Proposal for the generation of continuous-wave vacuum ultraviolet laser light for Th-229 isomer precision spectroscopy

TL;DR

This paper proposes a method to generate continuous-wave vacuum ultraviolet laser light at 148.4 nm using four-wave mixing in cadmium vapor, enabling precise spectroscopy of the Th-229 isomer transition and advancing nuclear optical clock development.

Contribution

It introduces a novel four-wave mixing technique in cadmium vapor to produce narrow-linewidth VUV laser light for Th-229 spectroscopy.

Findings

Over 30 μW of VUV power generated

Narrow linewidth achieved

Potential for nuclear clock development

Abstract

We propose to generate continuous-wave vacuum ultraviolet (VUV) laser light at 148.4 nm using four-wave mixing in cadmium vapor for precision spectroscopy of the Th-229 isomer transition. Due to the large transition matrix elements of cadmium, the readily accessible wavelengths for the incident laser beams, and the high coherence of the four-wave mixing process, over 30 $\mu$W of VUV power can be generated with a narrow linewidth. This development paves the way for coherently driving the Th-229 isomer transition and developing the nuclear optical clock.