Low-loss and Low-crosstalk All-fiber-based Six-mode Multiplexer and Demultiplexer for Mode-Multiplexed QAM Signals in C-band. - Koji Igarashi; Yuta Wakayama; Daiki Soma; Takehiro Tsuritani; Itsuro Morita; Kyung Jun Park; Jaekwon Ko; Byoung Yoon Kim (OFC, 2018)