Fabrication and optical properties of transparent Nd3+:YAG nanoceramics

The transparent Nd:YAG nanoceramics composed of nanocrystalline grains were fabricated by hot-pressing technique. Their absorption and luminescence spectra were measured. The effect of Nd concentration on absorption and luminescence spectra was studied. It was found that the concentration strongly affects the luminescence spectra appearing in decrease of the intensities of 4F3/2→4I9/2 band compared to the 4F3/2→4I11/2 band. The spectra are also significantly broadened. Additionally the Judd-Ofelt analysis was performed and the radiative lifetimes were calculated. The Ωλ decreased with increasing sintering temperature, from 1.60, 2.86 and 5.14×10−20 cm2 at 800 °C down to 0.75, 2.44 and 3.70×10−20 cm2 for 1200 °C, respectively for λ=2,4,6. The mechanism of concentration quenching of Nd3+ luminescence in YAG nanoceramics was briefly discussed.