Passive Q-switches or saturable absorbers generate high power laser pulses without the use of electro-optic Q-switches, thereby reducing the package size and eliminating a high voltage power supply. Co2+:MgAl2O4 is a relatively new material for passive Q-switching in lasers emitting from 1.2 to 1.6μm, in particular, for eye-safe 1.54μm Er:glass laser, but also works at 1.44μm and 1.34μm laser wavelengths. Spinel is a hard, stable crystal that polishes well. Cobalt substitutes readily for magnesium in the Spinel host without the need for additional charge compensation ions. High absorption cross section (3.5×10-19 cm2) permits Q-switching of Er:glass laser without intracavity focusing both with flash-lamp and diode laser pumping. Negligible excited-state absorption results in high contrast ratio of Q-switch, i.e. the ratio of initial (small signal) to saturated absorption is higher than 10.Features: •  Suitable for 1540 nm eye-safe lasers •  High absorption section •  Negligible excited state absorption •  High optical quality •  Uniformly distributed CoApplications: •  Eye-safe 1540 nm Er:glass laser •  1440 nm laser •  1340 nm laser •  Eye-safe laser range finder