Characteristic of the 1S0 level in Pr3+:ZBLAN glass by two-step excitation

We experimentally report on the energy position, branching ratios, lifetimes and emission cross sections of the 1S0 level in Pr3+:ZBLAN glasses by two-step excitation process: 3H4 → 1D2 → 4f5d. The calculated branching ratios and lifetimes of 1S0 by the standard as well as the modified Judd-Ofelt theories are compared with the measured ones. The results by the modified Judd-Ofelt theory, which more reasonably takes into account the effects of the configuration energies on the 5d perturbations to the 4f levels, have better agreements with the experimental results. The 1S0 luminescence by another two-step excitation process 3H4 → 3P0 → 4f5d is also discussed.