Progress in development of multiple-quantum-well retromodulators for free-space data links

We present an update on the progress of the development of the Naval Research Laboratory's (NRL's) multiple-quantum-well retro-modulators for compact, low-power communications. We report results for data-in-flight on a small, unmanned aerial vehicle at up to 5 Mbps, in preparation for real-time video transfer using an array of devices. This data was taken at Chesapeake Bay Detachment. We also report transference of color video using wavelet compression at 15 and 30 frames/s, at 4 to 6 Mbps in the lab, at eye-safe intensity levels. The unit is a corner cube modulator using a 980-nm shutter. A five-element array was used for the data-in-flight. First results of our 1550-nm devices are also presented as progress in a "cat's eye retromodulator." (C) 2003 society or Photo-Optical Instrumentation Engineers.