Enhancing Laser Damage Resistance of Co2+:MgAl2O4 Crystal by Plasma Etching

Co2+:MgAl2O4 crystals are successfully used as passive Q-switches within the cavity of erbium glass lasers. Their limited resistance to laser radiation might also put constraints on generated output peak power. Usually, polishing optical substrates induces a contaminated Beilby layer and damages subsurface layer, which leads considerably lower obtained surface. Low-energy oxygen plasma etching using different depths 50, 100, 250 400 nm was performed polished crystals. The surface morphology by atomic force microscopy, transmission spectra, structure electron microscopy LIDT (R(1)-in-1) 1540 nanosecond pulses were analyzed. It demonstrated that substantially increased initial crystal LIDT. allowed removal damaged almost maintained roughness. presented results good potential for obtaining highly laser-damage-resistant high-power applications.