Twisted rectangular Laguerre–Gaussian correlated sources in anisotropic turbulent atmosphere

Abstract

The ability to impress twist phase on random sources has led to new insights into coherence theory as well as important applications in optical tweezers and optical communications. In the paper, a new class of twisted sources named rectangular Laguerre–Gaussian correlated (TRLGC) fields is introduced based on a superposition of a mutually incoherent, tilted and displaced partially coherent beams. The analytical expressions for the cross-spectral density and the second-order moments of a TRLGC beam propagating through anisotropic non-Kolmogorov turbulent atmosphere are derived. The evolution characteristics of a TRLGC beam such as the spectral intensity, the spectral degree of coherence, and the beam quality are investigated in detail. It is shown that higher values of twist factor can significantly suppress the anisotropic beam spreading induced by the anisotropy of turbulence. Moreover, owing to the twist phase and higher-order coherence parameter, the anti-turbulence capability of partially coherent beams is further enhanced. For anticipated atmospheric communication channel conditions, a comprehensive selection of initial beam parameters, receiver aperture size and receiver capability, etc., is very important. Our work is helpful for exploring new forms of twistable sources and enriches potential applications of novel partially coherent beams in free space optical communications.