Optical retro communication, progress report

Our activities in the field of optical retro communication have been directed towards demonstrative links at different ranges and aim to show how mobility shall be handled. Along with the mainly experimental efforts, a study of tactical applications was carried out. Some conclusions from this study were that the retro communication is a suitable technology for links from small platforms such as UAV:s, buoys, ground units within ground sensor networks and equipment for identification of battlefield units, e.g. for discriminating friends from foes (IFF). A new laser transceiver with active laser beam pointing has been developed. Systematic tests of the technology have been initiated with a particular emphasis on atmospheric effects. Liquid crystals and drive electronics for different trials have been prepared and tested. Modulated retro reflectors have been mounted in a TV broadcasting mast for link trials with a range up to 8 km. Several stationary links have been set up for limited time periods, at a range up to 1.4 km and under various weather conditions. Focal plane arrays of semiconductor quantum wells have been evaluated for use in modulated retro reflector arrangements with the function of both detector and modulator.