Unrepeatered WDM transmission of single-carrier 400G (66-GBd PDM-16QAM) over 403 km

This paper demonstrates a record single-carrier 400 Gb/s unrepeatered WDM transmission over 403 km with 64.7-dB span loss. Using optimized amplification map with 1
^st
-order Raman amplifiers, ROPAs, and 112/150-μm
²
A
_eff
fibers, error-free transmission is demonstrated for 16×66 GBd-16QAM.