Synthesis of optical Me2+,Cr4+:YAG ceramics for passive Q-switch

The purpose of this work is determines of formation patterns of opti- cal ceramics Mg2+,Cr4+:YAG and Ca2+,Cr4+:YAG as model objects promising for use as a passive Q-switch. Optical ceramics Ca2+,Cr4+:YAG and Mg2+,Cr4+:YAG was synthesized by solid-phase reaction sintering in vacuum. The influence of calcium, magnesium and chromium ion concentrations on the structure and the optical properties of ceramics Mg2+,Cr4+:YAG have been investigated. The optimized chromium concentration 0.5 at. % allows to obtain Mg2+,Cr3+:YAG ceramics with optical transmission of about 81 % at λ = 1064 nm after vacuum sintering and the absorption coefficient of about 1.4 cm–1 after air annealing. The optimized calcium concentration 0.5 at. % allows to obtain Са2+,Cr3+:YAG ceramics with an optical transmission of about 80 % at λ = 1064 nm after vacuum sintering and the absorption coefficient of about 2.4 cm–1 after air annealing.