Propagation Characteristics of the Vortex Beam with OAM in Inhomogeneous Atmospheric Turbulence

Based on the extended Huygens-Fresnel principle and the second moment definition of Wigner distribution function, the propagation characteristics of vortex beams (l=1) in inhomogeneous atmospheric turbulence are studied. The M² factor and the expression of beam expansion are derived and simulated. The results show that the initial spatial coherence length, beam waist, beam wavelength, zenith angle and inner scale of turbulence have great influence on the beam propagation quality. Within a certain range, reducing the coherence length, zenith angle and beam waist radius, and increasing the wavelength and inner scale of the turbulence can effectively improve the beam propagation quality. Compared with the electromagnetic-Gaussian Schell model array beams and partially coherent hollow beams, the vortex beam with OAM are less affected by atmospheric turbulence and more conductive to the effective transmission of information. In the free space optical communication (FSO), the electromagnetic Gaussian vortex beam is adopted widely because of high stability.