Transporting RF signals over free-space optical links

Abstract
Free space optics (FSO) is a technology that uses modulated optical beams to transmit information line-of-sight through the atmosphere. To date, the primary focus of FSO research and development has been toward the transmission of digital signals, primarily for "last mile" applications. This paper reports the use of FSO to transport modulated radio frequency (RF) analog signals, together with an investigation of key performance measures. Results indicate minimal RF signal distortion when transmitted over FSO. The advantages of using FSO include increased security and insusceptibility to electromagnetic interference (EMI).