Planar large-angle electric control light beam deflection device and preparation method thereof

Abstract

The invention provides a planar large-angle electric control light beam deflection device and a preparation method thereof.The planar large-angle electric control light beam deflection device comprises two control panels arranged in parallel and a liquid crystal layer clamped between the two control panels, and each control panel comprises a substrate, an electrode layer and a patterned light alignment layer which are sequentially stacked; the patterned light alignment layer is opposite to the liquid crystal layer; liquid crystal molecules in the liquid crystal layer form a periodic arrangement structure under the action of the patterned light alignment layer and the molecular force of the liquid crystal molecules, and the periodic arrangement structure is an adjustable phase wedge surface structure and is used for deflecting an incident light beam. The phase wedge surface is formed in the liquid crystal layer through the patterning of the optical alignment layer and the molecular force of the liquid crystal molecules; and the inclination angle of the phase wedge surface is adjusted through the electrode layer, so that the deflection angle of the incident light beam is continuously changed, and the light beam scanning function is realized. The device has the advantages of small size, low thickness, large light beam deflection angle and high deflection efficiency.

Description

Technical Field

[0001] This invention relates to the field of beam deflection technology, and in particular to a planar large-angle electrically controlled beam deflection device and its fabrication method. Background Technology

[0002] Beam deflection technology is a technique for dynamically and precisely controlling the direction of a emitted light beam, offering advantages such as accuracy, agility, compactness, and strong confidentiality. This technology has broad application prospects in numerous fields, including vehicle radar, optical information processing and storage, biomedicine, and military countermeasures.

[0003] Traditional beam deflection techniques include, for example Figure 1 The wedge prism shown uses a glass substrate as its base, on which multiple wedge prisms of identical shape and size are placed. According to the law of refraction, a light beam passing perpendicularly from the glass substrate through the prism along the direction of the arrow will be deflected, with the deflection angle related to the prism's tilt angle; simultaneously, the optical path difference of the beam will change, correspondingly altering the phase. To achieve a wide range of beam deflection, the tilt angle of the wedge prism needs to be increased, which simultaneously increases the prism's thickness and volume, hindering device miniaturization. Furthermore, while current liquid crystal phased arrays can achieve electrically controllable beams and high deflection accuracy, they suffer from high losses and small deflection angles. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a planar large-angle electrically controlled beam deflection device, which forms a phase wedge surface within the liquid crystal layer through a patterned photoalignment layer and the molecular forces of the liquid crystal molecules themselves; then, by adjusting the tilt angle of the phase wedge surface through an electrode layer, the deflection angle of the incident beam is continuously changed, thereby realizing the function of beam scanning. It has the advantages of small size, low thickness, large beam deflection angle, and high deflection efficiency.

[0005] The present invention provides a planar large-angle electrically controlled beam deflection device, comprising two parallel control boards and a liquid crystal layer sandwiched therebetween. The control board comprises a substrate, an electrode layer and a patterned photoalignment layer stacked in sequence, with the patterned photoalignment layer facing the liquid crystal layer.

[0006] The liquid crystal molecules in the liquid crystal layer form a periodic arrangement structure under the action of the patterned photoalignment layer and their own molecular forces. The periodic arrangement structure is an adjustable phase wedge structure, which is used to deflect the incident light beam.

[0007] Specifically, the liquid crystal molecules exhibit a continuous linear periodic change along the transverse axis of the liquid crystal layer, with the azimuth angle of their direction vector as the variable, wherein the azimuth angle has a period of 0° to 180°.

[0008] Specifically, the liquid crystal molecules are cholesteric liquid crystal molecules, and the liquid crystal molecules self-assemble along the longitudinal axis of the liquid crystal layer to form a periodic change, with a period of 0° to 180°.

[0009] Specifically, the liquid crystal molecules form a phase wedge with a periodic change, and the liquid crystal layer includes a plurality of phase wedges.

[0010] Specifically, the ratio of the horizontal to the vertical period of the liquid crystal layer and the refractive index of the liquid crystal molecules determine the refraction angle of the incident light beam, and the refraction angle satisfies the law of refraction.

