Saturable absorber Co^2+:MgAl_2O_4 crystal for Q switching of 134-µm Nd^3+:YAlO_3 and 154-µm Er^3+:glass lasers

Abstract

Saturable-absorber Q switching of a neodymium-doped YAlO(3) laser at 1.34 microm and an erbium-doped glass laser at 1.54 microm with a Co(2+):MgAl(2)O(4) crystal was demonstrated. Q-switched 1.34-microm pulses of 19-mJ energy and 60-ns duration and Q-switched 1.54-microm pulses of 2.7-mJ energy and 75-ns width were obtained. The ground-state absorption cross sections of the Co(2+):MgAl(2)O(4) 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 microm, respectively. The (4)T(1)((4)F)-->(4)A(2) relaxation time of the Co(2+) ion in the MgAl(2)O(4) crystal was measured to be approximately 350 ns.