Optimization Design and Demonstration of Compound-Axis APT in Airborne Laser Communication

A dual-detector and dual-axis compound-axis acquisition, pointing and tracking (APT) scheme of airborne laser communication is proposed, according to the environment and distance of communication link. And a detailed analysis and optimization design of whole optical path structure is carried out. The compound axis consists of Coarse Tracking Assembly (CTA) and Fine Tracking Assembly (FTA). CTA performances a wide range of pointing and tracking, with tracking accuracy of up to 120μrad. However, servo bandwidth of FTA is greater than 300Hz, with dynamic range of 5mrad and tracking accuracy of 4μrad. The plane-to-ground laser communication demonstration experiment is successfully completed with the BER of less than 1E-7.