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

Crystal-held 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 Ca3Y2(BO3)(4) (CYB), Ca3Gd2(BO3)(4) (CaGB), Sr3Y(BO3)(3) (SrYBO), Ba3Lu(BO3)(3) (BLuB), Y2SiO5 (YSO), Ca2Al2SiO7 (CAS) and SrY4(SiO4)(3)O (SYS). The F-2(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.