Synthesis of Yb:YAG Ceramics Without Sintering Additives and their Performance

High-quality 10%Yb:YAG ceramics was successfully synthesized without sintering additives such as SiO2 for the first time. Optical scattering loss of the Yb:YAG ceramics was 0.1%/cm and its transmitted wavefront distortion was /19.5 (t = 4.7 mm), which was very comparable to single crystal laser materials. Laser performance of thin disk made of this material (phi 11 x t0.15 mm) was 74.1% of slope efficiency (optical-to-optical conversion efficiency: 68.1%) and the maximum output power reached 1.8 kW. Synthesis of high-purity and high-quality YAG ceramics without using sintering additives was demonstrated for the first time to our knowledge and we can discuss the technological meaning of high-purity materials for the future.