Saturable absorber Co2+:MgAl2O4 crystal for Q switching of 1.34-μm Nd3+:YAIO3 and 1.54-μm Er3+:glass lasers

Saturable-absorber Q switching of a neodymium-doped YAlO3 laser at 1.34 mu m and an erbium-doped glass laser at 1.54 mu m with a Co2+:MgAl2O4 crystal was demonstrated. Q-switched 1.34-mu m pulses of 19-mJ energy and 60-ns duration and Q-switched 1.54-mu m pulses of 2.7-mJ energy and 75-ns width were obtained. The ground-state absorption cross sections of the Co2+:MgAl2O4 crystal were estimated to be (2.8 +/- 0.4) x 10(-19) and (3.5 +/- 0.6) x 10(-19) cm(2) at 1.34 and 1.54 mu m, respectively. The T-4(1)(F-4) --> (4)A(2) relaxation time of the Co2+ ion in the MgAl2O4 crystal was measured to be similar to 350 ns. (C) 1999 Optical Society of America.