Fabrication and laser performances of Yb:Sc2O3 transparent ceramics from different combination of vacuum sintering and hot isostatic pressing conditions

In this paper we report on the preparation and laser performance of transparent 3aL% Yb:Sc2O3 ceramics by reactive sintering of commercially available powders under vacuum followed by hot isostatic pressing (HIP). Combinations of different vacuum sintering temperatures (1650 degrees C and 1750 degrees C) and different HIP treatments (1700 degrees C and 1800 degrees C at 200 MPa) were tested in order to understand how these steps influence the microstructure and thus the optical and lasing properties of the ceramic samples. All the samples showed a good optical quality. The microstructure analysis and the laser tests showed that the vacuum pre-sintering temperature is the key factor determining the quality of the samples and the laser performances. The best values of slope efficiency i.e. eta(L) = 50 % and output power i.e. P-out = 6.62 W were obtained for the sample pre-sintered under vacuum at 1650 degrees C and hot isostatically pressed at 1800 degrees C.