An optical frequency shifter based on continuous-wave pump fields

TL;DR

This paper demonstrates polarization-preserving optical frequency conversion in a hydrogen-loaded hollow core fiber using continuous-wave pumps, highlighting current efficiency levels and pathways to improve to near unity.

Contribution

It introduces a novel method for frequency conversion in a fiber-based system with potential for high efficiency in quantum networks.

Findings

Conversion efficiency at a few per mille

Identified limitations and loss mechanisms

Proposed route to near-unity efficiency

Abstract

Practical implementations of quantum information networks require frequency conversion of individual photons. Approaches based on a molecular gas as the nonlinear medium cover a wide range of the optical spectrum and promise high efficiency at negligible background. We present polarization-preserving frequency conversion in a hydrogen-loaded hollow core fiber using continuous-wave pump fields. We demonstrate conversion efficiency at the level of a few per mille, discuss various limitations and loss mechanisms, and present a route to increase conversion efficiency to near unity.