Tm3+:LiGd4 laser, passively Q-switched with a Cr2+:ZnSe saturable absorber

We demonstrate efficient passively Q-switched laser operation, based on Tm³⁺:LiGdF4 and Cr²⁺:ZnSe, as active medium and saturable absorber, respectively. The polarized emission was centered at 1876 nm, with pulse parameters of 13 ns (duration), 467 ?J (energy), and 37 kW (peak power) at a repetition rate of 350 Hz.