Simplified Beam Steering and Fast Error Compensation of Optical Phased Arrays by Using a Novel Weighted-Grouping Algorithm

Abstract

Optical phased arrays (OPAs) serve as pivotal components for non-mechanical beam steering and find relevance in various applications. However, they necessitate correction of optical phase errors within the antenna array, arising from fabrication imperfections in waveguides. We introduce a novel weighted group phase compensation (w-GPC) algorithm to simplify phase compensation and beam steering for OPAs but also enhances sidelobe suppression. A key advantage lies in its reduced hardware requirements, enabling phase compensation with only half or a quarter of the original number of electrodes. Simulation-based verification confirms that beam steering remains achievable even with the reduced number of phase shifts. Consequently, this minimizes the necessary electrodes on the OPA chip and significantly streamlines control circuitry. This feature is especially beneficial for large-scale OPAs comprising hundreds or even thousands of phase shifters. The w-GPC's phase compensation significantly outpaces traditional Genetic and PSO algorithms in computation speed. Applying the proposed algorithm with half controlled phases to optimize 64-and 1024-element OPAs yields impressive peak-to-sidelobe level (PSLL) enhancements, reaching up to 15 dB and 22 dB, respectively. Remarkably, PSLL remains over 19 dB even when only one sixteen of the phases are utilized to correct phase errors and steer the beam for a 1024-element OPA. These outcomes affirm that exceptional PSLL values can be achieved by great reduction in the number of control electrodes.