Near-diffraction-limited passively Q-switched Yb:Y3Al5O12 ceramic lasers with peak power >150kW

Abstract
Laser-diode pumped nearly diffraction-limited beam quality ( M 2 < 1.05 ) , high peak power, subnanosecond passively Q -switched Yb : Y 3 Al 5 O 12 ceramic miniature laser with Cr 4 + : Y 3 Al 5 O 12 ceramic as saturable absorber has been achieved. The slope efficiency is as high as 36% for 80% initial transmission of Cr 4 + : Y 3 Al 5 O 12 ceramic. The pulse width of 335 ps and peak power of over 150 kW at repetition rate of 5 kHz were obtained. Laser oscillates at single-longitudinal-mode oscillation and wide-separated multilongitudinal-mode oscillation due to the combined etalon effect of the Cr 4 + : YAG thin plate and thin glass plate as output coupler.