Fast calibration algorithm for output beams in optical waveguide phased arrays using the rotating electric field vector fitting

The continuous pursuit of higher spatial resolution in LiDAR systems necessitates the ongoing expansion of array scale in integrated optical waveguide phased array chips, which serve as a critical beam-steering component. However, this expansion significantly intensifies the complexity of initial phase calibration, while conventional calibration methods exhibit deficiencies in both calibration efficiency and beam quality. To address these issues, this paper, based on an analysis of the output optical field characteristics of a one-dimensional optical waveguide phased array, proposes a fast calibration algorithm for the output beam based on the fitted rotating electric field vector. The method achieves efficient phase calibration by applying specific phase modulation to each channel and fitting the variations in output light intensity to determine the optimal phase. Numerical simulation results demonstrate that for N=512, compared to the traditional stochastic parallel gradient descent method, the proposed fitted rotating electric field vector algorithm improves the side lobe suppression ratio by 2.9% and reduces the algorithm runtime by 70%. This approach enables comprehensive optimization of beam quality and a significant enhancement in calibration speed, all while ensuring beam pointing accuracy.