Intensity and effective beam width of partially coherent Laguerre-Gaussian beams through a turbulent atmosphere.

Abstract

Propagation properties of partially coherent elegant Laguerre-Gaussian beam (PC-eLGB) and partially coherent standard Laguerre-Gaussian beam (PC-sLGB) through the turbulent atmosphere are studied. Analytical formulas for the intensity and effective beam width (EBW) of the PC-eLGB and PC-sLGB through the turbulent atmosphere are derived based on the extended Huygens-Fresnel principle. The propagation properties of PC-eLGB and PC-sLGB through the turbulent atmosphere are studied numerically and comparatively. It is shown that the intensities of the PC-eLGB and PC-sLGB are less affected by the turbulent atmosphere than the fully coherent Laguerre-Gaussian beam. The spreading (EBW and divergent angle of the far field) of PC-eLGB and PC-sLGB with the different mode orders (m,n) is slower in the free space than in the turbulent atmosphere, and the PC-sLGB spreads more rapidly than the PC-eLGB through the free space and the turbulent atmosphere. The study results will be useful for free space optical communications.