Design method of liquid crystal waveguide beam scanner based on fringe field effect

Abstract

The invention relates to the technical field of optical waveguides, in particular to a design method of a liquid crystal waveguide beam scanner based on a fringe field effect. Comprising an electrode layer, a liquid crystal orientation layer, a liquid crystal cladding layer, a liquid crystal orientation layer, a waveguide core layer, a substrate layer and a coupling base which are stacked in sequence; based on an influence rule of a liquid crystal fringe field on energy loss, establishing a relation model among the liquid crystal cladding thickness, the energy transmittance and the working voltage; s2, based on the refractive index law, according to the relation model in the step S2, balancing the energy transmittance and the required working voltage, and selecting the liquid crystal cladding thickness; designing an electrode layer structure for realizing the maximum scanning angle according to the thickness of the liquid crystal cladding; and the structure of the electrode layer is optimized, so that the energy transmittance is further improved. The system has the advantages that light beam deflection with high energy transmittance can be realized through design, and various application requirements, including vehicle-mounted radar detection distance improvement, laser display image brightness improvement and the like, can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of optical waveguides, and in particular to a design method of a liquid crystal waveguide light beam scanner based on fringe field effect. Background Art

[0002] The liquid crystal waveguide beam scanner is a novel beam scanning device that uses a waveguide as a carrier and liquid crystal as a working medium. The waveguide, as its core structure, provides a stable and efficient channel for the transmission of optical signals. Liquid crystal, with its unique physical properties, plays a crucial role in the beam scanning process. By precisely controlling the alignment of the liquid crystal molecules, the refractive properties of light within the waveguide can be dynamically controlled. This, in turn, synergistically coupled with the prism coupling process outside the waveguide, enables precise beam scanning control. This design not only leverages the low-loss transmission advantages of the waveguide but also leverages the controllability of liquid crystal to achieve flexible and efficient beam scanning.

[0003] Liquid crystal waveguide beam scanners utilize the refraction of light within a waveguide coupled with a prism outside the waveguide to achieve beam scanning control. They feature on-chip integration, are fully solid-state, high-speed, and capable of two-dimensional continuous scanning. Compared to existing scanning technologies such as traditional mechanical, MEMS, silicon-based optical phased arrays, and liquid crystal optical phased arrays, they offer advantages such as high stability, low power consumption, concentrated beam energy, and a wide scanning angle. They hold significant application value in radar detection, laser communications, and laser displays. Specifically, while traditional mechanical scanning devices are technologically mature, they suffer from complex mechanical structures, poor stability, and are susceptible to interference from external environmental factors. Furthermore, their scanning speed is limited by the inertia of their mechanical components, making them difficult to achieve high-speed scanning. In contrast, the fully solid-state structure and high-speed scanning capabilities of liquid crystal waveguide beam scanners offer advantages in stability and speed. While microelectromechanical system (MEMS) scanning devices have overcome the size and speed limitations of traditional mechanical scanning devices to some extent, they still rely on tiny moving mechanical components, subject to wear and reliability issues over long-term operation. Furthermore, their scanning angle and accuracy are limited by manufacturing processes, making it difficult to achieve wide-range, high-precision scanning. Liquid crystal waveguide beam scanners achieve scanning through optical control and are not restricted by mechanical movement. They have a large scanning angle and high precision, and can meet the needs of a wider range of application scenarios. Although silicon-based optical phased array scanning devices have advantages such as high integration and fast scanning speed, their beam energy distribution is relatively dispersed, making it difficult to achieve beam output with high energy concentration. This is a clear shortcoming in some applications that require high beam energy density. Liquid crystal waveguide beam scanners, on the other hand, can achieve efficient and concentrated output of beam energy by optimizing the optical design of the waveguide and liquid crystal, ensuring the energy utilization efficiency of the beam during transmission, thereby exerting greater advantages in fields such as laser communications and laser processing. Although liquid crystal optical phased array scanning devices have certain similarities with liquid crystal waveguide beam scanners in terms of operating principles, they usually require complex electrode structures and drive circuits to achieve beam scanning, which leads to high power consumption and limits their use in some power-sensitive application scenarios.

