Scintillation Analysis of a 400-Gb/s Coherent FSO Feeder-Link for GEO Satellite Downlink-Like Transmission

Abstract

In this letter, we experimentally demonstrate 400 Gbps coherent transmission over a turbulent free-space optical (FSO) channel for optical feeder links using a commercially available fiber-optimized coherent transponder. Controlled atmospheric turbulence (AT) with a refractive-index structure parameter up to $C_{n}^{2} = 5.51 \times 10^{-11}{\,}\mathrm {m}^{-2/3}$ is generated within a 2 m long atmospheric chamber to assess the impact of AT on the performance of the FSO link. The AT spectra, auto-correlation functions and scintillation indices are measured for six turbulence levels, demonstrating robust coherent transmission above a receiver sensitivity of -29.5 dBm and a corresponding electrical signal-to-noise ratio of 7.5 dB.