400GBASE-LR4 Transmission Over Field-Deployed Fibre Link Supported by Bismuth-Doped Fibre Amplifier

We demonstrated a transmission of 4x53 GBd PAM4 signals using a bismuth-doped fibre amplifier for the first time. Transmission reach was successfully expanded by amplifying 4 CWDM signals from 1271 to 1331 nm.