LAUSR

Abstract Yttrium aluminum garnet (Yb 3+ :Y 3 Al 5 O 12 ) laser ceramics doped by 5, 10 and 15 at% of ytterbium ions were obtained by reactive sintering. Optimal sintering temperature range for the formation of highly-dense transparent Yb 3+ :Y 3 Al 5 O 12 ceramics under normal recrystallization conditions was found to be T = 1750–1800 °C. The influence of Yb 3+ ions on structural-phase state, phase composition, microstructure, optical and luminescent properties of sintered samples was experimentally investigated. It was shown that lattice parameter a of Yb 3+ :Y 3 Al 5 O 12 ceramics decreases linearly with increasing of Yb 3+ concentration in a good agreement with L. Vegard’s rule, that indicates to the formation of (Y 1−x Yb x ) 3 Al 5 O 12 (х = 0.05–0.15) substitutional solid solutions. No concentration quenching of Yb 3+ luminescence was observed in Yb 3+ :Y 3 Al 5 O 12 within the 5–15 at% doping range. Quasi-CW lasing of Yb 3+ :Y 3 Al 5 O 12 ceramics was studied under diode-pumping at 970 nm. A highest slope efficiency of about 50% was obtained for 15 at%-doped Yb 3+ :Y 3 Al 5 O 12 ceramics sintered at T = 1800 °C for 10 h.