Spectroscopic and crystal-field analysis of new Yb-doped laser materials

Crystal-field effects are very important as far as laser performances of Yb-doped materials are concerned. In order to simplify the interpretation of low-temperature spectra, two tools derived from a careful examination of crystal-field interaction are presented. Both approaches are successfully applied in the case of new Yb-doped materials, namely Ca 3 Y 2 (BO 3 ) 4 (CYB), Ca 3 Gd 2 (BO 3 ) 4 (CaGB), Sr 3 Y(BO 3 ) 3 (SrYBO), Ba 3 Lu(BO 3 ) 3 (BLuB), Y 2 SiO 5 (YSO), Ca 2 Al 2 SiO 7 (CAS) and SrY 4 (SiO 4 ) 3 O (SYS). The 2 F 7/2 splitting is particularly large in these materials and favourable to a quasi-three-level laser operating scheme. Calculations performed using the point charge electrostatic model for these compounds and using a consistent set of effective atomic charges confirm the experimental results. This should permit to use this model in a predictive approach.