First Demonstration of Six Mode PON Achieving a Record Gain of 4 dB in Upstream

He Wen, Cen Xia, Amado M. Vel ́azquez-Ben ́ıtez, Naresh Chand, Jose Enrique Antonio-Lopez, Bin Huang, Huiyuan Liu, Hongjun Zheng, Pierre Sillard, Xiang Liu, Frank Effenberger, Rodrigo Amezcua-Correa, and Guifang Li, First Demonstration of Six-Mode PON Achieving a Record Gain of 4 dB in Upstream Transm