CN111897164B - Liquid crystal type radial polarized light converter and preparation method thereof - Google Patents

Abstract

The invention provides a liquid crystal type radial polarized light converter and a preparation method thereof, wherein the converter comprises a first substrate and a second substrate which are arranged in parallel and at intervals; the patterning cofferdam layer is arranged on the surface of the first substrate facing the second substrate and provided with a circular cofferdam hole; the liquid crystal parallel alignment layer is arranged on the surface of the second substrate close to the first substrate; the liquid crystal layer is formed in a preset gap between the patterned cofferdam layer and the liquid crystal parallel arrangement alignment layer and the circular cofferdam hole, wherein liquid crystal molecules are radially distributed in the circular cofferdam hole, the liquid crystal molecules are parallelly arranged on the surface of the liquid crystal parallel arrangement alignment layer, and the liquid crystal molecules are twisted and radially arranged between the patterned cofferdam layer and the liquid crystal parallel arrangement alignment layer. The liquid crystal type radial polarized light converter can convert linear polarized light passing through the converter into radial polarized light, has simple structure, convenient operation and application and simple and easy preparation process, and can realize array production.

Description

Liquid crystal type radially polarized light converter and preparation method thereof

technical field

The invention relates to the technical field of liquid crystal optoelectronics, in particular to a liquid crystal type radially polarized light converter and a preparation method thereof.

Background technique

In addition to the common linear polarization, circular polarization, and elliptical polarization, the beam polarization state also includes radial polarization state and azimuthal polarization state. Radially polarized light is widely used in particle trapping, optical micromanipulation, optical information storage, light-matter interaction, electronic Acceleration, microscopy systems, lithography, laser processing, optical tweezers technology, super-resolution fields, etc.

Liquid crystal has optical anisotropy and is an excellent material for preparing polarized light converters. In the liquid crystal polarization converter, the liquid crystal molecules need to form radial alignment on one of the substrates. For example, various methods such as electric field-induced alignment of liquid crystal molecules, light-controlled alignment, and circular rubbing treatment can be used to realize the radial alignment of liquid crystal molecules, but these methods can only obtain a single liquid crystal polarized light converter, and the preparation process is cumbersome and difficult to achieve. Array production. The liquid crystal polarization converter array can realize simultaneous processing of multiple beams of light, and a single liquid crystal polarization converter is in the micrometer scale.

SUMMARY OF THE INVENTION

In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a liquid crystal type radially polarized light converter and a preparation method thereof, which are used to solve the problem that the existing radially polarized light beam generating device has high production cost and complicated operation. , the beam generation process is cumbersome, affects the work efficiency and is difficult to array the technical problems.

In order to achieve the above purpose and other related purposes, the present invention provides a liquid crystal type radially polarized light converter, and the liquid crystal type radially polarized light converter includes:

a first substrate;

a second substrate, arranged in parallel and at intervals on one side of the first substrate;

a patterned dam layer, disposed on the surface of the first substrate facing the second substrate, the patterned dam layer has at least one circular dam hole penetrating the patterned dam layer;

The liquid crystal parallel alignment layer is disposed on the surface of the second substrate close to the first substrate, and a predetermined gap is reserved between the liquid crystal parallel alignment layer and the patterned bank layer;

a liquid crystal layer, formed in a predetermined gap between the patterned bank layer and the liquid crystal parallel alignment layer and in the circular bank hole;

The liquid crystal molecules are radially distributed in the circular bank hole, the liquid crystal molecules are arranged in parallel on the surface of the liquid crystal parallel alignment layer, and the liquid crystal molecules are arranged in parallel with the liquid crystal in the patterned bank layer. The alignment layers are twisted-radially arranged.

In an optional embodiment, the diameter of the circular cofferdam hole is between 10 μm and 2000 μm.

In an optional embodiment, the thickness of the patterned bank layer is between 5 nm and 1 μm.

In an optional embodiment, the material of the patterned bank layer includes perfluoro(1-butenyl vinyl ether), polytetrafluoroethylene, polydimethylsiloxane, octadecyl trichloride Silane or polyimide.

In an optional embodiment, the liquid crystal parallel alignment layer includes a polyimide or azobisphenyl liquid crystal photoalignment agent treated with parallel rubbing.

In an optional embodiment, the preset gap is between 5 μm and 100 μm.