[0011] Specifically, the electrode layer is a metal conductive thin film, and the electrode layer is used to adjust the tilt angle of the phase wedge surface and change the deflection angle of the emitted beam.

[0012] Specifically, the deflection angle is 10° to 15°.

[0013] Specifically, when the electrode layer applies a voltage to the liquid crystal molecules, the liquid crystal molecules tilt in the horizontal and vertical directions of the liquid crystal layer, and when the voltage is at its maximum, the liquid crystal molecules are perpendicular to the control plate on the vertical axis of the liquid crystal layer.

[0014] Specifically, the control board comprises a top control board and a bottom control board. The bottom control board further includes a reflective layer, which is disposed on the side of the patterned photoalignment plane of the bottom control board facing the liquid crystal layer, for reflecting the incident light beam from the liquid crystal layer back to the liquid crystal layer.

[0015] This invention also provides a method for fabricating a planar large-angle electrically controlled beam deflection device, the method comprising:

[0016] Provide substrate;

[0017] Using the surface of the substrate as the bearing surface, an electrode layer is formed on the bearing surface;

[0018] A patterned photoalignment layer is then fabricated on the surface of the electrode layer away from the substrate to form a control board;

[0019] Two control boards are arranged in parallel as a top control board and a bottom control board, with the patterned photoalignment layers facing each other. Four substrates are then used as side plates and assembled with the two control boards to form a housing. Liquid crystal molecules are injected into the housing to form a liquid crystal layer. Under the induction of their own molecular forces and the patterned photoalignment layer, the liquid crystal molecules form a periodic arrangement structure, which is an adjustable phase wedge structure.

[0020] In summary, the planar large-angle electrically controlled beam deflection device of the present invention can form a phase wedge surface within the liquid crystal layer through a patterned photoalignment layer and the molecular forces of the liquid crystal molecules themselves; then, by adjusting the tilt angle of the phase wedge surface through the electrode layer, the deflection angle of the incident beam can be continuously changed, thereby realizing the beam scanning function. It has the advantages of small size, low thickness, large beam deflection angle, and high deflection efficiency.

[0021] Furthermore, in the initial state, under the influence of the patterned photoalignment film and their own molecular forces, the liquid crystal molecules form a wedge-shaped angle with the control plate, causing the light beam to refract as it passes through the liquid crystal molecules. When the liquid crystal molecules' pointing vector is perpendicular to the control plate, the angle is 90 degrees, and the light beam passes through the liquid crystal molecules without refraction, resulting in a zero deflection angle for the emitted beam. As the pointing vector of the liquid crystal molecules changes from the initial state to perpendicular to the control plate, the deflection angle of the emitted beam gradually decreases from its maximum to zero. Conversely, as the pointing vector of the liquid crystal molecules changes from perpendicular to the control plate back to the initial state, the deflection angle of the emitted beam gradually increases from zero to its maximum, achieving the beam scanning effect.

[0022] Furthermore, the liquid crystal molecules form a phase wedge with a periodic change, and the liquid crystal layer includes multiple phase wedges. A periodic change in the liquid crystal molecules corresponds to the formation of a traditional wedge prism, and the phase wedge corresponds to the inclined surface of a traditional wedge prism. By applying voltage to the electrode layer, the tilt angle of the phase wedge is changed, thereby altering the deflection angle of the emitted beam. This achieves an effect similar to changing the inclined surface angle of a traditional wedge prism.

[0023] Furthermore, one of the bottom control boards also includes a reflective layer, which is used to reflect the incident light beam from the liquid crystal layer back to the liquid crystal layer. The reflective layer is disposed on the side of the patterned photoalignment plane of the bottom control board facing the liquid crystal layer to form a reflective planar large-angle electrically controlled beam deflector, in which the incident beam and the outgoing beam are located on the same side, thereby improving the applicability of the planar large-angle electrically controlled beam deflector. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a wedge prism in the prior art;

[0026] Figure 2 This is a side cross-sectional view of the planar large-angle electrically controlled beam deflection device in the first embodiment of the present invention;

[0027] Figure 3 for Figure 2 A magnified view of a portion of region A in the middle;

