Use of Co²⁺:MgAl₂O₄transparent ceramics in passive Q-switching of an Er:Glass laser at 1.534 μm

We present the implementation of Co2+:MgAl2O4 transparent ceramics as passive Q-switching elements in an Er:Glass laser at 1.534 μm. Linearly polarized pulsed output was obtained by Brewster angle inclination of the material Q-switching plate relative to the laser axis. Separate pulses were ∼105 ns long (FWHM), exhibiting ∼6.2 kW peak power at near TEM00 quality. Several fundamental sample properties important for laser intracavity operation were measured; thermo-optic coefficient dn/dT = ( - 3.8 ± 1) × 10-5°C-1, thermal lensing factor L-1d(nL)/dT = 2.59 × 10-5°C-1, linear expansion coefficient α = (3.9 ± 0.6) × 10-5°C-1, polarizability thermal coefficient φ = (7.2 ± 2.2) × 10-5°C-1, and damage threshold ∼6.5 J/cm2.