In an optional embodiment, the liquid crystal type radially polarized light converter further comprises a spacer for controlling the distance between the first substrate and the second substrate and located between the first substrate and the second substrate. spacer particles or polyester spacer films.

In an optional embodiment, the patterned bank layer has a bank hole array comprising a plurality of the circular bank holes.

In an optional embodiment, the distance between two adjacent circular cofferdam holes in the circular cofferdam hole array is greater than 3 μm.

In order to achieve the above purpose and other related purposes, the present invention also provides a preparation method of a liquid crystal type radially polarized light converter, the preparation method comprising:

A first substrate is provided, and a patterned dam layer is formed on the surface of the first substrate, the patterned dam layer has at least one circular dam hole penetrating the patterned dam layer;

coating liquid crystal on the patterned dam layer to form liquid crystal droplets in the circular dam hole;

a second substrate is provided, and a liquid crystal parallel alignment layer is formed on the surface of the second substrate;

The first substrate and the second substrate are laminated and sealed, and the liquid crystal parallel alignment layer and the patterned dam layer are arranged opposite to each other and a preset gap is reserved to form a liquid crystal radially polarized light converter;

Wherein, the liquid crystal droplets are spread out and arranged in the predetermined gap between the patterned bank layer and the liquid crystal parallel alignment layer and the circular bank hole during the substrate bonding and sealing process. The liquid crystal molecules are radially distributed in the circular bank hole, the liquid crystal molecules are arranged in parallel on the surface of the liquid crystal parallel alignment layer, and the liquid crystal molecules are arranged in parallel with the liquid crystal in the patterned bank layer. The alignment layers are twisted-radially arranged.

In an optional embodiment, the step of forming a patterned bank layer on the surface of the first substrate includes:

forming a photoresist layer on the surface of the first substrate;

exposing, developing and post-baking the photoresist layer to form a patterned photoresist layer, the patterned photoresist layer comprising at least one cylindrical protrusion;

forming a dam material layer on the surface of the first substrate on which the patterned photoresist layer is formed;

removing the patterned photoresist layer and the dam material layer on the patterned photoresist layer to form a patterned dam layer on the surface of the first substrate, the patterned dam layer having at least one A circular cofferdam hole penetrates the patterned cofferdam layer, wherein the circular cofferdam hole corresponds to the position of the circular raised portion.

The present invention utilizes the optoelectronic properties of liquid crystal to coat the liquid crystal on the upper substrate modified by the cofferdam layer (having an array of cofferdam holes), the liquid crystal molecules are arranged radially in the circular cofferdam holes of the cofferdam layer, and the lower substrate is coated with The alignment layer makes the liquid crystal molecules arranged in parallel, and the upper and lower substrates form a liquid crystal cell, so that the liquid crystal molecules are arranged in a twist-radial arrangement, thereby preparing a twist-radial arrangement of liquid crystal radially polarized light converters. When the linearly polarized light passes through the liquid crystal When the type radially polarized light converter is used, it will be converted into a radially polarized light array;

The liquid crystal type radially polarized light converter of the invention has the advantages of simple structure, convenient operation, convenient application, simple and easy preparation process, and easy arraying, and can solve the problem that the existing radially polarized beam generating device has high manufacturing cost, complicated operation, and beam The problem is that the process is cumbersome, affects work efficiency and is difficult to array.

Description of drawings

FIG. 1 is a schematic diagram showing the structure of the liquid crystal radially polarized light converter of the present invention.

FIG. 2 is a schematic diagram showing the arrangement of liquid crystal molecules along the YOZ section in FIG. 1 .

FIG. 3 is a schematic diagram showing the arrangement of liquid crystal molecules along the XOZ section in FIG. 1 .

FIG. 4 is a schematic diagram showing the liquid crystal type radially polarized light converter of the present invention converting linearly polarized light into radially polarized light.

FIG. 5 is a flow chart showing the preparation of the liquid crystal radially polarized light converter of the present invention.

FIG. 6 is a schematic diagram illustrating the formation of a photoresist layer on the upper substrate during the preparation process of the liquid crystal radially polarized light converter of the present invention.

FIG. 7 is a schematic diagram showing the ultraviolet exposure of the photoresist layer during the preparation process of the liquid crystal radially polarized light converter of the present invention.

FIG. 8 is a schematic diagram of developing the exposed photoresist layer to obtain a patterned photoresist layer during the preparation process of the liquid crystal radially polarized light converter of the present invention.