[0028] Figure 4 This is a top view of the first sub-liquid crystal layer in the first embodiment of the present invention;

[0029] Figure 5 This is a top view of the second sub-liquid crystal layer in the first embodiment of the present invention;

[0030] Figure 6 This is a top view of the third sub-liquid crystal layer in the first embodiment of the present invention;

[0031] Figure 7 This is a side cross-sectional view of the planar large-angle electrically controlled beam deflection device when the voltage of the electrode layer is at its maximum in the first embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure of wedge prisms with different tilt angles in the prior art;

[0033] Figure 9 This is a side cross-sectional view of the planar large-angle electrically controlled beam deflection device in the second embodiment of the present invention;

[0034] Figure 10 for Figure 9 A magnified view of a portion of region B in the middle.

[0035] In the above figures, the reference numerals for the embodiments of the present invention are as follows:

[0036] 100. Control board; 110. Substrate; 120. Electrode layer; 130. Patterned photoalignment layer;

[0037] 200. Liquid crystal layer; 210. Sub-liquid crystal layer; 211. Liquid crystal alignment; 212. Liquid crystal molecules; 220. Phase wedge surface;

[0038] 300. Reflective layer. Detailed Implementation

[0039] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0040] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0041] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0042] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar attributes, not to indicate or imply relative importance or a specific order.

[0043] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0044] The following detailed description uses specific examples.

[0045] like Figures 2 to 3 As shown, the first embodiment of the present invention provides a planar large-angle electrically controlled beam deflection device, including two parallel control plates 100 and a liquid crystal layer 200 sandwiched between them. The control plate 100 includes a substrate 110, an electrode layer 120, and a patterned photoalignment layer 130 stacked sequentially, with the patterned photoalignment layer 130 facing the liquid crystal layer 200. Liquid crystal molecules 212 within the liquid crystal layer 200 form a periodic arrangement structure under the action of the patterned photoalignment layer 130 and their own molecular forces. This periodic arrangement structure is an adjustable phase wedge surface 220 structure, used to deflect the incident beam.

[0046] In this embodiment, the electrode layer 120 is a metal conductive film, optionally an ITO film or a silver nanowire conductive film. The electrode layer 120 is used to adjust the tilt angle of the phase wedge surface 220, thereby changing the deflection angle of the emitted beam. In this embodiment, the deflection angle is 10° to 15°.

[0047] like Figures 2 to 7As shown, the X-axis is parallel to the control board 100, and the direction indicated by the X-axis is the horizontal axis of the liquid crystal layer 200; the Z-axis is perpendicular to the control board 100, and the direction indicated by the Z-axis is the vertical axis of the liquid crystal layer 200; the Y-axis is perpendicular to the XOZ plane. The directions of the X-axis, Y-axis, and Z-axis correspond to the length, width, and height directions of the planar large-angle electrically controlled beam deflector, respectively.

[0048] like Figures 2 to 6 As shown, in this embodiment, the liquid crystal molecules 212 exhibit a continuous linear periodic change along the horizontal axis of the liquid crystal layer 200, with the azimuth angle of their pointing vector as the variable. The azimuth angle has a period of 0° to 180°. Specifically, there are many liquid crystal molecules 212 in the liquid crystal layer 200, which can be understood as countless on a microscopic scale. For ease of understanding, the accompanying drawings magnify and simplify the number and structure of the liquid crystal molecules 212 within the liquid crystal layer 200.

[0049] Specifically, such as Figures 4 to 6 As shown, in this embodiment, the liquid crystal layer 200 can be simplified into multiple sub-liquid crystal layers 210, which are stacked together in sequence. Figure 4 The multilayer liquid crystal layers 210 are arranged sequentially from top to bottom. Liquid crystal molecules 212 are induced by the patterned photoalignment layer 130 to form multiple... Figure 4 The liquid crystal arrangement 211 is unidirectionally arranged along the horizontal axis. The liquid crystal molecules 212 within it rotate their azimuth angles in 45° increments. The start and end points of each liquid crystal arrangement 211 are aligned along the Y-axis. The unit of rotation is not limited to 45° and can be other degrees. Specifically, Figure 4 For ease of understanding, it is simplified to 4 liquid crystal arrangements 211. In fact, the same sub-liquid crystal layer 210 contains an almost infinite number of liquid crystal arrangements 211.

