Numerical Analysis of Orbital Angular Momentum based Next Generation Optical SDM Communications System

Abstract

In this paper, we make a theoretical and numerical analysis of a transmission chain based on an Orbital Angular Momentum ({OAM}) technique in the case of ideal channel. In order to generate an {OAM} beam, we define a theoretical {OAM} encoder (vortex generator) similar to the Spiral Phase Pattern ({SPP}) in practice, converts a flat Gaussian phase front into a helix. We then multiplex several {OAM} channels, all modulated with {QPSK} streams of data and then decode specific modes and measure the overall performance in terms of signal to noise ratio ({SNR}) and bit error rate ({BER}).