Propagation dynamics and crosstalk of orbital angular momentum beams influenced by a supersonic wind-induced environmental disturbance

Abstract

Near field airflow induced by wind is an important factor influencing vortex beams propagation under airborne optical communication, and the cross-talk among different orbital angular momentum (OAM) modes occurs in OAM-based optical communication. In this paper, the propagation of vortex beams through a supersonic wind-induced random environment is investigated. The wind-induced phase model is firstly validated by wind tunnel experiment, with the phase model, vortex beams propagation under supersonic wind condition is analyzed, and the spiral spectrum distortion is discussed in detail. It is demonstrated that the larger wind velocity and boundary-layer thickness leads to the enhanced distortion and spiral spectrum expansion of OAM beams. The behavior of multiplexed vortex beams influenced by supersonic wind is also studied, and the effect of the topological charge interval is given. Our results may provide a powerful tool to estimate the effect of a random airflow environment on OAM-based communication performance under airborne condition.