1-8 July 2022
Virtual Conference
Africa/Johannesburg timezone
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Interferometric orbital angular momentum mode detection in turbulence with deep learning

5 Jul 2022, 15:30
15m
Zoom Platform (Virtual Conference)

Zoom Platform

Virtual Conference

Oral Presentation Track C - Photonics Photonics

Speaker

Mitchell Cox (University of the Witwatersrand)

Description

Orbital angular momentum (OAM) modes are topical due to their versatility, and they have been used in several applications including free-space optical communication systems. The classification of OAM modes is a common requirement, and there are several methods available for this. One such method makes use of deep learning, specifically convolutional neural networks, which distinguishes between modes using their intensities. However, OAM mode intensities are very similar if they have the same radius or if they have opposite topological charges, and as such, intensity-only approaches cannot be used exclusively for individual modes. Since the phase of each OAM mode is unique, deep learning can be used in conjugation with interferometry to distinguish between different modes. We demonstrate a very high classification accuracy of a range of OAM modes in turbulence using a shear interferometer, which crucially removes the requirement of a reference beam. For comparison, we show only marginally higher accuracy with a more conventional Mach–Zehnder interferometer, making the technique a promising candidate towards real-time, low-cost modal decomposition in turbulence.

Level for award;(Hons, MSc, PhD, N/A)?

n/a

Apply to be considered for a student ; award (Yes / No)? no

Primary author

Mitchell Cox (University of the Witwatersrand)

Presentation Materials