Research And Implementation Of The Liquid-crystal Phased Array

Liquid-crystal-based phased array using phased array technology is a programmable optical device. When the voltage is applied on the cell phased array liquid crystal, the beam wavefront phase is modulated under the action of birefringence of liquid crystal Liquid-crystal-based phased array. The beam scanning, focus, beam splitter, wavefront correction and so on, is realized. Liquid-crystal-based phased array is used as the optical properties of optical devices with electric controllable, its advantages of low driving voltage, no mechanical rotation, low power consumption, light weight,easy to change the diffraction angle, have important applications in many fields.Such as the use of electronically controlled liquid crystal binary grating for the incident laser beam deflection of radiation, which can be used for the analysis of the modulation frequency, incident laser radiation pattern and other information;the optical path distribution of liquid crystal binary grating can be written, the phase modulation of the incident light, it has the application potential in many aspects, projection display, optical switch optical processing, detection of diffractive optics, laser beam direction and tracking, atmospheric turbulence correction etc..Based on the traditional periodic Liquid-crystal-based phased array, a method that the rough scanning layers sub array and accurate scanning multilayer composite to model Monolithic blazed grating has been proposed to solve shortcomings that the periodic blazed grating the limited number diffraction angle of unable to achieve accurate scanning. The circuit implementation and experimental test, can improve the scanning precision without loss of diffraction efficiency. In addition, the liquid crystal cell structure is for Liquid-crystal-based phased array, simulation of the liquid crystal director of two-dimensional distribution to analysis of the phase distortion, the factors influencing the performance of the Liquid-crystal-based phased array, improve the quality of Liquid-crystal-based phased array.My specific work is as follows:Firstly, this paper establish structure model based on the principle of liquid crystal phase grating with binary optics and wave optics, liquid crystal director deduced theoretical formula calculation, applying different voltage of liquid crystal phased array diffraction efficiency and diffraction angle, and the use of Matlab simulation calculation of diffraction efficiency, diffraction angle,phase delay performance. Based on periodic grating are deduced on the multilayer blazed grating compound formula one layer of Monolithic blazed grating. Simulation of the composite Monolithic blazed grating can achieve precise scanning, and not to reduce the diffraction efficiency.Secondly, electric field edge effect reshaping the director distribution in the Liquid-crystal-based phased array, research considering the director two-dimensional distribution factors such as electric field edge effect and the liquid crystal molecules in the simulation. The liquid crystal molecules in interaction of multielectrode under the director with the electrode parallel direction and box thickness direction is considered. It has improved the performance of Liquid-crystal-based phased array.Finally, the structures of the liquid crystal driving circuit has been designed. Simulation data is used in a Liquid crystal based phased array and Liquid crystal based phased array results is tested. For large data calculation, the paper also presents a Matlab data simulation + PSoC chip controlling + external FLASH storage method to generate real-time data. compared with the traditional method which data calculation requires a PC or Microcontroller, the new method can generate code faster and realize the high speed angle scanning.