A 10.6 MICROMETER LASER COMMUNICATION SYSTEM FOR TERRESTRIAL USE

Abstract

This paper reports the development of an experimental type 10.6 μm laser communication system consisting of a transmitting terminal and a receiving terminal designed to operate one way over a nominal five mile terrestrial path. The system will provide a 5 Mbit/sec digital data channel utilizing intra-cavity optical frequency modulation, or frequency shift keying modulation format. It uses optical heterodyne detection with a mercury cadmium telluride detector operating at a temperature of 77°K and an i.f. frequency of 30 MHz. Since the system operates from fixed (non-mobile) terminals, acquisition and alignment procedures are simplified. Predicted performance in rain and fog is discussed and compared with a limited amount of actual data.