Robust coherent FSO using ultrashort pulses

In free-space optical (FSO) feeder links, atmospheric turbulence causes fluctuations that significantly degrade link performance. We present a novel communication technique aimed at mitigating turbulence-induced intensity fluctuations and phase distortions, while enabling the use of dual-polarization high-order coherent modulation schemes. The technique involves transmitting ultra-short pulses through a turbulent atmosphere using a detection scheme known as a dynamic coherent all-optical matched filter. Simulation and experiments have demonstrated proof of concept, showing a dramatic improvement of more than 8.5 dB in the link budget.