[0004] Despite the numerous advantages of liquid crystal waveguide beam scanners, traditional liquid crystal waveguide beam scanners still face some technical challenges that need to be addressed in practical applications. The most prominent of these is the low and unstable energy transmittance. The energy transmittance of beam scanning is one of the key indicators for measuring scanner performance. It is directly related to the degree of energy loss of the beam during the scanning process, as well as the intensity and quality of the final output beam. In practical applications, the energy transmittance of beam scanning is affected by a combination of factors, such as the optical loss of the waveguide, the optical properties of the liquid crystal, and the coupling efficiency between the waveguide and the prism. Low energy transmittance not only leads to energy loss during the scanning process, reducing the brightness and power of the beam, but may also affect the quality and stability of the beam, thereby limiting the development of liquid crystal waveguide beam scanners in some applications that require higher beam energy. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a design method of a liquid crystal waveguide beam scanner based on fringe field effect.

[0006] The present invention aims to provide a method for designing a liquid crystal waveguide beam scanner based on the fringe field effect, which specifically includes the following steps: S1. Determine the basic structure of the liquid crystal waveguide beam scanner, including the stacked electrode layer, liquid crystal alignment layer, liquid crystal cladding layer, liquid crystal alignment layer, waveguide core layer, substrate layer, and coupling substrate; S2. Based on the influence of liquid crystal fringe fields on energy loss, a model is established to determine the relationship between liquid crystal cladding thickness, energy transmittance, and operating voltage. S3 based on the refractive index law, according to the relationship model of step S2, weigh the energy transmittance and the required operating voltage, select the liquid crystal cladding thickness; S4. Design an electrode layer structure that achieves the maximum scanning angle based on the thickness of the liquid crystal cladding layer; S5. Optimize the electrode layer structure to further improve energy transmittance.

[0007] Preferably, the method for establishing the relationship model between the liquid crystal cladding thickness, energy transmittance and operating voltage in step S2 is as follows: S21. Using the theory of continuous elastic bodies, calculate the distribution of directors of liquid crystal molecules in the liquid crystal cladding under an applied electric field. S22. Determine the dielectric tensor distribution of the liquid crystal waveguide beam scanner based on the distribution of directors of the liquid crystal molecules in the liquid crystal cladding layer and the optical dielectric constants and thicknesses of each layer. S23. Substitute the dielectric tensor distribution in step S22 into Maxwell's equations to solve the effective refractive index and energy transmittance of the waveguide mode.

[0008] Preferably, the equation of the director in step S21 is as follows: ; in: F tot is the total free energy; It represents the elastic free energy density, which describes the free energy generated by the liquid crystal molecules due to deformation; It represents the electric free energy density, which describes the free energy generated by the polarization of liquid crystal molecules in the electric field; represents the gradient operator; is the bending elastic constant of the liquid crystal molecules; is the twist elastic constant of the liquid crystal molecules; is the splay elastic constant of the liquid crystal molecules; is the liquid crystal director distribution; is the electric field strength; is the electric displacement vector.

[0009] Preferably, the dielectric tensor expression in step S22 is as follows: ; in: represents the dielectric tensor; is the ordinary refractive index of the liquid crystal molecules; is the extraordinary refractive index of the liquid crystal molecules; θ Indicates the orientation angle of liquid crystal molecules.

[0010] Preferably, step S3 specifically includes the following sub-steps: S31. Calculate the deflection angle caused by the change in the effective refractive index of the waveguide mode under different voltages; S32. Calculate the energy transmittance of the single refractive interface under different voltage conditions for different liquid crystal cladding thicknesses; S33. Calculate the effective refractive index change of the waveguide mode for different liquid crystal cladding thicknesses and different voltages; S34. Calculate the drive voltage required to achieve the same effective refractive index change in the waveguide mode at different liquid crystal cladding thicknesses; S35. Weigh the energy transmittance and driving voltage, and select the thickness of the liquid crystal cladding according to the voltage range limited by the application requirements.

[0011] Preferably, the specific optimization method in step S5 is: Make slight adjustments to the electrode layer structure that achieves the maximum scanning angle, and evaluate the relative increase in energy transmittance and the relative decrease in scanning angle after adjustment; if the relative increase in energy transmittance is greater than the relative decrease in scanning angle, accept the change in electrode layer structure; otherwise, continue to make adjustments; and repeat the iterative process until the optimal state is reached.

