Analyzing Beam Profile, Intensity Fluctuations, and Beam Wander with Varying Weather Conditions on a Free-Space 1550 nm Optical Communication Link

Free-space optical (FSO) communication holds the potential for data communications at high bandwidths security while minimizing size, weight, and power (SWAP). However, the effects of atmospheric turbulence on an optical beam during propagation limits and degrades communication performance and bit-error-rate. Although degradation of beam quality occurs due to many factors, typically unwanted aberrations due to fluctuations in the refractive index n along beam path causing scattering, absorption, and beam wander is the main cause [1]. Randomly distributed cells called eddies are formed in the propagating medium giving rise to turbulence as well. In this paper, we report experimental results from a 3-meter FSO data link. An intensity modulated 10 Gbps beam in the next phase will be analyzed and correlated to real time weather. We study scintillations and deviation of the beam from its original path (beam wander and spread). A phosphor-coated silicon CCD is used to record and study the beam's intensity profile.