Effect of pointing errors on combined beam power in MEMS optical phased arrays

Micro electromechanical systems (MEMS) optical phased arrays are distinguished by their ability to achieve a large steering angle and high optical gain, which makes them well-suited for space laser communication. However, there are pointing errors between the beams of each array element due to mounting inaccuracies or the need for precision of the MEMS. This will lead to a decrease in the combined beam power, which in turn affects the quality of communication. Therefore, this paper analyzes the effect of pointing errors on combined beam power in MEMS optical phased arrays. Based on the reflective diffraction of a Gaussian beam after the MEMS, the theoretical expressions for the far-field beam power in the presence of pointing errors are derived. The above expressions are then subjected to simulation and analysis. Finally, the system is built for experimental validation. The result shows that the discrepancies between the measured and simulated results are only 5.25%, 4.48%, and 2.79% for the number of array elements 2×2, 4×4, and 8×8, respectively. This paper could provide a valuable reference to the accuracy requirements of MEMS for practical applications of MEMS optical phased arrays.