FIG. 9 shows that the surface of the patterned photoresist layer is coated with perfluoro(1-butenyl vinyl ether)/perfluorotributylamine during the preparation process of the liquid crystal radially polarized light converter of the present invention Schematic of the solution.

FIG. 10 is a schematic diagram showing the volatilization of the solvent perfluorotributylamine in the perfluoro(1-butenyl vinyl ether) solution by heating during the preparation of the liquid crystal type radially polarized light converter of the present invention.

11 shows the removal of the patterned photoresist layer and the dam material layer on the patterned photoresist layer during the preparation process of the liquid crystal radially polarized light converter of the present invention, so that the upper substrate can be Schematic diagram of the patterned dam layer formed on the surface.

In the accompanying drawings, the list of components represented by each number is as follows:

1-lower substrate, 2-liquid crystal parallel alignment layer, 3-liquid crystal layer, 4-patterned bank layer, 5-upper substrate, 6-circular bank hole, 7-linearly polarized light, 8-liquid crystal diameter Polarized light converter, 9-polarizer, 10-light and dark alternating fan pattern, 11-hydrophobic, 12-mask, 13-ultraviolet, 14-patterned photoresist layer, 15-CYTOP hydrophobic solution, 16-solvent volatilize.

Detailed ways

The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to FIG. 1 to FIG. 11. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have The particular orientation, construction and operation in the particular orientation are therefore not to be construed as limitations of the invention.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

1-3, the embodiment of the present invention introduces a liquid crystal type radially polarized light converter 8, the liquid crystal type radially polarized light converter 8 includes an upper substrate 5 (first substrate), The liquid crystal cell composed of the lower substrate 1 (the second substrate) and the liquid crystal layer 3 disposed in the liquid crystal cell, the liquid crystal has optical anisotropy and is an excellent material for preparing a polarized light converter. 1 is a schematic structural diagram of a liquid crystal radially polarized light converter 8, FIG. 2 is a schematic diagram of the arrangement of liquid crystal molecules along the YOZ cross-section in FIG. 1, and FIG. 3 is a schematic diagram of the liquid crystal molecular arrangement along the XOZ cross-section in FIG. 1 A schematic diagram of the situation, wherein the Z direction refers to the direction from the upper substrate 5 to the lower substrate 1, the Y direction refers to the rubbing direction of the liquid crystal parallel alignment layer 2 to be described later, and the X direction is perpendicular to the Y direction.

Referring to FIGS. 1-3 , in this embodiment, the upper substrate 5 may be, for example, a glass substrate, and a patterned dam layer 4 is formed on the surface of the upper substrate 5 facing the lower substrate 1 . The formation method of the patterned cofferdam layer 4 is detailed in the preparation process below, which will not be repeated here. The patterned cofferdam layer 4 includes a cofferdam hole array composed of a plurality of circular cofferdam holes 6 penetrating the patterned cofferdam layer 4 , and FIG. It can be understood that the number of circular cofferdam holes 6 in the cofferdam hole array can be adjusted as required, and the number of the circular cofferdam holes 6 can be, for example, 1, 2, 3 or more than 4 . Because the material of the patterned bank layer 4 is selected from the material that liquid crystal molecules can be vertically aligned on the surface, such as perfluoro(1-butenyl vinyl ether), polytetrafluoroethylene, polydimethylsiloxane, Octadecyltrichlorosilane, polyimide vertical alignment agent and other materials, such as perfluoro(1-butenyl vinyl ether) perfluorotributylamine solution, perfluoro(1-butenyl vinyl ether) ) and perfluorotributylamine in a volume ratio of 1:5-40, such as 1:5, 1:10, 1:20, 1:30..., so that the circular cofferdam hole 6 can be located inside it The liquid crystal molecules are radially distributed. As an example, the diameter of the circular cofferdam hole 6 is between 10 μm and 2000 μm, such as 10 μm, 100 μm, 300 μm, 500 μm, 700 μm, 900 μm, 1100 μm, 1500 μm or 2000 μm. The weir hole 6 can also take other suitable values between 10 μm and 2000 μm. As an example, in the array of circular cofferdam holes 6, the distance between two adjacent circular cofferdam holes 6 is greater than 3 μm, such as 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, . . . It can be understood that Yes, the distance between two adjacent circular cofferdam holes 6 can be adjusted as required, and is not limited to the above-mentioned values. As an example, the thickness of the patterned bank layer 4 is between 5 nm and 1 μm, such as 10 nm, 30 nm, 50 nm, 70 nm, 90 nm, 110 nm, 300 nm, 500 nm, 700 nm or 900 nm, it is understood that the pattern The thickness of the chemical bank layer 4 may also take other suitable values between 5 nm and 1 μm.

