100 kW peak power external cavity diamond Raman laser at 2.52 μm

We report an external cavity diamond Raman laser operating at 2.52 μm, pumped by a 1.89 μm Tm:LiYF4 (YLF) laser. The maximum pulse energy at 2.52 μm is 1.67 mJ for 4.4 mJ of pump, yielding a conversion efficiency of 38 %. The best slope efficiency is ~60% and the Raman pulse duration is between 11 and 15 ns for ~33 ns pump pulse duration. The peak power at 2.52 μm is >100 kW. This demonstration of a Thulium laser pumped diamond Raman laser paves the way for accessing the industrially important wavelength region of ~2.5 μm.