Fabrication and Optical Property of Nd:Lu2O3 Transparent Ceramics for Solid-state Laser Applications

Nd3+ doped Lu2O3 crystal has been suggested to be potential gain medium for high-power solid-state lasers due to the high thermal conductivity, low phonon energy and excellent optical properties. Because of the extremely high melting point of above 2400 degrees C, great attention has been paid to the Lu2O3-based transparent ceramics considering the comparable optical properties and laser performance with single crystal. In this work, we aimed at fabricating highly transparent Nd:Lu2O3 ceramics and investigating the optical properties and laser performance. 1.0at%Nd:Lu2O3 ceramics were fabricated by two-step sintering, namely vacuum sintering along with hot isostatic pressing (HIP) method, from coprecipitated nano-powders. The microstructures of the as-prepared powder, green body and ceramics were studied. The average grain size of the HIPed ceramics is 724.2 nm. The final ceramic sample has the in-line transmittance of 82.4% at 1100 nm (1.0 mm thickness). The absorption cross-section of 1.0at%Nd:Lu2O3 ceramics at 806 nm is 1.50x10(-20) cm(2) and the calculated emission cross-section from fluorescence spectrum at 1080 nm is about 6.5x 10(-20) cm(2). The mean fluorescence lifetime, 169 mu s, of the F-4(3/2) -> I-4(11/2) was measured at the two excitation wavelengths of 878.8 and 895.6 nm, respectively. Laser performance of the annealed ceramic sample was investigated in quasi-continuous wave (QCW) condition. A maximum laser output power of 0.47 W with a slope efficiency of 8.7% is obtained by using an output coupler with a transmission of T-OC =2.0%. Briefly, laser level Nd:Lu2O3 transparent ceramics with high optical transparency and uniform microstructure have been fabricated, which are promising gain media for solid-state lasers.