Abstract:

This paper presents a prototype two-way FSO (free space optical) communication system using
a single light source. The concept involves selectively reflecting modulated laser light. Communication occurs in both directions simultaneously. Digital data in the form of modulated
laser light reaching the UAV is reflected in a corner cube retroreflector through a modulator. The modulator imposes data from the UAV onto the return beam to the ground station. This system is dedicated to communication with UAVs where diffiicult radio propagation conditions prevent the use of standard RF communication. The system practically has no radio signature and is di昀昀icult to eavesdrop on. The described system sends data only when it is illuminated by an external light source from the ground station. Return digital information is sent in the same direction from which the UAV was illuminated