Continuous Lyman-alpha generation by four-wave mixing in mercury for laser-cooling of antihydrogen

TL;DR

This paper presents a continuous-wave Lyman-alpha laser generated through four-wave mixing in mercury, enabling laser cooling of antihydrogen atoms for fundamental physics experiments.

Contribution

It introduces a novel continuous-wave Lyman-alpha source based on four-wave mixing in mercury, suitable for antihydrogen laser cooling.

Findings

Achieved continuous Lyman-alpha generation at 121.6 nm.

Demonstrated control over phase-matching via two-photon and near one-photon resonances.

Studied the effect of beam profile on the four-wave mixing efficiency.

Abstract

Cooling antihydrogen atoms is important for future experiments both to test the fundamental CPT symmetry by high-resolution laser spectroscopy and also to measure the gravitational acceleration of antimatter. Laser-cooling of antihydrogen can be done on the strong 1S-2P transition at the wavelength of Lyman-alpha (121.6nm). A continuous-wave laser at the Lyman-alpha wavelength based on solid-state fundamental lasers is described. By using a two-photon and a near one photon resonance a scan across the whole phasematching curve of the four-wave mixing process is possible. Furthermore the influence of the beam profile of one fundamental beam on the four-wave mixing process is studied.