Referring to FIGS. 1-3 , in this embodiment, the lower substrate 1 may be, for example, a glass substrate, and a surface of the lower substrate 1 close to the upper substrate 5 is provided with a liquid crystal parallel arrangement for aligning liquid crystal molecules in parallel Alignment layer 2, the liquid crystal parallel alignment alignment layer 2 may be a polyimide alignment layer treated by parallel rubbing, and the formation method of the liquid crystal parallel alignment alignment layer 2 is detailed in the preparation process below, which will not be repeated here. It can be understood that, in some embodiments, the liquid crystal parallel alignment layer 2 may also be a light control liquid crystal alignment layer.

1-3, in this embodiment, the liquid crystal layer 3 is formed at a predetermined gap between the patterned bank layer 4 and the liquid crystal parallel alignment layer 2 and the circular bank in hole 6. For example, a blade coating method (of course, a spin coating method or a pulling method) can be used to coat the liquid crystal (the liquid crystal can be pure liquid crystal, or a mixture of liquid crystal and polymer monomer) on the patterned pattern. On the bank layer 4 , the liquid crystal will remain in each circular bank hole 6 of the patterned bank layer 4 to form an array of liquid crystal droplets whose tops are higher than the patterned bank layer 4 Then control the thickness of the liquid crystal cell, and attach and seal the upper substrate 5 and the lower substrate 1, so that the liquid crystal parallel alignment layer 2 and the patterned bank layer 4 are oppositely arranged and reserved There is a preset gap. It should be noted that, in the process of laminating the substrates, the liquid crystal droplets will be spread out in a direction parallel to the substrate and arranged in all areas between the patterned bank layer 4 and the liquid crystal parallel alignment layer 2 . The predetermined gap and the circular bank hole 6 are formed to form the liquid crystal layer 3 .

Referring to FIGS. 1-3 , in this embodiment, the liquid crystal molecules are arranged in parallel along the Y direction on the surface of the liquid crystal parallel alignment layer 2 , and the liquid crystal molecules are arranged in a radial direction in the circular bank hole 6 distribution, so that the liquid crystal molecules between the patterned dam layer 4 and the liquid crystal parallel alignment layer 2 are in a twist-radial alignment, and the liquid crystal molecules are consistent on the YOZ plane and are arranged in the Y direction. (see Figure 2), and the liquid crystal molecules gradually transition from parallel to the Y direction to parallel to the X direction on the XOZ plane (see Figure 3), thereby forming a liquid crystal polarized light conversion at the corresponding position of each circular bank hole 6 The unit, that is, each of the liquid crystal type radial polarization converters 8 is an array of liquid crystal polarization conversion units composed of several (four are shown in FIG. 1 ) liquid crystal polarization conversion units. FIG. 4 shows the principle of converting the linearly polarized light into radially polarized light by the liquid crystal type radially polarized light converter 8 in this embodiment, and the liquid crystal type radially polarized light converter 8 is placed between orthogonal polarizers When passing through the liquid crystal radially polarized light converter 8 and the analyzer (polarizer 9), the linearly polarized light 7 is radially polarized by the conversion layer.

It should be noted that, in order to control the thickness of the liquid crystal cell, the liquid crystal radially polarized light converter 8 further includes a polyester spacer film (of course) for controlling the distance between the upper substrate 5 and the lower substrate 1 Spacer particles can also be used), the polyester spacer film is disposed between the patterned bank layer 4 and the liquid crystal parallel alignment layer 2, the thickness of the polyester spacer film (that is, the preset The thickness of the gap) is between 5 μm and 100 μm, such as 5 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 50 μm or 80 μm. The thickness of the polyester spacer film can be determined according to the Morgan condition, that is, formula (1):

