Dual-crystal Yb:CALGO high power laser and regenerative amplifier

This paper reports on a high-power dual-crystal Yb:CALGO laser head with greatly reduced sensitivity to thermal lensing in the gain medium. In continuous-wave operation 23 W of power were extracted from 2% doped crystals, and tunablity between 1018 nm and 1060 nm was demonstrated. This is the highest output power reported from a bulk Yb:CALGO laser to date, as well as the demonstration of the broadest tuning range. 4 mJ pulses at 1040 nm were achieved in cavity-dumped operation with quasi-CW pumping at 1 kHz repetition rate with nearly diffraction-limited beam quality. When seeded at 1030 nm with stretched femtosecond pulses, 3 mJ were achieved.