Abstract: A free-space optical transceiver includes a repositionable mirror for receiving and sending light beams with another transceiver. To properly align the light beams, the position of the mirror is determined in using a position sensor. The position sensor is mounted within a base substructure that is coupled to a steerable mirror substructure containing the mirror. The position sensor reflects sensor light off of the mirror to determine the position of the mirror along two different axes. The position sensor includes an optical element for shaping the sensor light. The components of the position sensor are mounted to the base substructure such that alignment of the position sensor is not required. Further, by coupling the position sensor to the base substructure and not the steerable mirror substructure, the moment of inertia and center of gravity of the steerable mirror substructure is improved, thereby improving the steering responsiveness of the mirror.