title: Experimental characterization of a 400 Gbit/s orbital angular momentum multiplexed free-space optical link over 120 m.
abstract: We experimentally demonstrate and characterize the performance of a 400-Gbit/s orbital angular momentum (OAM) multiplexed free-space optical link over 120 m on the roof of a building. Four OAM beams, each carrying a 100-Gbit/s quadrature-phase-shift-keyed channel are multiplexed and transmitted. We investigate the influence of channel impairments on the received power, intermodal crosstalk among channels, and system power penalties. Without laser tracking and compensation systems, the measured received power and crosstalk among OAM channels fluctuate by 4.5 dB and 5 dB, respectively, over 180 s. For a beam displacement of 2 mm that corresponds to a pointing error less than 16.7 μrad, the link bit error rates are below the forward error correction threshold of 3.8×10(-3) for all channels. Both experimental and simulation results show that power penalties increase rapidly when the displacement increases.
authors.forename: Yongxiong
authors.initials: Y
authors.lastname: Ren
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.forename: Peicheng
authors.initials: P
authors.lastname: Liao
authors.forename: Long
authors.initials: L
authors.lastname: Li
authors.forename: Guodong
authors.initials: G
authors.lastname: Xie
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhao
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Nisar
authors.initials: N
authors.lastname: Ahmed
authors.forename: Asher
authors.initials: A
authors.lastname: Willner
authors.forename: Martin P J
authors.initials: MP
authors.lastname: Lavery
authors.forename: Nima
authors.initials: N
authors.lastname: Ashrafi
authors.forename: Solyman
authors.initials: S
authors.lastname: Ashrafi
authors.forename: Robert
authors.initials: R
authors.lastname: Bock
authors.forename: Moshe
authors.initials: M
authors.lastname: Tur
authors.forename: Ivan B
authors.initials: IB
authors.lastname: Djordjevic
authors.forename: Mark A
authors.initials: MA
authors.lastname: Neifeld
authors.forename: Alan E
authors.initials: AE
authors.lastname: Willner