A 2.65-kW Yb:YAG single-rod laser

We report a continuous-wave average output power of 2.65 kW from a single Yb:YAG laser rod pumped with 9000 W from 940 nm InGaAs laser diodes. To the best of our knowledge, this is the highest average output power ever reported from a single Yb:YAG gain element. The optical-to-optical efficiency (i.e., output power to raw laser diode optical power) was 28%. We also obtained 860 W with an M/sup 2/ of 2.1 when pumping with 6000 W, obtaining 14% optical-to-optical efficiency.