Coherent Free-Space Optical Communication Using Non-mode-Selective Photonic Lantern

Abstract

A coherent free-space optical communication system based on non-mode-selective photonic lantern is studied. Based on simulation of photon distribution, the power distribution at single-mode fiber end of the photonic lantern is quantitatively described as a truncated Gaussian distribution over a simplex. The signal-to-noise and the outage probability are analyzed for the communication system using photonic lantern based receiver with equal-gain combining, and they are compared with those of the single-mode fiber receiver and multimode fiber receiver. The scope of application of the communication system is provided. It is shown that the signal-to-noise ratio gain of the photonic lantern based receiver over single-mode fiber receiver and multimode fiber receiver can be greater than 7 dB. The integral solution, series lower bound solution and asymptotic solution are presented for bit-error rate of photonic lantern based receiver, single-mode fiber receiver and multimode fiber receiver over the Gamma-Gamma atmosphere turbulence channels. Simulation results show that for the considered system the power distribution of the photonic lantern has limited influence on the outage probability and the bit-error rate performance.