Infrared data link using a multiple quantum well modulating retro-reflector on a small rotary-wing UAV

Describes a recent demonstration of an optical data link between a small rotary-wing unmanned airborne vehicle (UAV) and a ground based laser interrogator using the NRL multiple quantum well modulating retro-reflector (MRR). MRR systems couple an optical retro-reflector, such as a corner-cube, and an electro-optic shutter to allow two-way optical communications using a laser, telescope and pointer-tracker, all on one platform. The NRL MRR uses a semiconductor based multiple quantum well (MQW) shutter capable of modulation rates above 1 Mbps. The MQW modulating retro-reflector has the advantages of being compact, lightweight, and very low power. Up to an order of magnitude in onboard power can be saved using a small array of these devices instead of the RF equivalent. In the demonstration a 400 Kbps optical link to a flying UAV at a range of 100-200 feet was shown. The device itself is capable of over 6 Mbps.