Comment on `Simulating thick atmospheric turbulence in the lab with application to orbital angular momentum communication'

TL;DR

This paper critically evaluates a recent laboratory simulation method for atmospheric turbulence affecting orbital angular momentum communication, highlighting its limitations in representing general beam-wave propagation.

Contribution

It demonstrates that the existing simulation approach primarily mimics plane-wave behavior, limiting its applicability to certain collimated OAM modes.

Findings

Simulation mimics plane-wave rather than beam-wave propagation

Limitations in representing turbulence effects on broader OAM modes

Potential constraints on the use of the method for realistic turbulence conditions

Abstract

Recently, Rodenburg et al (2014 New J. Phys. 16 033020) presented an approach for simulating propagation over a long path of uniformly distributed Kolmogorov-spectrum turbulence by means of a compact laboratory arrangement that used two carefully placed and controlled spatial light modulators. We show that their simulation approach mimics the behavior of plane-wave propagation, rather than general beam-wave propagation. Thus, the regime in which their orbital angular momentum (OAM) cross-talk results accurately represent the behavior to be expected in horizontal-path propagation through turbulence may be limited to collimated-beam OAM modes whose diameters are sufficient that turbulence-induced beam spread is negligible.