High-power CW and passively Q-switched laser operation of Yb:GdCa4O(BO3)3 crystal

We demonstrate efficient high-power CW and passively Q-switched operations of Yb:GdCa4O(BO3)(3) lasers. An output power of 18.2 W is generated at 1031.5 nm in CW mode, with optical-to-optical and slope efficiencies being respectively 55% and 70%, with respect to incident pump power. In passively Q-switched operation with a CO4+:YAG crystal as saturable absorber, a maximum average output power of 15.6 W is produced at a pulse repetition rate of 91 kHz, with an optical-to-optical efficiency of 44%. Low-repetition-rate Q-switched action is also realized, generating an average output power of 4.2 W at 5.7 kHz, the resulting pulse energy and duration are 737 mu J and 3.6 ns, leading to a peak power amounting to 205 kW. (C) 2015 Elsevier Ltd. All rights reserved.