Passively Q-switched Yb,Er:phosphate glass laser

The effect of thermal deformations of active elements (AEs) fabricated of phosphate glasses of two types on the mode structure and output energy of a passively Q-switched Yb, Er phosphate glass laser is studied upon longitudinal pumping of AEs by a diode laser array. A scheme of the laser resonator is proposed which simultaneously reduces the influence of a thermal lens induced in the AE on the laser radiation parameters and matches the active-medium volume with the lowest mode of the resonator when the cross section of the pump beam has nearly elliptical shape. In the passively Q-switched regime, output pulses of duration 26 ns and energy 1.4 mJ were obtained with this resonator.