[0012] Preferably, in step S5, the relative increase in energy transmittance=the increase in energy transmittance / the original energy transmittance; and the relative decrease in scanning angle=the decrease in scanning angle / the original scanning angle.

[0013] Compared with the prior art, the present invention can achieve the following beneficial effects: The present invention discloses a design method for a liquid crystal waveguide beam scanner based on the fringe field effect. This method is based on the influence of the liquid crystal fringe field on the energy loss of the liquid crystal waveguide beam scanner. By designing the liquid crystal cladding thickness and electrode structure, this design can achieve high-energy transmittance beam deflection to meet various application requirements, including but not limited to improving the detection distance in vehicle-mounted radar applications and improving image brightness in laser display applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a flow chart of a design method for a liquid crystal waveguide beam scanner based on fringe field effect provided in accordance with an embodiment of the present invention.

[0015] Figure 2 2 is a schematic structural diagram of a liquid crystal waveguide beam scanner provided according to an embodiment of the present invention.

[0016] Figure 3 4 is a flow chart of the calculation process of the deflection angle, energy transmittance and effective refractive index provided according to an embodiment of the present invention.

[0017] Figure 4 Calculation results of single-refractive interface energy transmittance under different liquid crystal cladding thicknesses and voltages provided by an embodiment of the present invention.

[0018] Figure 5 1 is a calculation result of the required driving voltage under different liquid crystal layer thicknesses provided according to an embodiment of the present invention.

[0019] Figure 6 Schematic diagram of an optimized electrode layer structure provided according to an embodiment of the present invention.

[0020] Figure 7 2 is a diagram of energy efficiency test results provided according to an embodiment of the present invention.

[0021] Reference numerals: 1. Glass cover; 2. Electrode layer; 3. Liquid crystal alignment layer; 301. First liquid crystal alignment layer; 302. Second liquid crystal alignment layer; 4. Liquid crystal cladding; 5. Waveguide core layer; 6. substrate layer; 7. Coupling substrate; 8. Incident light; 9. Waveguide mode; 10. Emitting light. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0024] The present invention provides a design method for a liquid crystal waveguide beam scanner based on a fringe field effect, which specifically includes the following steps: S1. Determine the basic structure of the liquid crystal waveguide beam scanner; the liquid crystal waveguide beam scanner includes an electrode layer, a liquid crystal alignment layer, a liquid crystal cladding layer, a liquid crystal alignment layer, a waveguide core layer, a substrate layer, and a coupling substrate stacked in sequence; like Figure 2 As shown, the liquid crystal waveguide beam scanner includes functional layers stacked in sequence, such as an electrode layer 2, a liquid crystal alignment layer 3, a waveguide core layer 5, a substrate layer 6, and a coupling substrate 7. The liquid crystal alignment layer 3 includes a first liquid crystal alignment layer 301 and a second liquid crystal alignment layer 302, and the liquid crystal cladding layer 4 is disposed between the first alignment layer 301 and the second liquid crystal alignment layer 302. The coupling substrate 7 is a coupling prism for coupling a free-space beam (incident light) to the waveguide core layer 5. In a specific embodiment, the substrate layer 6 is disposed on the upper surface of the coupling substrate 7. The substrate layer 6 is made of silicon oxide material, has a refractive index of 1.46, and a thickness of 2 microns. The waveguide core layer 5 is disposed on the upper surface of the substrate layer 6. The waveguide core layer 5 is made of silicon oxynitride material, has a refractive index of 1.846, and is 590 nanometers thick. The waveguide core layer 5 is used to form a waveguide structure to guide the light beam to propagate therein. The material of the liquid crystal alignment layer 3 is azobenzenesulfonic acid material (SD1); the materials and functions of the first alignment layer 301 and the second liquid crystal alignment layer 302 are exactly the same, both of which are used to determine the initial arrangement direction of the liquid crystal molecules and affect the behavior of the liquid crystal molecules under the action of the electric field. The parameters of the liquid crystal molecules are: the long axis dielectric constant of the liquid crystal molecules =15.06, the short-axis dielectric constant of the liquid crystal molecule =3.70, the dielectric constant difference of liquid crystal molecules =11.36, pretilt angle is 2°; The liquid crystal cladding 4 is a positive liquid crystal material, whose refractive index can change under the stimulation of an electric field and change the effective refractive index of the waveguide mode in the waveguide; based on this adjustment mechanism, in conjunction with the coupling process between the upper electrode layer 2 (patterned electrode) and the coupling substrate 7, continuous scanning of a two-dimensional light beam can be achieved; the ordinary light refractive index of the liquid crystal cladding 4 is =1.4858, extraordinary refractive index =1.6226, thickness is 7 um; An electrode layer 2 is provided on the upper surface of the second liquid crystal alignment layer 302. The electrode layer 2 is a patterned electrode used to apply voltage. The patterned design can precisely control the arrangement of liquid crystal molecules, thereby controlling the scanning direction of the light beam. A glass cover plate 1 is also provided on the upper surface of the electrode layer 2 , which is usually made of a transparent material such as glass or plastic to protect the waveguide structure underneath.

