Propagation characteristics of screw-edge dislocations beams in turbulent atmosphere

Abstract Phase singularity beams are closely associated with orbital angular momentum (OAM) and hold significant applications in optical communication. The screw-edge dislocations beams, a type of phase singularity beams, serve as the research object in this paper, which delves into the propagation characteristics of screw-edge dislocations beams in turbulent atmospheric conditions. The study examines the effects of turbulence intensity on the spiral spectrum characteristics and channel capacity variations during beam propagation. The findings reveal that at the source plane, screw-edge dislocations beams exhibit two OAM modes with equal detection probabilities. During propagation through turbulent atmosphere, the detection probabilities of these two OAM modes decrease with increasing transmission distance under both strong and moderate turbulence, while, at the same transmission distance, remaining equal in strong turbulence. Nonetheless, under weak turbulence, the detection probability of one OAM mode gradually increases while that of the other decreases. Additionally, the channel capacity of screw-edge dislocations beams decreases with declining inner scale of turbulence and generalized exponential parameter under strong and moderate turbulence, while the channel capacity exhibits minimal decrease with increasing transmission distance under weak turbulence. These results provide valuable guidance for the application of OAM in optical communication.