Ytterbium-doped transparent ceramics based on cubic garnets are promising for thin-disk lasers. 3.6 at.% Yb:Lu3Al5O12 transparent ceramics were fabricated by a solid-state reaction at 1800 °C in vacuum using Yb:Lu2O3 and Al2O3 nanopowders produced by laser ablation and their spectroscopic properties were studied. The stimulated-emission crosssection is 2.46×10-20 cm2 at 1030.2 nm. The Stark splitting of the Yb3+ multiplets was also determined. A compact CW Yb:Lu3Al5O12 ceramic laser pumped by a fiber-coupled 968 nm InGaAs laser diode generated 5.65 W at ~1031 nm with a slope efficiency of 67.2%. Using quasi-CW pumping, the peak power reached 8.83 W.
In this work we report on the results of synthesis and investigation of Fe2+:MgAl2O4ceramic samples. Nanopowders with small average particle size of ~ 18 nm were used for the preparation of the samples. It has allowed to synthesize the ceramics with an average grain size of 300–400 nm at a temperature as low as ~ 1200 °С. It was shown that the Fe ions occupy tetrahedral sites of lattice with a mandatory valence equaled to 2 when the content of iron in the samples of magnesium aluminate spinel is higher than 1 wt.%. Transmission of radiation in the samples increased with an increase in wavelength due to the reduction of Rayleigh scattering caused by pores. It was determined that the transmission of radiation in the samples at strong and weak laser radiation remains constant in a temperature range from -164 °С to+22°C.