Abstract

There has been recent interest in high speed variable optical attenuators (VOAs) that can work with multimode fiber. The applications for such VOAs include laser range-finding systems, instrumentation and telecommunication links using free-space optics (FSO). In the area of free space optical communication, increasing link lengths suffer from corresponding performance decreases for several reasons. Among the causes for the decrease in performance are atmospheric scintillations. These variations in optical power at the photodetector are due to changes in the index of refraction of air with changes in temperature, humidity and pressure grow larger with distance. As a result of scintillation, optical power at the detector can fluctuate.

© 2005 Optical Society of America