Dongdong Huang

Spectroscopic Characteristics and Laser Performance of

(Nd_xY_0.9-xLa_0.1)₂O₃ (x=0.005-0.04) transparent ceramics were fabricated by conventional solid-state processing. The radiative spectral properties of the ceramic samples were evaluated by fitting the Judd-Ofelt model with the absorption and emission data. (Nd_xY_0.9-xLa_0.1)₂O₃ ceramics have broad absorption and emission bands with a radiative decay time of 328 μs. The absorption cross section at 806 nm and stimulated emission cross section at 1078 nm are calculated to be 1.53 ×10^-20 and 5.22 × 10^-20 cm², respectively. The product of quantum efficiency and the ionic concentration (ηN) exhibited a peak value at 1.5 at% Nd³⁺ ion concentration, while the lifetime decreases dramatically from 300 μs (0.5 at% Nd) to 49 μs (4.0 at% Nd). With 1.0 at% Nd:Y_1.8La_0.2O₃ ceramics acting as a laser medium, continuous-wave output power of 1.03 W was obtained at 1079.5 nm under an absorbed pump power of 7.2 W, corresponding to a slope efficiency of 18.4%.

{\rm Nd}{:}{\rm Y}_{1.8}{\rm La}_{0.2}{\rm O}_{3}

Highly transparent Yb, Ho doped (YLa)(2)O-3 ceramic was fabricated by conventional ceramic processing with nanopowders. The absorption and emission spectra of the ceramic was investigated. The energy transfer mechanism between Yb3+ and Ho3+ was also discussed. The strong emission band around 2 mu m indicated that the Yb-Ho: (Y(0.9)0La(0.10))(2)O-3 transparent ceramic is a promising gain medium for the generation of 2 mu m laser emissions. The laser operation of Yb-Ho co-doped (YLa)(2)O-3 ceramic at 2.1 mu m is first reported.

Transparent Ceramics

The effects of Nd3+ concentration on the visible fluorescence spectroscopic properties of Nd:(Y0.9La0.1)2O3 transparent ceramics are investigated. Under 270 nm excitation, three emission peaks are observed at 396, 426, and 633 nm. When the Nd3+ concentration is increased, intensities of the peaks at 396 and 426 nm increase while the 633 nm peak become weak due to the fluorescence re-absorption effect. Broad luminescence band centered at 426 nm is observed from the fluorescence spectrum stimulated at 358 nm. The emission intensity increases with the increase of Nd3+ ion content firstly, then decreases owing to the concentration quenching of Nd3+ ions.