅调控能力的反射式动态超构表面器件
CN113608281B (zh) * 2021-06-25 2022-09-30 中山大学 一种具有相位和振幅调控能力的反射式动态超构表面器件
CN113820895A (zh) * 2021-07-08 2021-12-21 湖南大学 一种基于超构表面的像素化动态全息显示器件及实现方法
CN113917588A (zh) * 2021-09-06 2022-01-11 武汉理工大学 超表面结构透射式偏振调控器及其制备方法
CN113917588B (zh) * 2021-09-06 2022-07-05 武汉理工大学 超表面结构透射式偏振调控器及其制备方法
CN113917580A (zh) * 2021-09-13 2022-01-11 华中科技大学 一种白光超表面角谱微分器及角谱微分方法
CN113917580B (zh) * 2021-09-13 2022-05-31 华中科技大学 一种白光超表面角谱微分器及角谱微分方法
CN114336075A (zh) * 2022-01-10 2022-04-12 安徽师范大学 一种涡旋电磁超表面结构及其涡旋电磁波产生方法
CN114336075B (zh) * 2022-01-10 2022-11-22 安徽师范大学 一种涡旋电磁超表面结构及其涡旋电磁波产生方法

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