A conical scan free space optical tracking system for fading channels

Abstract

Free space optical communication systems require robust pointing and tracking to establish and maintain lineof- sight (LOS). Atmospheric scintillation can present a challenge to the LOS tracking systems located at each end of the link. This paper describes a pointing, acquisition, and tracking (PAT) approach for single-mode fiber coupling, which was successfully demonstrated over a 5.4 km lasercom link that was subject to severe turbulence conditions. One of the primary advantages of the scheme described is its compensation for thermo-mechanical drift, which simplifies optomechanical design and allows use of simple COTS hardware. An overview of the PAT system and performance data are presented.