title: Coherent optical MIMO transmission over 20 km GI multi-mode fiber by using digital coherent receiver with mode convergence unit.
abstract: We describe a coherent optical MIMO transmission experiment that employs a digital coherent receiver with a mode convergence unit, which converges higher-order mode light into the fundamental mode while maintaining the phase and amplitude information of the higher-order mode. The coherent optical MIMO transmission of two 10 Gbit/s BPSK signals over 20 km of graded-index multi-mode fiber was successfully achieved by using this mode convergence unit. We also show numerically that multi channel signals for a coherent optical MIMO transmission can be recovered by employing sufficient mode diversity, even if mode conversion occurs in the transmission fiber.
authors.affiliation: NTT Access Network Service Systems Laboratories, NTT Corporation, 1-7-1, Hanabatake, Tsukuba, Ibaraki, 305-0805, Japan. takayoshi.mori@ansl.ntt.co.jp
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Mori
authors.forename: Taiji
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tomita