Affected by voltage quantification, manufacture technology and environment temperature, the actual deflection accuracy and diffraction efficiency of liquid crystal optical phased arrays (LC-OPA) are in error with the ideal situation when the beam deflected. In this paper, we studied the method of improving the deflection performance of LC-OPA based on stochastic parallel gradient descent (SPGD) algorithm, and choose Strehl ratio (SR) as the performance evaluation function for simulation experiments. We analyzed the influence of the disturbance amplitude δ, the gain coefficient γ and the number of periodic electrodes N on the performance optimization of the SPGD algorithm in the LC- OPA beam. Draw the conclusion: When the number of periodic electrodes N is within a certain range, appropriate adjustment of the disturbance amplitude δ and the gain coefficient γ can achieve better optimization effects, and the larger the deflection angle, the better the optimization effect. When the number of periodic electrodes N is 4, the amplitude of disturbance δ is 0.0009, and the gain coefficient γ is 0.1, the ideal optimization effect of SR of 0.82 can be achieved, which provides a theoretical basis for improving the large-angle deflection precision and diffraction efficiency of LC-OPA.
Beam steering is an important part of achieving target searching, aiming, tracking, capturing and imaging. It has important applications in the fields of new system laser radar and space laser communication. In this paper, the basic principle of optical phased array (OPA) beam steering is detailed, the development status and research results of OPA beam steering technology based on liquid crystal, optical waveguide and MEMS are introduced, and the application of OPA beam steering technology is briefly described. Finally, the prospect of optical phased array beam steering technology is prospected.