Design Analysis of A Compensation Technique In FSO Communication System to Mitigate Atmospheric Turbulence Effect

Abstract

Free-space laser communication systems usually experience strong channel fading caused by atmospheric turbulence. To mitigate the impact of atmospheric turbulence on free-space optical links using compensation techniques including adaptive optical (AO) system as advanced technique. Its three main components have remained constant: a wave front sensor to measure distortion, a wave front corrector to compensate for the distortion and a control system to calculate the required correction and necessary shape to apply to the corrector. Optical communication schemes utilizing adaptive optical at the transmitter are proposed. Numerical simulations show that the proposed schemes can significantly reduce the channel fading. The main goal of any adaptive optical system is to show a phase correction in the arriving wave front that converts the distorted wave front into a plane wave. A free space optical AO system to mitigate turbulence-induced phase fluctuations has been implemented by using a wavefront sensorless architecture The AO system was designed to correct the first 20 Zernike modes by using two separated active mirrors: a tip/tilt corrector and a DM with 32 actuators. Also, standard deviation of the atmospheric tilt was computed, DM stroke, the residual phase variance, the turbulence strength for different telescope apertures.

Keywords

• fso
• adaptive optical(ao)
• compensation
• atmospheric turbulence