Abstract: 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.

Abstract: An inexpensive and efficient switching device for use with optical fibers is disclosed wherein at least three optical fibers are mounted in the switching device with one of the at least three fibers mounted in a fixed magnetic block and the at least two fibers are mounted or fixed to a sliding nonmagnetic block. The blocks are held relative to a fixed base to which the fixed block is secured by means of permanent magnets and the switch is actuated by means of an electromagnet. Stops are provided for the sliding block to insure accurate alignment of the fibers to be switched during switch actuation and transmission of information in the fibers.

Abstract: Radiant energy is caused to modulate in phase and frequency in a single mode optical fiber by means of a relatively movable, spatially periodic perturbation.