Design of nonuniform optical phased array with low side-lobe level and wide beam scanning range

We propose an improved particle swarm optimization (PSO) algorithm and utilize the peak side-lobe level (PSLL) at the steering angle as the evaluation metric to optimize antenna spacing distribution. By introducing a nonlinear inertia weight and dynamic scaling factors to enhance the global search ability of PSO. With this design approach, we effectively suppress grating lobes and mitigate the rapid degradation of the PSLL during large-angle beam scanning. After optimization, over the steering range ±60°, the PSLL of the optimized 32-channel optical phased array (OPA) ranges from 9.49 dB to 8.56 dB, and the beam width (BW) ranges from 0.34° to 0.68°. For the optimized 64-channel OPA, the PSLL ranges from 11.19 dB to 9.88 dB, and the BW ranges from 0.18° to 0.34°. This kind of OPA with low side-lobe level and wide beam scanning range will have a wide application in the fields of light detection and ranging and holography.