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

Abstract

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).Index Terms-Orbital angular momentum (OAM), OAM beam, vortex generator, theoretical OAM encoder.