为液晶分子总扭曲角度，d为液晶层厚度，Δn为双折射，也就是光学各向异性(即Δn＝n_e-n_o，n_e为非寻常光的折射率，n_o为寻常光的折射率)，λ为波长；in,

is the total twist angle of the liquid crystal molecules, d is the thickness of the liquid crystal layer, Δn is the birefringence, that is, the optical anisotropy (that is, Δn= _{ne -no} , ne is the refractive index of extraordinary light, and _{n o is} the refractive index of ordinary light refractive index), λ is the wavelength;

公式(1)可简化为公式(2)：For a twist-nematic liquid crystal cell with a twist of 90°

Equation (1) can be simplified to Equation (2):

d＞＞λ/4Δn (2)

Referring to FIG. 5 , this embodiment also introduces a method for manufacturing the above-mentioned liquid crystal radially polarized light converter 8 , wherein FIG. 5 shows a schematic flowchart of the manufacturing method of the liquid crystal radially polarized light converter 8 . Please refer to FIG. 5 , the preparation method includes: step S10 , providing a first substrate, and forming a patterned dam layer 4 on the surface of the first substrate, the patterned dam layer 4 having at least a circular cofferdam hole 6 running through the patterned cofferdam layer 4; step S20, coating liquid crystal on the patterned cofferdam layer 4 to form liquid crystal droplets in the circular cofferdam hole 6; Step S30, providing a second substrate, and forming a liquid crystal parallel alignment layer 2 on the surface of the second substrate; Step S40, laminating and sealing the first substrate and the second substrate, the liquid crystal The parallel alignment layer 2 is disposed opposite the patterned dam layer 4 with a preset gap reserved, and the liquid crystal droplets are spread and arranged on the patterned dam layer 4 and the patterned dam layer 4 during the lamination and sealing process. The liquid crystals are arranged in parallel in the predetermined gaps between the alignment layers 2 and in the circular bank holes 6 to form the liquid crystal layer 3 .

Please refer to Fig. 6-11, step S10 further includes the following steps:

In step S11, an upper substrate 5 is provided, and photoresist is coated on the surface of the upper substrate 5, and the upper substrate 5 can be, for example, a glass substrate with a size of 2 cm×2 cm; step S12, the upper substrate coated with photoresist is applied. The substrate 5 is subjected to pre-baking treatment to form a photoresist layer 11 on the surface of the upper substrate 5. By controlling the temperature and the pre-baking time, the solvent in the photoresist can be volatilized and removed as much as possible to improve the photoresist layer. (see FIG. 6 ); step S13 , using ultraviolet light 13 to irradiate the upper substrate 5 with the photoresist layer 11 through the mask to expose the upper substrate 5 (see FIG. 7 ); step S14 , to The exposed photoresist layer 11 is developed to form a patterned photoresist layer 14 on the surface of the upper substrate 5, and the patterned photoresist layer 14 includes a plurality of circular protrusions ( FIG. 8 ). In step S15, the upper substrate 5 on which the patterned photoresist layer 14 is formed is subjected to post-baking treatment, and the temperature is controlled by controlling the temperature of the upper substrate 5. and post-baking time, evaporate the remaining solvent in the patterned photoresist layer 14 to harden the patterned photoresist layer 14 (corresponding to FIG. 8 ); step S16 , coat the surface of the patterned photoresist layer 14 Perfluoro(1-butenyl vinyl ether) perfluorotributylamine solution 15 (of course, it can also be polytetrafluoroethylene solution, polydimethylsiloxane solution, octadecyltrichlorosilane solution, poly Imide and other vertical alignment agent solutions, in the perfluoro(1-butenyl vinyl ether) hydrophobic solution 15, the volume ratio of perfluoro(1-butenyl vinyl ether) to the solvent perfluorotributylamine is 1:20 (corresponding to Figure 9), for example, it can be heated at 180°C for 10 minutes to volatilize the solvent perfluorotributylamine in the perfluoro(1-butenyl vinyl ether)/perfluorotributylamine hydrophobic layer solution 15 16, to form a dam material layer on the surface of the upper substrate 5 on which the patterned photoresist layer 14 is formed, it is understood that the heating temperature and time can be adjusted according to the actual situation (corresponding to FIG. 10 ); Step S17, using a special solvent to remove the remaining photoresist (ie, the patterned photoresist layer), during this process, the dam material layer on the patterned photoresist layer 14 is also removed at the same time, so that the A patterned dam layer 4 is formed on the surface of the upper substrate 5 , and the patterned dam layer 4 includes a dam hole array composed of a plurality of circular dam holes 6 penetrating the patterned dam layer 4 (step S17 ) 11 ). As an example, the diameter of the circular cofferdam hole 6 is between 10 μm and 2000 μm, such as 10 μm, 100 μm, 300 μm, 500 μm, 700 μm, 900 μm, 1100 μm, 1500 μm or 2000 μm, it can be understood that , the circular cofferdam hole 6 can also take other suitable values between 10 μm and 2000 μm. As an example, in the cofferdam hole array, the distance between two adjacent circular cofferdam holes 6 is greater than 3 μm, For example, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, ..., can be It should be understood that the distance between two adjacent circular cofferdam holes 6 can be adjusted as required, and is not limited to the above-mentioned values. As an example, the thickness of the patterned bank layer 4 is between 5 nm and 1 μm, such as 10 nm, 30 nm, 50 nm, 70 nm, 90 nm, 110 nm, 300 nm, 500 nm, 700 nm or 900 nm, it is understood that the pattern The thickness of the chemical bank layer 4 may also take other suitable values between 5 nm and 1 μm. It should be noted that although FIG. 11 shows a situation where four circular cofferdam holes 6 are included, it can be understood that the number of circular cofferdam holes 6 in the cofferdam hole array can be as required. For adjustment, the number may be 1, 2, 3, or more than 4, for example.

