Retroreflective optical communication system

A retroreflective optical communication system in which a laser at a control station is aimed at a retroreflector at a second position or station whose reflectivity can be varied so as to impress a signal onto the retroreflected beam, and then back to the first station for detection. The communication link is such that the laser and aiming capability are at the receiving or control station and, greatly reducing the aiming and power requirements and cost at the retroreflector end of the link. The retromodulator optical communication system provides a high data rate, secure, non-jammable line-of-sight communication link between the second station, which may be a remotely piloted vehicle (RPV) and its control station. The retromodulator maybe entirely passive and thus would not give its presence away as would RF transmitting and receiving stations.