New parametrization of spectra of Nd and Sm in glasses

The semi-empirical realization of the Judd-Ofelt theory of f{left-right arrow}f transitions has proved to be a powerful tool for the reproduction of the majority of the observed lines in lanthanide doped materials. However, the theoretical description of some of the observed transitions is beyond the framework of the standard approach. In order to describe such transitions, which in particular are forbidden and hypersensitive, Smentek and Wybourne extended the standard theory by relativistic terms and introduced a new parametrization scheme of f-spectra. This parametrization scheme, which is still one-particle but based on double tensor operators, is applied here in order to reproduce the spectra observed in Nd3+ and Sm3+ in glasses. The results of numerical calculations are compared to experimental values and to those obtained within the standard Judd-Ofelt scheme as well as its version extended by the odd rank intensity parameters.