Diode-pumped Er-Yb:glass laser passively Q switched by use of Co2+:MgAl2O4 as a saturable absorber

We report on passively Q-switched operation of a diode-pumped Er-Yb:glass laser with a Co2+:MgAl2O4 plate as a saturable absorber. Optical pulses with peak power exceeding 2 kW and a pulse length of 2.3 ns have been generated. Single-longitudinal-mode Q-switched operation at 1.53 mum has been obtained by use of the Co2+:MgAl2O4 plate as an intracavity etalon. A discussion of the optimal Er3+ concentration as well as optimization of the cavity design is included. (C) 2000 Optical Society of America OCIS codes: 140.3500, 140.3540, 160.5690, 160.6990.