Fabrication, properties and laser performance of Ho:YAG transparent ceramic

Highly transparent Ho:YAG ceramic was successfully fabricated by solid-state reaction and vacuum sintering. The optical properties, the microstructure and the laser performance of the Ho:YAG ceramic were investigated. Ho:YAG ceramic with the average grain size of similar to 15 mu m was obtained by sintering at 1760 degrees C for 20 h. The in-line transmittances in the visible region and the infrared region were both over 80%. No pores, impurities and secondary phases were detected in the grains and at the grain boundaries. The 1 at.% Ho:YAG ceramic slab (1.5 mm x 10 mm x 18 mm) was end-pumped by a Tm-YLF laser at 1910 nm. The maximum output power of 1.95W was yielded with a slope efficiency of 44.19% and Tm to Ho optical-optical efficiency was 24% at 2091 nm. (C) 2010 Elsevier B.V. All rights reserved.