Efficient all-solid-state Ce:LiLuF laser source at 309 nm

We report an all-solid-state laser giving 67 mW of 309 nm output when pumped with a frequency-quadrupled, all-solid-state Raman-shifted Nd:YAG laser. This efficient laser source has an optical-to-optical conversion efficiency of 41%, with respect to 289 nm conversion to 309 nm, and slope efficiencies of up to 62% (based on absorbed power).