80×200 Gbit/s Real-time Un-repeated Transmission over 440 km with 2.9-b/s/Hz Spectral Efficiency

In this paper, we demonstrated a real-time 80×200G DWDM system in 440-km unrepeated transmission link, which is a new distance (440 km) and spectral efficiency (2.9 b/s/Hz) record of single span un-repeated DWDM system.