Co 2+ :LiGa 5 O 8 saturable absorber passive Q switch for 1.34 μm Nd3+:YAlO3 and 1.54 μm Er3+:glass lasers

Passive Q switching of a Nd3+:YAlO3 laser at 1.34 μm and an Er3+: glass laser at 1.54 μm was demonstrated using a Co2+:LiGa5O8 crystal as a saturable absorber. Q-switched pulses at 1.34 μm of 13 mJ energy and 90 ns duration and at 1.54 μm of 8 mJ energy and 70 ns duration were obtained. The ground state absorption cross section of the Co2+:LiGa5O8 was estimated to be (2.6±0.4)×10−19 cm2 and (2.5±0.5)×10−19 cm2 at 1.34 and 1.54 μm, respectively. The4T1(4F)→4A2 relaxation time of the Co2+ ion in the LiGa5O8 crystal was measured to be ∼130 ns.