2016 年 124 巻 4 号 p. 313-320
Highly transparent Lu2O3 ceramics with and without Nd3+ and Eu3+ dopants were fabricated by spark plasma sintering using a two-step pressure profile. A transmittance at 1080 nm for the Lu2O3 ceramics sintered by as-received powders at a pressure of 100 MPa was 57%. By sintering ball-milled Lu2O3 powders with 0.2 mass % LiF at a preloading pressure of 10 MPa, final pressure of 100 MPa, heating rate of 0.17 K s−1, and sintering temperature of 1723 K, the transmittance at 1080 nm of the Lu2O3 ceramics reached 80–82% after annealing in air, i.e., nearly 100% of the theoretical value for no scattering. Finally, laser oscillation was demonstrated using 1 at.% Nd3+:Lu2O3 transparent ceramics at 1076 and 1080 nm wavelengths, e.g., laser output of 0.2 W and slope efficiency of 14% for straight-cavity configuration.