[0050] Specifically, such as Figure 4 As shown in the figure, a table below is attached showing the θ values ​​for the corresponding positions of liquid crystal molecules 212, where θ is the azimuth angle of the liquid crystal molecule 212. The patterned photoalignment layer 130 induces the azimuth angle of the liquid crystal molecule 212 to change linearly from left to right along the X-axis, with each change being a quarter of a π (45°), causing a continuous phase change. The azimuth angle of the liquid crystal molecule 212 from 0 to π corresponds to one cycle of phase change, π to 2π corresponds to the second cycle of phase change, and so on, with each cycle corresponding to a wedge prism. In this way, the beam deflection device is completely equivalent to a traditional wedge prism.

[0051] In this embodiment, the liquid crystal molecules 212 are cholesteric liquid crystal molecules. The liquid crystal molecules 212 self-assemble along the longitudinal axis of the liquid crystal layer 200 to form a periodic variation, with a period of 0° to 180°. The liquid crystal molecules 212 within the liquid crystal layer 200 self-assemble along the longitudinal axis of the liquid crystal layer 200 to form a periodic structure. In this embodiment, the liquid crystal molecules 212 form a phase wedge 220 with a periodic variation, and the liquid crystal layer 200 includes multiple phase wedges 220. Specifically, for ease of understanding, the liquid crystal molecules 212 within the liquid crystal layer 200 are approximately arranged in a three-dimensional matrix. This three-dimensional matrix has a length equal to the period of the liquid crystal arrangement 211 (i.e., the horizontal period of the liquid crystal layer 200), a height equal to the period of the liquid crystal molecules 212 along the longitudinal axis of the liquid crystal layer 200 (i.e., the vertical period of the liquid crystal layer 200), and a width equal to the width of the liquid crystal layer 200 (i.e., the length of the liquid crystal layer 200 along the Y-axis), and is divided into multiple sub-matrices. The liquid crystal molecules 212 on the diagonal surfaces formed by the continuous horizontal and vertical periodic diagonals of each submatrix have the same azimuth angle, forming a phase wedge surface 220.

[0052] This invention relies on the principle of liquid crystal geometric phase and the principle of light-controlled liquid crystal orientation, combined with the interaction force of the molecules of cholesteric phase (chiral nematic phase) liquid crystal, to form an adjustable phase wedge surface 220 to deflect the light beam. This solves the problems of large volume and thickness of traditional wedge prisms and small deflection angle of liquid crystal phased arrays. It has the advantages of small volume, low thickness, large beam deflection angle and high deflection efficiency.

[0053] Specifically, liquid crystal molecules 212 readily rearrange themselves under the influence of external conditions such as electric and magnetic fields, and their electro-optic properties, based on the anisotropy of liquid crystal optical properties, also change accordingly. By using photo-controlled liquid crystal alignment, polarized ultraviolet light is irradiated into a patterned photoalignment layer 130 to induce a photochemical reaction, generating anisotropy and thereby inducing the alignment of liquid crystal molecules 212. Since the magnitude of the geometric phase of liquid crystal is usually proportional to the azimuth angle of the director of the effective local liquid crystal molecules 212 and has polarization-dependent characteristics, phase modulation is achieved by changing the direction of the director (optical axis) of the liquid crystal molecules 212 in the liquid crystal layer using the principle of liquid crystal geometric phase. The photo-controlled liquid crystal alignment technology induces different degrees of deflection of liquid crystal molecules 212 in the XOY plane, achieving phase modulation. Combined with the periodic structure formed by the self-assembly of cholesteric liquid crystal in the Z-axis direction, an adjustable phase wedge surface 220 is formed. This adjustable phase wedge surface 220 deflects the incident light, realizing the function of a traditional wedge prism. By applying a driving voltage, the tilt angle of the phase wedge 220 is changed according to the voltage change, thereby realizing the function of beam scanning.

