Free Space Laser Communication Terminals

Free space laser communication terminals capable of acquiring and communicating over a 100 mile range at a data rate of up to 19.2 Kb/s, were developed to demonstrate the feasibility of a point-to-point semiconductor-laser communication system, and to aid in the design of future systems. The terminals are flexible enough to be utilized in a variety of scenarios, including ground-to-ground, air-to-ground, and air-to-air. The terminals will be used to address three major systems issues: initial spatial-acquisition, sustained automatic tracking, and reliable communication over extended ranges. These three issues are discussed in terms of both design goals and actual hardware implementation. The terminal's usefulness in further characterizing the link channel is also discussed.