Beam Optimization Method For Silicon Based Optical Waveguide Phased Array

Optical waveguide phased array is a new laser scanning technology,which is widely used in unmanned driving,laser radar and other fields because of its high accuracy,good stability and strong anti-jamming ability.In recent years,with the development of silicon-based photonic technology,silicon-based optical waveguide phased array has become a hot research area.However,due to the limitation of current technology preparation,the gate lobe in the beam is generated,which interferes with the recognition of far-field targets.Therefore,it is very important to study the method of beam optimization.The main research contents of this paper are as follows:Firstly,based on the basic principle of phased array,the scanning principle and system structure of silicon-based optical waveguide phased array are studied.The position and condition of gate lobe generation in the far field intensity distribution of silica-based optical waveguide phased array are analyzed.The effects of uniformly spaced phased array and non-uniformly spaced phased array on it are studied.The inhibition effect of several probability density distributions on the gate lobe was compared.Aiming at the problem that the non-uniform interval structure is not easy to manufacture,the concept of the non-uniform array composed of uniform subarray and the uniform array composed of non-uniform subarray is put forward to find some regularity on the basis of the non-uniform interval.Second,for optimizing the configuration of the random array yuan interval,in order to achieve the grating lobe suppression effect,the application of particle swarm optimization(PSO)algorithm for phased array array yuan interval optimization,and in the case of multiple iterative particle swarm algorithm easy to fall into local optimal value of the defect,gives the optimization method based on pattern search method,and the two kinds of algorithm and two seeds array concept put forward by the combination.Thirdly,the two algorithms are compared with the two algorithms combined with the subarray.The results show that the two algorithms can suppress the PSLL below-4.5dB,and the two algorithms combined with the structure of subarray can suppress the gate flap to a certain extent.Finally,in order to further improve the suppression effect on the gate flap,a PSO pattern search algorithm based on the combination of particle swarm optimization algorithm and pattern search algorithm is proposed,which has the advantages of better global performance and fast iteration rate and accurate local optimization.The simulation results show that,compared with PSO and pattern search method,the PSO algorithm can suppress PSLL below-10 dB in the far-field light intensity distribution of silicon-based waveguide phased array under the condition of multi-angle deflection,and the gate flap suppression effect and convergence efficiency are better.