[0054] In this embodiment, when the electrode layer 120 applies a voltage to the liquid crystal molecules 212, the liquid crystal molecules 212 tilt in the horizontal and vertical directions of the liquid crystal layer 200, and when the voltage is at its maximum, the liquid crystal molecules 212 are perpendicular to the control plate 100 on the vertical axis of the liquid crystal layer 200. Specifically, when the electrode layer 120 does not apply a voltage to the liquid crystal molecules 212, the liquid crystal molecules 212 in the initial state form an acute angle with the control plate 100 under the action of the patterned photoalignment layer 130 and their own molecular forces, and the liquid crystal molecules 212 are tilted on the vertical axis and are not completely parallel to the substrate; when the electrode layer 120 applies a voltage to the liquid crystal molecules 212, the pointing vector of the liquid crystal molecules 212 gradually points towards the control plate 100, the angle gradually increases, and when the voltage is at its maximum, the pointing vector of the liquid crystal molecules 212 is perpendicular to the control plate 100.

[0055] The beam deflection device in this embodiment is similar to a wedge prism, exhibiting high deflection efficiency. To obtain a beam deflection device with a large angle, the minimum resolution size must also be considered. For example... Figure 8 As shown, with the increase of the tilt angle, the base length of a traditional wedge prism must continuously decrease to maintain a 2π phase period (i.e., a constant thickness). The phase-shifting unit array length in traditional techniques is between 1 μm and 5 μm, resulting in a limited beam deflection angle. However, the beam deflection device in this embodiment utilizes photo-controlled liquid crystal alignment technology, which can reduce the unit length to approximately 0.5 μm, achieving a higher resolution and a larger deflection angle compared to traditional techniques.

[0056] In this embodiment, the ratio of the horizontal to vertical period of the liquid crystal layer 200 and the refractive index of the liquid crystal molecules 212 determine the refraction angle of the incident light beam, and the refraction angle satisfies the law of refraction. Specifically, as shown... Figure 2 As shown, when the two electrode layers 120 are connected to a power source and the power source is turned off, a beam of linearly polarized light is incident perpendicularly into the beam deflection device along the z-axis. The beam will be deflected after passing through the phase wedge surface 220 formed by the liquid crystal molecules 212.

[0057] like Figure 3As shown, the beam deflection device in this embodiment is a transmission type, meaning the beam enters from one side and exits from the other. The dashed lines in the figure are auxiliary lines. The deflection angle can be calculated using the ratio of the longitudinal and transverse periods of the liquid crystal molecules 212 to the refractive index of the chiral liquid crystal: First, let the ratio of the longitudinal period to the transverse period be x, then the angle between the adjustable phase wedge 220 and the substrate 110 is arctanx, and the incident angle of the beam hitting the phase wedge 220 is θm; then, according to the law of refraction n1sinθm=n2sinθi, the refraction angle θi of the incident beam after passing through the phase wedge 220 is calculated, where n1 is the refractive index of the cholesteric liquid crystal (1.5~1.7), and n2 is equivalent to the air layer with a refractive index of 1; finally, the incident beam passes through the glass plate and exits the beam deflection device, becoming the outgoing beam, with an outgoing angle θ1=θi-θm, where θ1 is the final deflection angle, and the deflection of the beam passing through the control plate can be ignored. The deflection angle of the beam deflection device in this embodiment is between 10° and 15°, while the deflection angle of traditional technology is generally only 1 to 2°. This embodiment can significantly increase the deflection angle of the emitted beam.

[0058] In this embodiment, as Figure 7 As shown, after the power is turned on and a saturation voltage is applied, the liquid crystal molecules 212 are straightened. At this time, the incident light will pass directly through the liquid crystal layer 200 without modulation and no beam deflection will occur. As the voltage applied by the control power supply changes, the liquid crystal molecules 212 deflect to different degrees, and the tilt angle of the phase wedge surface 220 is deflected, so that the angle of the emitted beam changes continuously, achieving the effect of beam scanning.