In step S20, the liquid crystal (the liquid crystal can be pure liquid crystal E7, or a mixture of liquid crystal and polymer monomer) can be coated by, for example, a blade coating method (of course it can also be a spin coating method or a pulling method). On the patterned bank layer 4, the liquid crystal will remain in each circular bank hole 6 of the patterned bank layer 4 to form an array of liquid crystal droplets, each liquid crystal droplet is formed in a circular bank in the hole 6 , and the top of the liquid crystal droplet is higher than the surface of the patterned bank layer 4 . Because the material of the patterned bank layer 4 is selected from the material that liquid crystal molecules can be vertically aligned on its surface, such as perfluoro(1-butenyl vinyl ether), polytetrafluoroethylene, polydimethylsiloxane alkane, octadecyltrichlorosilane, polyimide vertical alignment agent and other materials, such as perfluoro(1-butenyl vinyl ether), so that the circular bank hole 6 can make the liquid crystal inside it The molecules are distributed radially.

In step S30, the liquid crystal parallel alignment alignment layer 2 may be a polyimide alignment layer subjected to parallel rubbing treatment, and the polyimide alignment layer enables liquid crystal molecules to be arranged on the lower substrate 1 (polyimide alignment layer). The surfaces of the alignment layer) are arranged in parallel. The preparation process of the polyimide alignment layer includes: first, coating the surface of the lower substrate 1 with a polyimide solution (consisting of polyimide and N-methylpyrrolidone with a volume ratio of 1:10); then , heated at 220°C for 2 hours to volatilize the solvent in the polyimide solution, so as to form a polyimide layer on the surface of the lower substrate 1; A polyimide alignment layer is formed on the surface of the lower substrate 1 . It can be understood that, in some embodiments, the liquid crystal parallel alignment layer 2 may also be a light control liquid crystal alignment layer.

In step S40, the thickness of the liquid crystal cell (composed of the oppositely arranged upper substrate 5 and lower substrate 1) is controlled, and the upper substrate 5 and the lower substrate 1 are attached and sealed to form the structure shown in Figs. 1-3. The liquid crystal type radially polarized light converter 8, wherein the liquid crystal parallel alignment layer 2 and the patterned dam layer 4 are arranged opposite to each other and a preset gap is reserved. The thickness of the ester spacer film is limited. It should be noted that, in the process of laminating the substrates, the liquid crystal droplets will be spread out in a direction parallel to the substrate and arranged in all areas between the patterned bank layer 4 and the liquid crystal parallel alignment layer 2 . The predetermined gap and the circular bank hole 6 are formed to form the liquid crystal layer 3 .

In step S40, for example, the thickness of the liquid crystal cell can be controlled by arranging a polyester spacer film between the upper substrate 5 and the lower substrate 1 to control the distance between the two. Between the patterned bank layer 4 and the liquid crystal parallel alignment layer 2, the thickness of the polyester spacer film (that is, the thickness of the preset gap) is between 5 μm and 100 μm, such as 5 μm, 10 μm , 12 μm, 15 μm, 18 μm, 20 μm, 50 μm or 80 μm, it can be understood that the thickness of the polyester spacer film can also be other suitable values.

