A broadband fiber-optic nonlinear interferometer

TL;DR

This paper introduces a broadband all-fiber nonlinear interferometer utilizing four-wave mixing in highly nonlinear fiber, achieving high visibility and noise cancellation, with potential applications in fiber-based sensing.

Contribution

It presents the first implementation of a broadband fiber-optic nonlinear interferometer with high phase sensitivity and noise reduction capabilities.

Findings

97% peak visibility in interference fringes

>90% visibility over 554 GHz bandwidth

Noise cancellation confirmed at dark fringes

Abstract

We describe an all-fiber nonlinear interferometer based on four-wave mixing in highly nonlinear fiber. Our configuration realizes phase-sensitive interference with 97% peak visibility and >90% visibility over a broad 554 GHz optical band. By comparing the output noise power to the shot-noise level, we confirm noise cancellation at dark interference fringes, as required for quantum-enhanced sensitivity. Our device extends nonlinear interferometry to the important platform of highly nonlinear optical fiber, and could find application in a variety of fiber-based sensors.