First Prize at SAIP 2016

About me:
Mitch Cox

Wits EIE student Mitchell Cox was awarded first prize for his oral presentation in the PhD Applied Physics category at the South African Institute of Physics conference hosted by the University of Cape Town. Mitchell also won first prize for his poster in the PhD Photonics division on similar work.

Mitchell's PhD research is centred on free space laser-based optical communications using spatial modes of light. Spatial modes can be used for so-called Mode Division Multiplexing (MDM) to significantly increase the total information capacity of a communication system. The impending "capacity crunch" that the internet will face in coming years may be mitigated by using MDM techniques in optical fibres and free space optical communications.

The research that was presented at the conference answered the question of whether modes that contained Orbital Angular Momentum (OAM) with a uniform polarisation (scalar vortex modes) are more or less resilient to atmospheric turbulence than similar modes with a non-uniform polarisation distribution, called cylindrical vector vortex modes. Existing literature implies that cylindrical vector vortex modes are more resilient to turbulence, which would of course be beneficial to free space optical communications because they would exhibit lower crosstalk. It was found theoretically and via an experiment performed in the Structured Light Laboratory at Wits that both of these mode classes are in fact identical with regard to their performance in atmospheric turbulence.

This work has been submitted to the journal Optics Express and is awaiting review. If you are interested, you can read the paper that was submitted on arXiv: Cox, M. A., Rosales-Guzmán, C., Lavery, M. P. J., Versfeld, D. J., & Forbes, A. (2016). On the Resilience of Scalar and Vector Vortex Modes in Turbulence, 42(2015). Retrieved from http://arxiv.org/abs/1606.04336 submitted to Optics Express.