The invariance and distortion of vectorial light across a real-world free space link

Abstract

Vectorial structured light, where the polarization is inhomogeneously distributed in space, has found a myriad of applications in both 2D and 3D optical fields. Here, we present an experimental study of the invariance and distortion of vectorial light through a real-world medium of atmospheric turbulence. We show that the amplitude and polarization structure are both severely distorted by the turbulent medium, yet the non-separability of these two degrees of freedom remains invariant. We monitor this invariance under a range of beam types and atmospheric conditions, over extended time periods, revealing the unitary nature of atmospheric turbulence in our experiment. Our results provide conclusive evidence that invariance and distortion are not mutually exclusive and that the degree of classical entanglement remains unaltered through such channels, and will be of interest to the large community interested in classical and quantum communication in free space.

Globalization in Photonics Research and Development

“…Mitchell Cox founded this laboratory in collaboration with Ling Cheng [https://www.wits.ac.za/oclab]. Cox's primary focus is structured light in turbulence and the use of machine learning to model the effects of turbulence on laser beams [59], [60], with research looking into low-cost free-space optical communications [61]. Ling Cheng's expertise lies in digital communications and hybrid systems that combine visible light with power line communication [62], [63].…”