1-3, in the formed liquid crystal type radially polarized light converter 8, the liquid crystal molecules are arranged in parallel along the Y direction on the surface of the liquid crystal parallel alignment layer 2, and the liquid crystal molecules are arranged in the circular The cofferdam holes 6 are radially distributed, so that the liquid crystal molecules between the patterned cofferdam layer 4 and the liquid crystal parallel alignment layer 2 are in a twist-radial alignment, and the liquid crystal molecules remain on the YOZ plane. Consistent, all are arranged along the Y direction (see Figure 2), and the liquid crystal molecules gradually transition from parallel to the Y direction to parallel to the X direction (see Figure 3) on the XOZ plane, so that each circular cofferdam hole 6 corresponds to A liquid crystal polarized light conversion unit is formed at the position, that is, each of the liquid crystal type radial polarized light converters 8 is a liquid crystal polarized light conversion unit composed of several (four are shown in FIG. 1 ) liquid crystal polarized light conversion units. The unit array, when linearly polarized light is transmitted through the liquid crystal polarized light converting unit array, will be converted into a radially polarized light array.

After the preparation of the liquid crystal radially polarized light converter 8 is completed, a step of verifying the liquid crystal radially polarized light converter 8 is also included by means of a crossed polarized light microscope. Specifically, referring to FIG. 4 , the liquid crystal polarized light converter 8 of the present embodiment is placed on the stage of the crossed polarized light microscope, and when the linearly polarized incident light (linearly polarized light 7 ) is irradiated through the lower substrate 1 The liquid crystal type polarization converter 8, and the polarization direction of the incident light is parallel to the rubbing direction of the liquid crystal parallel alignment layer 2 of the lower substrate 1, and a fan-shaped pattern array 10 with alternating light and dark can be observed, indicating that the device can convert linearly polarized light. is a radially polarized light array.

To sum up, in this embodiment, using the optoelectronic properties of liquid crystal, the liquid crystal is coated on the upper substrate modified by the cofferdam layer (with the cofferdam hole array), and the liquid crystal molecules are in the circular cofferdam holes of the cofferdam layer. In radial arrangement, the lower substrate is coated with an alignment layer to make the liquid crystal molecules align in parallel, and the upper and lower substrates form a liquid crystal cell so that the liquid crystal molecules are arranged in a twist-radial arrangement, thereby preparing a twist-radial arrangement of liquid crystal radially polarized light converters. When the linearly polarized light is transmitted through the liquid crystal type radially polarized light converter, it will be converted into a radially polarized light array. The device has simple structure, convenient operation, convenient application, simple and easy preparation process, and is easy to be arrayed.

In the description herein, numerous specific details are provided, such as examples of components and/or methods, in order to provide a thorough understanding of embodiments of the present invention. However, one skilled in the art will recognize that embodiments of the invention may be practiced without one or more of the specific details or with other devices, systems, assemblies, methods, components, materials, parts, and the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of the embodiments of the invention.

The above description of illustrated embodiments of the present invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise form disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the invention, as those skilled in the art will recognize and appreciate of. As indicated, these modifications may be made to the present invention in light of the foregoing description of the described embodiments of the present invention and are intended to be within the spirit and scope of the present invention.

The systems and methods have generally been described herein with details that are helpful in understanding the invention. Furthermore, various specific details have been set forth in order to provide a general understanding of embodiments of the present invention. One skilled in the relevant art will recognize, however, that embodiments of the invention may be practiced without one or more of the specific details, or with other devices, systems, accessories, methods, components, materials, parts, etc. practice. In other instances, well-known structures, materials and/or operations have not been specifically shown or described in detail to avoid obscuring aspects of the embodiments of the invention.

Thus, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are intended to be within the above disclosure, and it should be understood that, in certain circumstances, without departing from the scope and scope of the proposed invention, Some features of the present invention will be employed without the corresponding use of other features in the spirit of the present invention. Therefore, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the invention. It is not intended that the invention be limited to the specific terms used in the following claims and/or the specific embodiments disclosed as the best modes contemplated for carrying out the invention, but the invention is to be included within the scope of the appended claims any and all embodiments and equivalents within. Accordingly, the scope of the present invention should be determined only by the appended claims.

