100 Gbit/s Ethernet technologies have been verified and standardized and 400 Gbit/s Ethernet and OTN standards become the next focus of concern.This paper discusses the relevant technologies
such as 2SC-DP-16QAM
coherent-detection array
for 400 Gbit/s Ethernet and OTN optical modules on the basis of the current 100 Gbit/s standard.