Feasibility of Transmitting 270 Gbit/s with PAM-8 in O-band CWDM4 with IM/DD System. - Md. Sabbir-Bin Hossain; Talha Rahman; Nebojsa Stojnavic; Tom Wettlin; Stefano Calabrò; Jinlong Wei; Changsong Xie; Stephan Pachnicke (OFC, 2021)