$\hbox{Tm}^{3+}\hbox{:LiGdF}_{4} $ Laser, Passively Q-Switched With a $\hbox{Cr}^{2+}$:ZnSe Saturable Absorber

We demonstrate efficient passively Q-switched laser operation, based on
$\hbox{Tm}^{3+}\hbox{:LiGdF}_{4}$
and
$\hbox{Cr}^{2+} $
:ZnSe, as active medium and saturable absorber, respectively. The polarized emission was centered at 1876 nm, with pulse parameters of 13 ns (duration), 467
$\mu\hbox{J} $
(energy), and 37 kW (peak power) at a repetition rate of 350 Hz.