Ceramic Yb:YAG for multiwatt compact passively Q-switched lasers

Ceramic Yb:YAG samples have been investigated spectroscopically and utilized in laser experiments. Pumping with a fiber-coupled diode at 940 nm and 15.5 W absorbed power, output power up to 5.1 W with slope efficiency up to 44.3% has been achieved in continuous wave operation. The performance is comparable with single-crystal Yb:YAG in the same setup. Employing passive Q-switching with Cr:YAG saturable absorber, we obtained 4.4 W at 48 kHz, with 7-ns pulses.