Phase-diversity phase-sensitive amplification in fiber loop with polarization beam splitter

•A parametric amplifier system with signal gain independent of incident phase is proposed.•A nonlinear fiber and a dispersive medium in a loop configuration is employed.•The operation of the proposed system is theoretically analyzed and numerically calculated.

In this paper, we propose a parametric amplification scheme based on phase-sensitive amplification in an optical fiber. The proposed system consists of a nonlinear fiber and a dispersive medium in a loop configuration with a polarization beam splitter, where phase-sensitive amplification occurs bi-directionally. The dispersive medium shifts the relative phase between signal and pump lights, due to which the amplified signal light is always obtained regardless of the signal input phase, i.e., a phase-diversity operation is achieved, while the output phase is digitized as in conventional phase-sensitive amplifiers.