Optical coupling performance using a fast-steering mirror to mitigate angle-of-arrival fluctuations in a 1km laser link

We present the characterization and performance analysis of a fast-steering mirror (FSM) system tested over a short-range laser propagation and detection system, as a possible solution to mitigate the unwanted effects induced by the atmosphere on a propagating laser beam. The system’s performance is tested under controlled turbulence conditions in the laboratory by means of a flat surface heater and forced lateral wind for a propagation distance of 3 meters. Lab results demonstrate that the FSM significantly reduces beam wander, as measured by both a position sensing device and a point intensity detector. We observe a 100% increase of the coupled optical power and a scintillation reduction to a fourth of those observed in the uncontrolled optical link. This system is currently being installed in the outdoor testbed to evaluate the performance over 1km.