title: Efficient generation and multiplexing of optical orbital angular momentum modes in a ring fiber by using multiple coherent inputs.
abstract: We propose an approach to efficiently generate and multiplex optical orbital angular momentum (OAM) modes in a fiber with a ring refractive index profile by using multiple coherent inputs from a Gaussian mode. By controlling the phase relationship of the multiple inputs, one can selectively generate OAM modes of different states l. By controlling both the amplitude and phase of the multiple inputs, multiple OAM modes can be generated simultaneously without additional loss coming from multiplexing. We show, by simulation, the generation of OAM modes (OAM state |l|<3) with mode purity greater than 99%. The power loss of generating and multiplexing seven modes is about 35%. A transmitter for an OAM-based mode-division multiplexing system is proposed based on the discrete Fourier transform between the data carried by the multiple inputs and the data carried by the OAM modes. The experimental implementation of the proposed approach could be achieved by integrating ring fiber, multicore fiber, and photonic integrated circuit technology.
authors.affiliation: Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA. yanyan@usc.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Yang
authors.initials: Y
authors.lastname: Yue
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.forename: Jeng-Yuan
authors.initials: JY
authors.lastname: Yang
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Chitgarha
authors.forename: Nisar
authors.initials: N
authors.lastname: Ahmed
authors.forename: Moshe
authors.initials: M
authors.lastname: Tur
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Dolinar
authors.forename: Alan E
authors.initials: AE
authors.lastname: Willner