20.7-Tb/s repeater-less transmission over 401.1-km using QSM fiber and XPM compensation via transmitter-side DBP

We achieved record repeaterless transmission of 20.7-Tb/s over a 401.1-km link comprising hybrid spans of QSM and single-mode fibers by applying multi-channel transmitter-side digital back-propagation. We also demonstrate error-free DWDM transmission of real-time 200G channels.