[0025] In a specific embodiment, during operation, the liquid crystal waveguide beam scanner couples incident light 8 into the waveguide core layer 5 through the coupling substrate 7 and transmits the incident light 8 within the waveguide core layer 5. The wavelength corresponding to the transmitted waveguide mode 9 is 1550 nm.

[0026] When a light beam refracts between two regions with different effective refractive indices, energy loss occurs due to mode mismatch. However, the fringe field effect of the liquid crystal between the two regions causes the mode to change slowly, mitigating this energy loss. Increasing the thickness of the liquid crystal layer can extend the range of the fringe field effect, enhancing the mitigation effect and improving energy transmittance. This phenomenon of fringe field mitigation can serve as a theoretical basis for the design of high-energy-transmittance liquid crystal waveguide beam scanners.

[0027] S2. Based on the influence of the liquid crystal fringe field on energy loss, a model is established to determine the relationship between the liquid crystal cladding thickness, energy transmittance, and operating voltage. The establishment method is as follows: S21. Using the continuous elastic body theory, calculate the distribution of the director vectors of the liquid crystal molecules in the liquid crystal cladding 4 under an applied electric field; the equation for the director vector is as follows: ; in: F tot is the total free energy; It represents the elastic free energy density, which describes the free energy generated by the liquid crystal molecules due to deformation; It represents the electric free energy density, which describes the free energy generated by the polarization of liquid crystal molecules in the electric field; represents the gradient operator; is the bending elastic constant of the liquid crystal molecules, =10.6pN; is the twist elastic constant of the liquid crystal molecules, =9.0pN; is the splay elastic constant of the liquid crystal molecules, =15.5pN; is the liquid crystal director distribution; is the electric field strength; is the electric displacement vector.

[0028] S22. Based on the distribution of directors of the liquid crystal molecules in the liquid crystal cladding layer 4, combined with the optical dielectric constant and thickness of each layer, the dielectric tensor distribution of the liquid crystal waveguide beam scanner is obtained by substituting the following equation: ; in: represents the dielectric tensor; is the ordinary refractive index of the liquid crystal molecules, =1.4858; is the extraordinary refractive index of the liquid crystal molecules, =1.6226; θ Indicates the orientation angle of liquid crystal molecules.

[0029] S23. Substitute the dielectric tensor distribution of step S22 into Maxwell's equations to solve the effective refractive index and energy transmittance of waveguide mode 9; specifically, the scalar wave equation of Maxwell's equations is as follows: ; in: is the vacuum wave vector; Represents the square of the gradient operator, namely the Laplace operator, which is used to calculate the degree of change of a function in space; is the dielectric constant distribution of the medium; is the spatial distribution of the electric field; The effective refractive index is related to the eigenvalue equation of the waveguide mode: ; in: represents the square of the gradient operator; is the vacuum wave vector; is the electric field of the waveguide mode; α is the angle of the beam propagation direction relative to the y-axis; i represents the phase factor; is the waveguide propagation constant, which is related to the effective refractive index of the waveguide mode There is the following relationship between them: ; The energy transmittance can be determined by calculating the electric field of the waveguide mode and the light beam after passing through the interface 10, and the relationship is as follows: ; in: is the electric field of the light after passing through the interface, is the waveguide mode after passing through the interface, is the waveguide mode before passing through the interface.

