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.