Efficient reception of spatial light into OPA via hierarchical optimization algorithm

Integrated Optical Phased Array (OPA) provides low-cost, fast-response, and highly integrated chip-level solutions for many applications. However, its inherent phase errors reduce receiving efficiency and necessitate real-time calibration. Existing studies primarily focus on transmission, whereas relatively few have addressed reception calibration. This paper researches reception-for-transmission technology and investigates the performance of spatial beams coupling into a large-scale 1 × 256 OPA receiver based on thermal phase modulation technique. A mathematical model for coupling reception is derived for the first time, and factors influencing coupling efficiency are analyzed. An efficient hierarchical optimization algorithm (HOA) for phase calibration based on photoelectric detection is proposed. Simulation and experimental results demonstrate that the HOA enables high-efficiency light reception at normal incidence (0°) and large incident angles of ±20°. The light intensity voltage shows a near-100-fold improvement over the uncalibrated state. Compared with the conventional greedy and SPGD algorithms, the HOA enhances the average light intensity voltage to 2.9 × and 1.4 × that of the two algorithms, respectively. The HOA is well-suited for real-time efficient phase calibration in large-scale OPA systems with wide-angle reception capabilities.