High-power passively Q-switched Yb:YCa4O(BO3)3 laser with a GaAs crystal plate as saturable absorber

We report on efficient high-power passively Q-switched operation of a Yb:YCa4O(BO3)(3) laser with a GaAs crystal plate acting as the saturable absorber. An average output power of 5.7 W at 1032 nm is generated at a pulse repetition rate of 166.7 kHz when the incident pump power is 26.8 W, with a slope efficiency determined to be 24.5%. The averaged pulse energy achieved is roughly 30 mu J and is increased to about 40 mu J when the output coupling used changes from 30% to 50%, while the shortest pulse width is measured to be 153 ns. (C) 2015 Optical Society of America