Multi Beam Scanning Method And Application Of Liquid Crystal Optical Phased Array

The liquid crystal optical phased array is a non-mechanical beam scanning control device with the advantages of small size,low power consumption,high flexibility,electronically programmable and good stability,which has wide application prospects in the fields of laser imaging radar,space optical communication,laser shaping,optical imaging and adaptive optics.At present,liquid crystal optical phased arrays mainly use progressive scan,serpentine scan,spiral scan and Gaussian scan to achieve single-beam scanning,which has the problems of slow scanning rate and low capture efficiency.Therefore,this paper carries out the research on the multi-beam scanning method and application of liquid crystal optical phased arrays.The main elements of the paper work are as follows:Starting from the basic structure of the liquid crystal optical phased array,the electrooptical characteristics of liquid crystal molecules and the law of pointing vector distribution are analyzed,the principle of spin regulation of light by liquid crystal electronically controlled halfwave sheet is clarified,the beam deflection mechanism of liquid crystal optical phased array is explored,and the cascade technology of liquid crystal polarization grids and liquid crystal electronically controlled wave sheet is further investigated,A large-angle single-beam deflection system with a beam scanning range of 10°×10° and an angular resolution of 0.67°has been designed and realized by using binary cascade..To address the problems of long scanning period and low capture efficiency of single beam,a multi-beam scanning scheme of liquid crystal optical phased array is designed,a multi-beam scanning system is built and the feasibility of the multi-beam scanning scheme is verified through experiments;the greedy algorithm is combined with the multi-beam scanning method to shorten the scanning period by optimizing the scanning sequence of multiple beams to the target;to address the problem that the greedy algorithm is prone to fall into local optimum and cannot reach the In order to address the problem that the greedy algorithm is prone to local optimality and cannot reach the global optimal solution,a multi-beam scanning model is established and the greedy genetic algorithm is combined with the multi-beam scanning method to further shorten the scanning cycle and improve the efficiency of dynamic target capture,and simulation verification is carried out.The simulation results show that the greedy genetic algorithm not only shortens the scanning cycle effectively compared with the traditional scanning method,but also improves the capture efficiency of dynamic targets.A top-down design strategy was employed to construct the FPGA-based multi-beam scanning system,which was then broken down into functional modules and written in Verilog to execute their respective functions.Questa Sim simulation was used to validate the design of each module,and the experimental platform was constructed and experiments were conducted to evaluate the impact of various scanning techniques on dynamic target capture efficiency.Verification of the algorithm’s efficacy is demonstrated by the experimental results,that the multi-beam scanning technique based on the greedy genetic algorithm not only shortens the scanning period but also boosts target capture efficiency compared with the traditional scanning methods for different number of targets,different spot radius and different target movement speed,etc.