Influence of atmospheric turbulence on optical communications using orbital angular momentum for encoding

Abstract

We describe an experimental implementation of a free-space 11-dimensional communication system using orbital angular momentum (OAM) modes. This system has a maximum measured OAM channel capacity of 2.12 bits/photon. The effects of Kolmogorov thin-phase turbulence on the OAM channel capacity are quantified. We find that increasing the turbulence leads to a degradation of the channel capacity. We are able to mitigate the effects of turbulence by increasing the spacing between detected OAM modes. This study has implications for high-dimensional quantum key distribution (QKD) systems. We describe the sort of QKD system that could be built using our current technology.

Orbital-angular-momentum entanglement in turbulence

“…This model has also been used to simulate turbulence in exper-imental studies. For instance, the crosstalk among OAM modes was experimentally measured [19,20], where the turbulence was simulated with a single phase screen.…”

Quantum Information with Structured Light

“…In a recent experiment, OAM modes were used for performing classical communication over a 3-km-long free-space optical link [76]. Additionally, the effects of turbulence on propagation of OAM modes, and methods of mitigating it has been a topic of extensive study lately [77,78,75,7,79,80,81,82]. In the next part, we outline our implementation of a high-dimensional QKD system based on using OAM modes.…”

Optical Orbital Angular Momentum Demultiplexing and Channel Equalization by Using Equalizing Dammann Vortex Grating

“…Especially for communication, OAM can be used as a new freedom degree of modulation/multiplexing to further increase the transmission capacity and capacity density [7]. The OAM free space optical communication, therefore, is one of the hot topics of research in recent years [7][8][9][10][11][12]. In 2010, Awaji et al first applies the OAM multiplex technology into optical communication [11].…”