title: Erbium-doped amplification in circular photonic crystal fiber supporting orbital angular momentum modes.
abstract: We propose a new orbital angular momentum (OAM) erbium-doped fiber amplifier based on a circular photonic crystal fiber, which can support a total of 18 modes (14 OAM modes) over C-band. A correction factor is proposed to modify the overlap factor, with the aim of evaluating the performance of the amplifier more accurately. We found that the confined doping profile can help optimize the differential model gain (DMG). Numerical simulations suggest that the proposed OAM fiber amplifier can provide a gain larger than 20 dB for all 14 OAM modes, with the small DMG less than 0.2 dB and the noise figure lower than 3.5 dB across the C-band.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Deng
authors.forename: Hu
authors.initials: H
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Tang
authors.forename: Lixia
authors.initials: L
authors.lastname: Xi
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhang
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Zhang