The paper describes the design of an infrared transmitter and receiver for communication over 1000 feet typical distance. The purpo.se of the system was to circumvent obstacles in the construction of the closed circuit television systems, and it has been successfully used for that purpose in a number of applications. The authors show calculation of path characteristics which determine fade margin requirements and the level of path dependent noise. They describe experimental verification of the calculations on a 1021-foot test path. Part of the paper describes the pertinent characteristics of the Gallium Arsenide Transmitter diode and the receiver photodiode, especially with respect to bandwidth and linearity. The optical system design is described in detail, including tolerances on the aiming system and the mechanical support of the diodes. Some of the measurement_ techniques developed to insure performance of manufactured systems are described, including techniques for power measurement and alignment.