Design of a MEMS-Mirror-based Laser Pointing Control System of Optical Transponder for Micro-satellites

Optical communication technologies are regarded as an important breakthrough for future satellite communications. Tohoku University has been developing Adjustable beam angle Small Optical TrAnsponder (ASOTA) for micro-satellites. The design concept of ASOTA is miniaturization and low power consumption. It is necessary for space optical communication to direct the laser to the ground station with a high precision. This research describes the development of a MEMS-Mirror-based Fine Pointing Mechanism (FPM). The MEMS mirror is suitable for micro-satellites because it is smaller and consumes less power than 2-axis gimbal mechanisms. FPM is a feedback control system consisting of a MEMS mirror and a Quadrant Detector. The characteristics and mathematical model of each device are described. Then numerical simulation and ground evaluation results of FPM with a simple optical system are summarized.