Atmospheric effects on near-infrared free space optical communication links

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] High-bandwidth optical communication systems are increasingly in demand. As radio frequency (RF) telecommunications approach its natural limit in bandwidth efficiency and long distance transmission, novel optical telecommunication techniques such as Free Space Optics (FSO) provide a viable solution for rapid, long distance data transmission. FSO is an optical technique that uses free space as the core transmission medium. A recent trend in FSO implementation shows the laser source is typically in the near-infrared (NIR) or mid-infrared (MIR) range since infrared radiation is less affected by atmospheric interferences. This allows for very high speed data transmission speeds (on the order of Gb/s) and high bandwidth with minimal atmospheric scattering and absorption, hence more efficient transmission. FSO systems are essentially limited by the responsivity of the photodetector, many of which are not able to detect very high frequency signals at long wavelength. In this thesis, the atmospheric effects on a FSO system using NIR radiation (980 nm, 1.320 [lowercase mu]m, and 1.550 [lowercase mu]m) is analyzed and are evaluated under various atmospheric conditions.