Transition probabilities of europium(III) in zirconium and beryllium fluoride glasses, phosphate glass, and pentaphosphate crystals

Eigenvectors of Eu³⁺ were obtained by a least-squares fitting procedure to the measured transitions from the two lowestJ levels to a multitude of excited levels up to 41 000 cm^-1. The Judd-Ofelt parametersΩ_t(t = 2, 4, 6) were obtained by comparison between theU^(t) calculated from the eigenvectors, and the observed oscillator strengths. Radiative transition probabilities and branching ratios were evaluated for the excited states⁵D_J(J = 0, 1, 2, 3) and⁵L₆ to⁷F_J. The agreement between the calculated and observed lifetimes and branching ratios is better in oxide glasses than in the pentaphosphate crystal and fluoride glasses. This can be understood on the basis of the higher variety of sites and hence, better averaging.