Scintillation Index and Outage Probability of Vortex Gaussian Beams for Horizontal Links in Weak Atmospheric Turbulence

Abstract

Using the Rytov method, the off-axis scintillation index for a Gaussian vortex beam is examined in horizontal laser communication links operating in a weakly turbulent atmosphere. The performance of laser communication systems, defined in this study by the outage probability, is evaluated using the lognormal distributed intensity to find the scintillation index. The off-axis scintillation index of vortex Gaussian beams is analytically derived and evaluated in horizontal atmospheric links. The scintillation index obtained from the figures drawn versus the source size and propagation length is used to calculate the outage probability. It is found that turbulence affects vortex Gaussian beams less than non-vortex Gaussian beams. Our important finding is that the scintillation index is reduced when the topological charge increases.