Manipulation of received beam for free-space optical communications of intermediate distance

For the free-space optical communications of intermediate distance, an approach to maintain the communication quality against the change of the communication distance and the unsteadiness of the attitude of the communicating partners is proposed. In this work, assuming a small body for the communicating partner, we employ the spatial light modulator instead of the conventional mechanical beam steering parts to control of the focal position of the received beam and examine the performance of beam manipulation.