High Power UV-laser for the Mu-MASS experiment
We report our first generation of high power CW UV-laser light. Successful locking of the second harmonic generation (SHG) cavity enables UV powers of up to 0.5 W.
Muonium is a hydrogen like exotic atom, consisting of a positive muon and an electron. In contrast to ordinary hydrogen, it is completely dominated by QED due to the leptonic nature of its constituents. The Mu-Mass (Muonium laser spectroscopy) experiment aims to improve the determination of the 1S-2S transition frequency of Muonium by 3 orders of magnitude external pagearXiv. Results will help resolving anomalies in the muon sector, such as the anomalous muon magnetic moment (g-2) or the so-called proton charge radius puzzle. Further, it might provide evidence towards New Physics beyond the Standard Model.
The two-photon transition will be driven by a high power CW laser in the UV regime. UV generation is achieved through frequency doubling from 488 nm to 244nm laser light, where a CLBO crystal is used as the second harmonic generation crystal (SHG).
A first setup has enabled production of UV powers up to 0.5 W. Further work is being performed to stabilize the SHG cavity, to produce higher powers and to construct a UV enhancement cavity in order to have a stable, hight power UV output.