Improved SPGD algorithm for optical phased array chip phase error correction in Lidar applications

Random phase errors in silicon-photonic-based OPA (optical phased array) chips can significantly affect their output beam quality, making efficient phase error correction an important requirement for Lidar systems utilizing OPA chip technology. We report an improved ASPGD algorithm for performing OPA random phase error correction with high efficiency and accuracy, especially for large channel count designs. We successfully demonstrated the ASPGD algorithm phase error calibration capability using a fabricated 16-channel chip, and we also showed that the ASPGD algorithm has significantly faster convergence and higher cosine similarity values for the corrected output beam profile compared with traditional SPGD and genetic algorithms, especially for higher channel count OPA chip designs. We believe our work can make an important contribution to the field deployment of OPA technology for chip scale long-range Lidar applications.