BROADBAND OPTICAL TRANSCEIVER STUDY.

The basic objective was to study optical transceiver techniques which minimize deleterious effects of a random atmosphere on the temporal and spacial coherence associated with a transmitted laser signal. Consideration was given to a spacific communication link between a ground terminal and a stable, ground-controlled high altitude platform terminal, possibly a balloon. The communications distance was considered to be about 20 miles slant range corresponding to an altitude of 100,000 feet. The considered transmitting and receiving techniques were capable of a minimum channel capacity equivalent to a modulation bandwidth of 100 megacyclessecond with a theoretical upper limit of a t least 1 gigacyclesecond. Also investigated were the minimum required static and dynamic tracking accuracies of the transceiver compatible with state of the art techniques.