Non-uniform Yb-doped ceramic laser gain media: shaping and performance

Yb-doped transparent ceramics are of interest for high-power and high-repetition-rate solid-state lasers. While for the production of uniformly doped Yb:YAG the material of choice is mostly a single crystal, the fabrication of single-crystal components with non-uniform dopant distribution is not trivial and significantly increases production costs. Ceramic manufacturing techniques, on the other hand, offer a variety of possibilities to produce such components at the green stage without the necessity of expensive post-processing and bonding. In the present work we discuss the production of structured Yb-doped transparent YAG ceramics and their laser performance. Different shaping techniques were tested and the resulting microstructure and optical properties are compared. Laser characterization was performed in an end-pumped cavity in QCW regime with different duty factors. Advantages of controlled dopant distribution are shown on laser emission under increasing thermal load. Support from the Italian Ministry of Defence under PNRM, Contract No. 8723 (CeMiLAP) is acknowledged.