Free-Space Optical Communication Using Non-Mode-Selective Photonic Lantern-Based Coherent Receiver

A free-space optical communication system using non-mode-selective photonic lantern (PL) based coherent receiver is studied. Based on the simulation of photon distribution, power distribution at single-mode fiber end PL quantitatively described as a truncated Gaussian over simplex. The signal-to-noise ratios (SNRs), bit-error rate (BER), and outage probability selection combining (SC), equal-gain (EGC), maximal-ratio (MRC) Gamma-Gamma turbulence channels are analyzed compared with (SMF) multimode (MMF) receiver. We demonstrate that EGC most suitable for because has limited influence BER when used can greatly affect SC used. Numerical results show requires 6 dB less SNR than SMF 5.5 MMF 10 ?6 in moderate turbulence.