Effects of atmosphere turbulence on the purity of light carrying orbital angular momentum employing Zernike Polynomials method

Employing the Zernike Polynomials method, the propagation characteristics of a Laguerre-Gaussian (LG) beam carrying orbital angular momentum (OAM) through the turbulent atmosphere are researched, we establish the random phase screens to emulate atmosphere turbulence according with the Kolmogorov spectrum model and simulate free-space propagation by virtue of the Fresnel diffraction. Intensity and phase distribution, OAM spectrum of LG beam affected by atmosphere turbulence are analyzed. The research results show that the atmosphere turbulence will lead to the spread of topological charge, the variation trend of OAM purity with distance and atmosphere turbulence intensity are obtained by calculations and simulations.