Fabrication and Property of Yb:CaF2 Laser Ceramics from Co-precipitated Nanopowders

Transparent ytterbium doped calcium fluoride ceramics (Yb:CaF2) were successfully fabricated by vacuum sintering and hot pressing post-treatment from coprecipitated powders. In-line transmittance of 5at% Yb:CaF2 transparent ceramics fabricated by pre-sintering at 600 degrees C for 1 h and hot pressing post-treatment at 700 degrees C for 2 h, reaches 92.0% at the wavelength of 1200 nm. Microstructure, spectroscopic characteristics and laser performance of the ceramics were measured and discussed. The sample shows a homogeneous microstructure with average grain size of 360 nm. Furthermore, the absorption cross section at 977 nm and the emission cross section at the 1030 nm of the ceramics are calculated to 0.39x10(-20) cm(2) and 0.26x10(-20) cm(2), respectively. Finally, the laser behavior was tested, finding a maximum output power of 0.9 W while the highest slope efficiency was 23.6%.