Low-Cost, Man-Portable Free-Space Optics Communication Device for Ethernet Applications

摘要

The requirements of modern war have imposed the need for a low-cost, small-size, high-speed, large bandwidth, deployable Free-Space Optics (FSO) system that could be used to provide connectivity between major command centers and their subordinate units. Commercially available FSO systems are bulky and expensive. A preliminary low-cost FSO system was designed, based on commercial off the shelf (COTS) components, and tested over a 5 ft. distance in a previous thesis done by Janaka P. Perera. The goal of this thesis is to improve the design and to extend the working range of the FSO. By improving beam collimation, adding precise mechanical movement and using assisting tools and techniques, the FSO network link was successfully established and tested over larger distances using 100 Mbps. The maximum distance that could be achieved, with the on-hand optics and a 1mW transceiver, was 40m. Further calculations showed that the FSO link could be established over a 340m distance by using a 3mW transmitter and a 1-inch focuser in the receiver side.