Design of a Sparse Array for a One-Dimensional Non-Uniform Optical Phased Array

To effectively improve the far-field scanning range of an optical phased array (OPA), we propose a genetic algorithm using double fitness functions to optimize the array element arrangement of a one-dimensional non-uniform OPA and simulate a one-dimensional OPA with different array element numbers. The results show that the non-uniform OPA with more array elements exhibits an improved grating lobe suppression effect, and the optimized antenna array pattern exhibits improved comprehensive performance upon employing the double fitness function of grating lobe suppression and beam steering. Considering 128 array elements as an example, the sidemode suppression ratio (SMSR) exhibits a 2.8-dB improvement in the steering process, which verifies the importance of incorporating the novel fitness function of steering optimization. In addition, we further analyze the influence of manufacturing errors such as emission intensity and array position on the SMSR; it is found that the OPA obtained by simulation is sufficiently robust. Our research lays a theoretical foundation for the development of a one-dimensional non-uniform OPA sparse array.