Parametric four-wave mixing using a single cw laser

TL;DR

This paper demonstrates a parametric four-wave mixing process using a single continuous-wave laser locked to a rubidium transition, generating coherent light at 420 nm with potential for efficiency improvements.

Contribution

The work introduces a novel method of generating coherent 420 nm light via four-wave mixing with a single cw laser locked to a specific atomic transition.

Findings

Successful generation of 420 nm light through four-wave mixing

Efficiency limited by absorption on resonance, with potential for improvement

Analysis of process dependence on laser intensity, frequency, and atomic density

Abstract

Four-wave mixing can be used to generate coherent output beams, with frequencies difficult to acquire in commercial lasers. Here a single narrow ECDL locked to the two photon 5s-5d transition in rubidium is combined with a tapered amplifier system to produce a high power cw beam at 778 nm and used to generate coherent light at 420 nm through parametric four-wave mixing. This process is analyzed in terms of the the intensity and frequency of the incoming beam as well as the atomic density of the sample. The efficiency of the process is currently limited when on resonance due to the absorption of the 420 nm beam, and modifications should allow a significant increase in output power.