Optical Communications Device - Retrometer

Year Published: 1963

Creator: Langley Research Center

Format: 16mm

Sound: sound

Description: Describes the retrometer, an optical communications device which is based upon the unique properties of a corner reflector, showing how one of the reflector sides is replaced with mylar film which can modulate a light beam emitted by a power source. Points out that this optical communications system is not based on electromagnetic principles and cannot therefore be detected by normal listening procedures.