Resonant second-harmonic generation at 300nm exceeding 4.5W

Continuous-wave laser sources in the 290–320 nm multi-Watt regime are of great importance for driving quantum clocks and scaling quantum computers based on Rydberg states of certain trapped atoms or ions. Current second-harmonic cavities are not suited for combining these power and wavelength requirements. Using a resonant fourth-harmonic generation approach with a Raman fiber amplifier and a new cavity design, we demonstrate up to 4.7 W of power at 302 nm with no signs of degradation over 500 h.