[0059] like Figures 9 to 10 As shown, the arrows indicate the path of the light beam. The second embodiment of the present invention provides a planar large-angle electrically controlled beam deflection device. Compared with the first embodiment, one of the control boards 100 further includes a reflective layer 300, which is used to reflect the incident light beam from the liquid crystal layer 200 back to the liquid crystal layer 200.

[0060] In this embodiment, the control board 100 comprises a top control board and a bottom control board. The bottom control board further includes a reflective layer 300, which is disposed on the side of the patterned photoalignment layer 130 of the bottom control board facing the liquid crystal layer 200, and is used to reflect the incident light beam from the liquid crystal layer 200 back to the liquid crystal layer 200. The top control board refers to the control board 100 located above the liquid crystal layer 200, and the bottom control board refers to the control board 100 located below the liquid crystal layer 200.

[0061] The beam deflection device in this embodiment is a reflective type, with the beam entering and exiting on the same side. Specifically, the reflective layer 300 is a mirror, and the reflective surface of the reflective layer 300 faces the liquid crystal layer 200. Similar to the calculation method for the transmissive type, given the ratio of the horizontal and vertical periods and the incident angle θm, the deflection angle θ4 of the reflective type is calculated to be between 12° and 15° using the law of refraction, which is a significant improvement compared to the 1-2° deflection angle of traditional technology. At the same time, this expands the applicability of the planar large-angle electrically controlled beam deflection device.

[0062] This invention also provides a method for fabricating a planar large-angle electrically controlled beam deflection device, the method comprising:

[0063] Step S1: Provide substrate 110;

[0064] Step S2: Using the surface of the substrate 110 as the bearing surface, an electrode layer 120 is fabricated on the bearing surface;

[0065] Step S3: A patterned photoalignment layer 130 is fabricated on the surface of the electrode layer 120 away from the substrate 110 to form the control plate 100.

[0066] Step S4: Take two control boards 100 and set them in parallel as the top control board and the bottom control board, and set the patterned photoalignment layer 130 facing each other; then take four substrates 110 as side plates and assemble them with the two control boards 100 to form a box; inject liquid crystal molecules 212 into the box to form a liquid crystal layer 200. Under the induction of their own molecular forces and the patterned photoalignment layer 130, the liquid crystal molecules 212 form a periodic arrangement structure, which is an adjustable phase wedge surface 220 structure.

[0067] In step S1 above, optionally, for example, the planar large-angle electrically controlled beam deflection device has a length of 35mm, a width of 25mm, and a height of 5mm, and the substrate 110 is a glass substrate with a thickness of 2mm.

[0068] In step S2 above, an electrode layer is deposited on the substrate 110. Optionally, for example, the electrode layer is an ITO thin film or a silver nanowire conductive thin film. The deposition thickness is 10 μm. The two electrode layers 120 apply voltage to the liquid crystal layer 200 from both top and bottom directions, and current flows within the liquid crystal layer 200.

[0069] In step S3 above, the patterned photoalignment layer 130 is a photoalignment film. The specific fabrication method of the patterned photoalignment layer 130 is as follows: a layer of SD1 material with a thickness of 200nm to 300nm is spin-coated on the electrode layer 120 at a rotation speed of 2000r / min and a rotation time of 120s; the temperature is controlled at about 50℃, and SD1 is irradiated with 450nm linearly polarized light for 5 minutes to form the patterned photoalignment layer 130.

[0070] In step S4 above, the side plate includes four substrates 110, which are assembled together with the top control board and the bottom control board into a glass box. The specific method for injecting liquid crystal molecules 212 into the box to form liquid crystal layer 200 is as follows: a small hole is made on the side of a glass box, and liquid crystal is injected into it. Under the induction of the patterned photoalignment film, the liquid crystal molecules 212 of the bottom and top layers will be deflected to different degrees in the XOY plane. The liquid crystal molecules 212 in the longitudinal direction (Z-axis direction) self-assemble to form a periodic structure through molecular forces.

[0071] In summary, the planar large-angle electrically controlled beam deflection device of this invention requires only a single alignment of a single-layer liquid crystal functional layer, resulting in a simpler structure. Furthermore, the ratio of the liquid crystal refractive index to the transverse and longitudinal periods can be adjusted over a wide range, significantly increasing the polarization angle. This not only miniaturizes traditional wedge prisms but also overcomes the limitations of small deflection angles in small devices such as liquid crystal phased arrays, offering significant advantages in mass production and versatility.

