Research And Implementation Of Laser Scanning Based On OPA

Solid-state lidar is a new type of lidar without mechanical structure.The optical phased array is the core component of the new type of solid-state lidar,and the scanning circuit and system of the optical phased array are important components to realize the fast real-time scanning of the lidar.This thesis mainly discussed the research on the offline closed-loop calibration algorithm of the optical phased array characterization,online real-time scanning strategy,etc.,and completed the design and verification of the scanning circuit and system.The thesis carried out the research of the optical phased array scanning system.This system is mainly composed of system control module,interactive module and synchronous output module.Among them,the system control module is mainly responsible for the con-trol of the optical phased array scanning system,and its core is the data processing module,which is responsible for data processing and storage? the interactive module mainly real-izes the communication function between the system and the outside,and has the ability to transmit data and instructions? The phased array is controlled by multi-channel parallel drive signals.These signals must be kept highly synchronized.The synchronous output module designed in this thesis uses the method of combining parallel multi-channel DAC with operational amplifier to solve the problem and realize the high-precision synchronous output of multi-channel signals the closed-loop calibration algorithm for optical phased array is deeply studied in this thesis,including traditional optimization methods such as simulated annealing algorithm and particle swarm algorithm,as well as the stochastic parallel gradient algorithm adapted to the optical phased array.Through simulation analysis,stochastic parallel gradient al-gorithm has better performance than particle swarm algorithm in terms of convergence speed and global optimal solution.In the stochastic parallel gradient algorithm,when the disturbance amplitude parameter ?=0.65 and the gain coefficient ?=4,the optimal solu-tion close to the theoretical value of the side lobe suppression ratio can be obtained.and the optimization algorithm based on this parameter can complete he characterization of optical phased array with high quality..The realization and verification of scanning circuit and system are completed in this thesis.On the system verification platform,the basic electrical performance indicators of the design are firstly verified through static tests? then,the off-line closed-loop calibration algorithm is used to characterize the optical phased array at multiple scanning angles to ob-tain the optimal scanning signals at different scanning angles.Finally,store the calibrated optimal scan signal in the system control module of the scanning circuit,the optimal scan-ning signal obtained by calibration is stored in the system control module of the scanning circuit,and online real-time scanning is carried out.By collecting the equivalent far-field optical path information composed of lens and infrared CCD,the fast scanning function of the scanning circuit and system for optical phased array is verified.