[0030] S3. Based on the refractive index law and the relationship model of step S2, the optimal liquid crystal cladding thickness is selected by weighing the energy transmittance and the required operating voltage; specifically, the following steps are included: S31. Calculate the deflection angle caused by the change in the effective refractive index of the waveguide mode under different voltages ( Figure 3 This step is key to understanding how voltage affects the beam scan angle; the beam deflection direction is determined by the law of refraction: ; in: and are the effective refractive index and incident angle of the waveguide mode before passing through the interface, respectively, where and are the effective refractive index and the exit angle of the waveguide mode after passing through the interface; S32. Calculate the relationship between energy transmittance and voltage: For different liquid crystal cladding thicknesses, calculate the energy transmittance of the single refractive interface under different voltage conditions; The results are as follows Figure 4 , it is observed that the energy transmittance first increases and then decreases with increasing voltage, and increases significantly with increasing thickness of the liquid crystal cladding; S33. Calculate the effective refractive index change of the waveguide mode: For different liquid crystal cladding thicknesses and different voltages, calculate the effective refractive index change of the waveguide mode; The results are as follows Figure 5 , it is observed that the variation of the effective refractive index of the waveguide mode decreases with the increase of the thickness of the liquid crystal cladding; S34. Determine the relationship between the required driving voltage and the liquid crystal cladding thickness: Calculate the required driving voltage to achieve the same change in the effective refractive index of the waveguide mode (e.g., 90% of the maximum change) under different liquid crystal cladding thicknesses; obtain the required driving voltage corresponding to different liquid crystal cladding thicknesses.

[0031] S35. Weighing the energy transmittance and driving voltage, selecting the optimal liquid crystal cladding thickness according to the voltage range limited by the application requirements; For example, taking a voltage of 47V as an example, a liquid crystal cladding thickness of 7um needs to be selected.

[0032] Since increasing the thickness of the liquid crystal layer decreases the effective refractive index of the waveguide mode, reducing the scanning angle, it is necessary to increase the drive voltage to compensate for the reduced scanning angle. When selecting the thickness of the liquid crystal cladding, consider the trade-off between energy transmittance and the required drive voltage, and choose the liquid crystal cladding thickness that provides the highest energy transmittance within the specified voltage range.

[0033] S4. Designing an electrode layer structure that can achieve a maximum scanning angle based on the selected optimal liquid crystal cladding thickness; S5. Optimizing the electrode layer structure to further improve energy transmittance; Optimization includes but is not limited to adjusting the shape, size and spacing of the electrode layers; the specific optimization methods are: Based on the electrode layer structure that can achieve the maximum scanning angle, the electrode layer structure is slightly adjusted, and the relative increase in energy transmittance and the relative decrease in scanning angle after the adjustment are evaluated; If the relative increase in energy transmittance is greater than the relative decrease in scanning angle, the electrode layer structure change is accepted; otherwise, the adjustment is continued; Repeat the above-mentioned electrode layer structure change process until no more changes occur, that is, the optimal state; Relative increase in energy transmittance = increase in energy transmittance / original energy transmittance; The relative reduction of the scanning angle = the reduction of the scanning angle / the original scanning angle.

[0034] In a specific embodiment, the structure of the electrode layer 2 is as follows: Figure 6 shown.

[0035] Based on the above process, a high energy transmittance liquid crystal waveguide beam scanner can be designed. In a specific embodiment, the output light intensity test results of the device designed and prepared according to the above method are as follows: Figure 7 During the scanning process, the relative light intensity was above 95.2% (relative to 0 V), and the average energy transmittance of a single interface was greater than 99.7%.

[0036] By designing the thickness of the liquid crystal layer and the electrode structure according to the design method of the present invention, high-energy transmittance liquid crystal waveguide beam scanning can be achieved to meet various application requirements, including but not limited to improved detection distance in vehicle-mounted radar applications, improved image brightness in laser display applications, etc.

[0037] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. This is not limited herein.

