Improved acquisition performance of inter-satellite laser communication system through non-mechanical adaptive beam control

Laser link exhibits significant potential to be applied to establish the inter-satellite optical communication network due to its high capacity and bandwidth. However, small divergence of the laser beam brings challenges to acquire the receiver with platform vibration, which may result in an acquisition failure or long acquisition time. Previous investigations have not systematically explored the adaptive beam control technology, which is an effective solution to improve acquisition performance of inter-satellite laser communication. The related analytical model and experiments are presented in this paper. The analytical model for variable divergence scanning along different trajectories is proposed to predict more precisely the acquisition failure probability and the acquisition time. To achieve the adaptive beam control nonmechanically, the lens based on liquid crystal on silicon (LCoS) is employed innovatively in the laser communication system. The tunable divergence and improved acquisition performance are validated experimentally. The large tunable range (0.423 - 58 mrad), high stability (±4 µrad) and easy-integration of LCoS lens make it satisfy requirements of satellite. This research contributes to improve the acquisition performance of inter-satellite laser communication with adaptive beam, offering solutions for the future satellite optical network.