Irradiance scintillation on laser beam propagation in the near ground turbulent atmosphere

Optical scintillation degrades beam quality as laser beams propagation in the atmosphere and increases rates of code-error for high-data-rate laser communication in the atmosphere. The scintillated irradiance depends on integrals of atmospheric turbulence strength along the propagation path. For the shorter path-length and weaker atmospheric turbulence, the integral is smaller, and the Rytov weak fluctuation theory can solve the problem successfully. However, for longer path-length and/or stronger atmospheric turbulence strength, multiple scattering events must occur and result in saturation of irradiance scintillation. The irradiance scintillation of laser beams propagation in the near ground turbulent atmosphere is investigated for the case of plane wave and spherical wave at various typical atmospheric turbulence strengths and inner scale of atmospheric turbulence. The dependence of irradiance scintillation on turbulence strength, path-length, and inner scale is presented for the plane wave case and spherical wave case. The results on plane wave case and spherical wave case are compared.