Ho:YAG transparent ceramics based on nanopowders produced by laser ablation method: Fabrication, optical properties, and laser performance

We fabricate Ho:YAG transparent ceramics based on nanopowders produced by laser ablation method via two approaches. Higher transmittance (82% in the infrared region) is achieved in ceramics prepared with an additional round of pre-calcining before sintering. We evaluate the average volume of the scattering centers in the ceramics and their distribution along the sample depth by the direct count method using an optical microscope and by the novel method of collinear two-photon interband photoexcitation, respectively. The laser characteristics of the 1% Ho:YAG ceramics are investigated using an intracavity pumping scheme. The slope efficiency is similar to 40% relative to the absorbed pumping power at 1.85 mu m. (C) 2015 Elsevier B.V. All rights reserved.