Claims (10)

1. A liquid crystal-form radial polarized light converter, comprising:

a first substrate;

the second substrate is arranged on one side of the first substrate in parallel at intervals;

the patterning cofferdam layer is arranged on the surface of the first substrate, facing the second substrate, and is provided with at least one circular cofferdam hole which penetrates through the patterning cofferdam layer and exposes the surface of the first substrate;

the liquid crystal parallel arrangement alignment layer is arranged on the surface, close to the first substrate, of the second substrate, and a preset gap is reserved between the liquid crystal parallel arrangement alignment layer and the patterned cofferdam layer;

the liquid crystal layer is formed in a preset gap between the patterned cofferdam layer and the liquid crystal parallel arrangement alignment layer and the circular cofferdam hole;

the liquid crystal molecules are distributed in the circular cofferdam holes in a radial direction, the liquid crystal molecules are arranged on the surface of the liquid crystal parallel arrangement alignment layer in a parallel manner, and the liquid crystal molecules are arranged between the patterned cofferdam layer and the liquid crystal parallel arrangement alignment layer in a twisting-radial direction.

2. A liquid crystal-type radial polarization light converter according to claim 1, wherein the diameter of the circular weir aperture is between 10-2000 μ ι η.

3. A liquid crystal-type radial polarization light converter according to claim 1, wherein the thickness of the patterned bank layer is between 5nm-1 μm.

4. A liquid crystal-type radial polarization light converter according to claim 1, wherein the material of the patterned bank layer comprises perfluoro (1-butenyl vinyl ether) polymer, teflon, polydimethylsiloxane, or polyimide homeotropic alignment agent.

5. The liquid crystal-type radial polarization light converter of claim 1, wherein the liquid crystal parallel alignment layer comprises a parallel rubbed polyimide alignment layer or a light-operated liquid crystal alignment layer.

6. A liquid crystal-type radial polarization light converter according to claim 1, wherein the predetermined gap is between 10 μ ι η -20 μ ι η.

7. The liquid crystal-type radial polarization light converter of claim 1, further comprising a spacer or a polyester spacer film for controlling a spacing between the first substrate and the second substrate.

8. A liquid crystal-type radially polarized light converter according to any of claims 1-7, wherein said patterned bank layer has an array of bank holes comprising a plurality of said circular bank holes.

9. A preparation method of a liquid crystal type radial polarized light converter is characterized by comprising the following steps:

providing a first substrate, and forming a patterned cofferdam layer on the surface of the first substrate, wherein the patterned cofferdam layer is provided with at least one circular cofferdam hole which penetrates through the patterned cofferdam layer and exposes the surface of the first substrate;

coating liquid crystal on the patterned cofferdam layer to form liquid crystal microdroplets in the circular cofferdam holes;

providing a second substrate, and forming a liquid crystal parallel alignment layer on the surface of the second substrate;

the first substrate and the second substrate are attached and sealed, the liquid crystal parallel arrangement alignment layer and the patterned cofferdam layer are arranged oppositely, and a preset gap is reserved to form a liquid crystal type radial polarized light converter;

the liquid crystal droplets are unfolded and arranged in the preset gap between the patterned cofferdam layer and the liquid crystal parallel arrangement alignment layer and the circular cofferdam hole in the process of laminating and sealing the substrate, liquid crystal molecules are radially distributed in the circular cofferdam hole, the liquid crystal molecules are parallelly arranged on the surface of the liquid crystal parallel arrangement alignment layer, and the liquid crystal molecules are twisted-radially arranged between the patterned cofferdam layer and the liquid crystal parallel arrangement alignment layer.

10. The method of claim 9, wherein the step of forming a patterned bank layer on the surface of the first substrate comprises:

forming a photoresist layer on the surface of the first substrate;

carrying out exposure, development and post-baking treatment on the photoresist layer to form a patterned photoresist layer, wherein the patterned photoresist layer comprises at least one circular convex part;

forming a cofferdam material layer on the surface of the first substrate with the patterned photoresist layer;

and removing the cofferdam material layer on the patterned photoresist layer so as to form a patterned cofferdam layer on the surface of the first substrate, wherein the patterned cofferdam layer is provided with at least one circular cofferdam hole penetrating through the patterned cofferdam layer, and the circular cofferdam hole corresponds to the position of the circular bulge.

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