Passively Q-switched Yb(3+) laser with Yb(3+)-doped CaF(2) crystal as saturable absorber

Passive Q-switching of a diode-pumped Yb:LYSO laser at 1060 nm with a Yb(3+) ions-doped CaF(2) crystal without the excited-state absorption (ESA) was demonstrated. An average output power of 174 mW with pulse duration of 5.6 mus and repetition rate of 27 kHz have been obtained under the unoptimized conditions. And the Q-switching conversion efficiency was as high as 51.7%.