OPTICAL-PROPERTIES OF RARE EARTH-DOPED ZBLAN GLASSES

An investigation has been made of the radiative and non-radiative properties of the well known ZBLAN glass composition doped with individual rare earth elements (Pr3+, Nd3+, Dy3+, Ho3+, Er3+ and Tm3+) at levels between 0.1 and 4 mol%. The optical absorption and fluorescence spectra of the samples were measured and also the lifetimes for some transitions. Using the Judd-Ofelt model, the radiative decay rates between the different levels, the lifetimes and the branching ratios were calculated. These results and comparison of calculated and measured lifetimes are discussed with respect to radiative and non-radiative rates and quantum efficiencies. The multiphonon rates below 3200 cm-1 are found to be less in ZBLAN than in other host materials (ZBLA, SiO2, YAG).