Microstructure and optical properties of transparent Nd:GAGG ceramics prepared via solid-state reactive sintering

Transparent polycrystalline NdxGd3-xAl3Ga2O12 (Nd:GAGG) ceramics were prepared via solid-state reactive sintering from a mixture of commercial Gd2O3, Al2O3, Ga2O3, Nd2O3 and 0.05wt.% ZrO2 powders at 1650 °C. Fully dense ceramics were obtained for all samples with different Nd2O3 doping level. Uniform microstructures with average grain size of about 20 μm were observed in the ceramics, while no secondary phase was detected. Optimum transmittance of as high as 77% in near-infrared bands, which is close to its theoretical value of 81.1%, was achieved in the 0.8 at.% Nd:GAGG ceramics. The spectroscopic properties of the Nd:GAGG transparent ceramics were also investigated. Absorption cross-section of the 0.8 at.% Nd:GAGG ceramic at 808 nm is about 4.1 × 10−20 cm2. The emission cross-section at 1063 nm is about 1.8 × 10−19 cm2.