Research And Implementation Of Optical Phase Control Technology Based On Wave-Front Sensorless

Optical phase control technology that can correct the phase error of the transmitted beam is one of the hot and frontier research directions in the fields of adaptive optics and beam coherent combining.The wavefront sensorless optical phase control technology has the advantages of light weight,small size and simple structure in the field of laser communication,and has been rapidly developed in recent years.The phase control algorithm based on various optimization ideas in the field of optimal control directly affects the important performances such as the convergence stability,control bandwidth and control accuracy of the system,and is one of the key technologies in the wavefront sensorless optical phase control system.This thesis focuses on the research on the optimal design of the optical phase control algorithm based on the sensorless.Through the research methods of theoretical analysis,simulation analysis and verification,and experimental verification,the following main research contents are completed:Firstly,this thesis analyzes the research status of optical phase control technology at domestic and foreign.With the continuous development of technology,a variety of optimization algorithms have appeared in the field of optical phase control.One of the more commonly used and better phase compensation algorithms is the Stochastic Parallel Gradient Descent(SPGD)algorithm.Taking the traditional SPGD algorithm as the starting point,the thesis analyzes the control compensation principle of the algorithm in detail from the theoretical aspect,and combines the simulation analysis to study the main factors affecting the control effect of the traditional SPGD algorithm: disturbance step size and gain coefficient.Through the simulation analysis and comparison,the ways that these two main parameters affect the control effect of the algorithm are sorted out.Secondly,aiming at the two main parameters that affect the control effect of SPGD algorithm,an optimization algorithm is proposed to deal with these two aspects,namely SPGD algorithm based on random size of perturbation step size and gain coefficient optimization SPGD algorithm based on Ada Max algorithm.Then,the two SPGD optimization algorithms are simulated and analyzed to verify their feasibility and effectiveness in compensating the phase error.Through the simulation comparison with the traditional SPGD algorithm,the improvement of the control effect of the SPGD optimization algorithms is shown.Finally,based on the FPGA hardware platform,the optical phase control module is developed,and the Verilog program based on the traditional SPGD algorithm and the SPGD optimization algorithms idea is designed and implemented,and the actual optical phase control system experimental platform is built to verify the feasibility and effectiveness of optimization algorithm scheme designed in this thesis.The experimental results show that the system performance evaluation functions of the SPGD algorithm and the SPGD optimization algorithms in the closed-loop phase-locked state are 11.4,13.2,and 17.9 times higher than those in the open-loop state,respectively.Compared with the traditional SPGD algorithm,the SPGD optimization algorithms based on this thesis improves the phase-locked control effect,and meets the requirements of the main development indicators of the system.