[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A planar large-angle electrically controlled beam deflection device, characterized in that, It includes two parallel control boards (100) and a liquid crystal layer (200) sandwiched between them. The control board (100) includes a substrate (110), an electrode layer (120) and a patterned photoalignment layer (130) stacked in sequence. The patterned photoalignment layer (130) is disposed opposite to the liquid crystal layer (200). The liquid crystal molecules (212) in the liquid crystal layer (200) form a periodic arrangement structure under the action of the patterned photoalignment layer (130) and their own molecular forces. The periodic arrangement structure is an adjustable phase wedge (220) structure, which is used to deflect the incident light beam.

2. The planar large-angle electrically controlled beam deflection device as described in claim 1, characterized in that, The liquid crystal molecules (212) exhibit a continuous linear periodic change along the transverse axis of the liquid crystal layer (200) with the azimuth angle of their pointing vector as the variable, wherein the azimuth angle has a period of 0° to 180°.

3. The planar large-angle electrically controlled beam deflection device as described in claim 1, characterized in that, The liquid crystal molecule (212) is a cholesteric liquid crystal molecule. The liquid crystal molecule (212) self-assembles along the longitudinal axis of the liquid crystal layer (200) to form a periodic change with a period of 0° to 180°.

4. The planar large-angle electrically controlled beam deflection device as described in claim 1, characterized in that, The liquid crystal molecules (212) form a phase wedge (220) with a periodic change, and the liquid crystal layer (200) includes a plurality of the phase wedges (220).

5. The planar large-angle electrically controlled beam deflection device as described in claim 1, characterized in that, The ratio of the horizontal to the vertical period of the liquid crystal layer (200) and the refractive index of the liquid crystal molecules (212) determine the refraction angle of the incident light beam, and the refraction angle satisfies the law of refraction.

6. The planar large-angle electrically controlled beam deflection device as described in claim 1, characterized in that, The electrode layer (120) is a metal conductive thin film. The electrode layer (120) is used to adjust the tilt angle of the phase wedge surface (220) and change the deflection angle of the emitted beam.

7. The planar large-angle electrically controlled beam deflection device as described in claim 6, characterized in that, The deflection angle is 10° to 15°.

8. The planar large-angle electrically controlled beam deflection device as described in claim 6, characterized in that, When the electrode layer (120) applies a voltage to the liquid crystal molecule (212), the liquid crystal molecule (212) tilts in the horizontal and vertical directions of the liquid crystal layer (200), and when the voltage is at its maximum, the liquid crystal molecule (212) is perpendicular to the control board (100) on the vertical axis of the liquid crystal layer (200).

9. The planar large-angle electrically controlled beam deflection device as described in claim 1, characterized in that, The control board (100) consists of a top control board and a bottom control board. The bottom control board further includes a reflective layer (300). The reflective layer (300) is disposed on the side of the patterned photoalignment layer (130) of the bottom control board facing the liquid crystal layer (200) and is used to reflect the incident light beam from the liquid crystal layer (200) back to the liquid crystal layer (200).

10. A method for fabricating a planar large-angle electrically controlled beam deflection device, characterized in that, The method includes: Provide a substrate (110); Using the surface of the substrate (110) as the bearing surface, an electrode layer (120) is formed on the bearing surface; A patterned photoalignment layer (130) is then fabricated on the surface of the electrode layer (120) away from the substrate (110) to form a control plate (100); Two control boards (100) are arranged in parallel as a top control board and a bottom control board, and the patterned photoalignment layer (130) is arranged facing each other; four substrates (110) are then arranged as side plates and assembled with the two control boards (100) to form a box; liquid crystal molecules (212) are injected into the box to form a liquid crystal layer (200), and the liquid crystal molecules (212) form a periodic arrangement structure under the induction of their own molecular force and the patterned photoalignment layer (130), and the periodic arrangement structure is an adjustable phase wedge (220) structure.

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