[0038] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A design method for a liquid crystal waveguide beam scanner based on fringe field effect, characterized by: The specific steps include: S1. Determine the basic structure of the liquid crystal waveguide beam scanner, including the stacked electrode layer, liquid crystal alignment layer, liquid crystal cladding layer, liquid crystal alignment layer, waveguide core layer, substrate layer, and coupling substrate; S2. Based on the influence of liquid crystal fringe fields on energy loss, a model is established to determine the relationship between liquid crystal cladding thickness, energy transmittance, and operating voltage. S3 based on the refractive index law, according to the relationship model of step S2, weigh the energy transmittance and the required operating voltage, select the liquid crystal cladding thickness; S4. Design an electrode layer structure that achieves the maximum scanning angle based on the thickness of the liquid crystal cladding layer; S5. Optimize the electrode layer structure to further improve energy transmittance.

2. The method for designing a liquid crystal waveguide beam scanner based on fringe field effect according to claim 1, characterized in that: The method for establishing the relationship model between the liquid crystal cladding thickness, energy transmittance and operating voltage in step S2 is as follows: S21. Using the theory of continuous elastic bodies, calculate the distribution of directors of liquid crystal molecules in the liquid crystal cladding under an applied electric field. S22. Determine the dielectric tensor distribution of the liquid crystal waveguide beam scanner based on the distribution of directors of the liquid crystal molecules in the liquid crystal cladding layer and the optical dielectric constants and thicknesses of each layer. S23. Substitute the dielectric tensor distribution in step S22 into Maxwell's equations to solve the effective refractive index and energy transmittance of the waveguide mode.

3. The design method of a liquid crystal waveguide beam scanner based on fringe field effect according to claim 2, characterized in that: The equation of the director in step S21 is as follows: ； in: F tot is the total free energy; It represents the elastic free energy density, which describes the free energy generated by the liquid crystal molecules due to deformation; It represents the electric free energy density, which describes the free energy generated by the polarization of liquid crystal molecules in the electric field; represents the gradient operator; is the bending elastic constant of the liquid crystal molecules; is the twist elastic constant of the liquid crystal molecules; is the splay elastic constant of the liquid crystal molecules; is the liquid crystal director distribution; is the electric field strength; is the electric displacement vector.

4. The design method of a liquid crystal waveguide beam scanner based on fringe field effect according to claim 2, characterized in that: The dielectric tensor expression in step S22 is as follows: ； in: represents the dielectric tensor; is the ordinary refractive index of the liquid crystal molecules; is the extraordinary refractive index of the liquid crystal molecules; θ Indicates the orientation angle of liquid crystal molecules.

5. The method for designing a liquid crystal waveguide beam scanner based on fringe field effect according to claim 1, characterized in that: The step S3 specifically includes the following sub-steps: S31. Calculate the deflection angle caused by the change in the effective refractive index of the waveguide mode under different voltages; S32. Calculate the energy transmittance of the single refractive interface under different voltage conditions for different liquid crystal cladding thicknesses; S33. Calculate the effective refractive index change of the waveguide mode for different liquid crystal cladding thicknesses and different voltages; S34. Calculate the drive voltage required to achieve the same effective refractive index change in the waveguide mode at different liquid crystal cladding thicknesses; S35. Weigh the energy transmittance and driving voltage, and select the thickness of the liquid crystal cladding according to the voltage range limited by the application requirements.

6. The method for designing a liquid crystal waveguide beam scanner based on fringe field effect according to claim 1, characterized in that: The specific optimization method in step S5 is: Make minor adjustments to the electrode layer structure that achieves the maximum scanning angle, and evaluate the relative increase in energy transmittance and the relative decrease in scanning angle after the adjustment; if the relative increase in energy transmittance is greater than the relative decrease in scanning angle, accept the electrode layer structure change; otherwise, continue adjusting; Repeat the iterative process until the optimal state is reached.

7. The method for designing a liquid crystal waveguide beam scanner based on fringe field effect according to claim 6, characterized in that: In step S5, the relative increase in energy transmittance=the increase in energy transmittance / the original energy transmittance; and the relative decrease in scanning angle=the decrease in scanning angle / the original scanning angle.

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