Spatial Property of Optical Wave Propagation through Anisotropic Atmospheric Turbulence

Abstract

For the free-space optical (FSO) communication system, the spatial coherence of a laser beam is influenced obviously as it propagates through the atmosphere. This loss of spatial coherence limits the degree to which the laser beam is collimated or focused, resulting in a significant decrease in the power level of optical communication and radar systems. In this work, the analytic expressions of wave structure function for plane and spherical wave propagation through anisotropic non-Kolmogorov turbulence in a horizontal path are derived. Moreover, the new expressions for spatial coherence radius are obtained considering different scales of atmospheric turbulence. Using the newly obtained expressions for the spatial coherent radius, the effects of the inner scales and the outer scales of the turbulence, the power law exponent, and the anisotropic factor are analyzed. The analytical simulation results show that the wave structure functions are greatly influenced by the power law exponent α , the anisotropic factor ζ , the turbulence strength σ ~ R 2 , and the turbulence scales. Moreover, the spatial coherence radiuses are also significantly affected by the anisotropic factor ζ and the turbulence strength σ ~ R 2 , while they are gently influenced by the power law exponent α and the inner scales of the optical waves.

Novel Simulation and Analysis of Mie-Scattering Lidar for Detecting Atmospheric Turbulence Based on Non-Kolmogorov Turbulence Power Spectrum Model

“…In 2020, Wang et al proposed an IE-FBM method to generate a non-Kolmogorov turbulent phase screen, and the low-frequency and high-frequency information of the phase screen generated by this method was better when close to the theoretical value [ 6 ]. In 2021, Guan et al derived the analytic expression of wave structure function of a plane wave and spherical wave propagation through anisotropic non-Kolmogorov turbulence in a horizontal path and simulated the influence of the internal and external scale and power ratio value of turbulence [ 7 ].…”