Distortion Compensation for Orbital Angular Momentum Beams: From Probing to Deep Learning

Beams carrying orbital angular momentum (OAM), has attracted wide interests recently, due to their favorable potential in communications, optical tweezers, remote detection, etc. However, distortion will come once OAM beams propagate through inhomogeneous media like atmospheric turbulence. Such distortion will broaden the orbital angular momentum spectrum, thus introduce interchannel crosstalk. These phenomena will adversely affect practical applications, for instance, the rising bit-error-rate in OAM-based data transmission. Therefore, distortion correction for OAM beams, an important means to improve the robustness of OAM beams when propagating in atmospheric turbulence, must be developed. In this paper, we overview recent advances on distortion compensation of OAM beams, including the influence of atmospheric turbulence on OAM beams, and multiple wavefront correction schemes. In addition, toward the engineering realization of OAM based free space data-transmission, we propose to apply TSVMD-AR model to predict atmospheric turbulence, and expect to further improve the distortion correction efficiency.