Frequency Conversion in High-Pressure Hydrogen

TL;DR

This paper introduces a novel frequency conversion method using coherent anti-Stokes Raman scattering in dense hydrogen gas, offering broadband conversion without background noise, preserving photon polarization, and potentially advancing quantum communication technologies.

Contribution

The paper presents the first demonstration of frequency conversion in hydrogen gas via CARS, bypassing crystal limitations and enabling broadband, background-free quantum photonic applications.

Findings

Successful conversion from 434 nm to 370 nm

Polarization of photons is preserved during conversion

Method is broadband and background-free

Abstract

State-preserving frequency conversion in the optical domain is a necessary component in many configurations of quantum information processing and communication. Thus far, nonlinear crystals are used for this purpose. Here, we report on a new approach based on coherent anti-Stokes Raman scattering (CARS) in a dense molecular hydrogen gas. This four-wave mixing process sidesteps the limitations imposed by crystal properties, it is intrinsically broadband and does not generate an undesired background. We demonstrate this method by converting photons from 434 nm to 370 nm and show that their polarization is preserved.