Temperature dependence of the fluorescence lifetime in Pr3+:ZBLAN glass for fiber optic thermometry

An analysis of the fluorescence decay behavior of ${\mathrm{Pr}}^{\mathrm{3+}}$ in ZBLAN glass, at different concentrations, has been undertaken, for applications of the material to fiber optic thermometry. The study has shown that with the temperature increase, the measured lifetimes of the fluorescence emission from the ${\mathrm{Pr}}^{\mathrm{3+}}$ doped glass are also seen to increase slowly. The results obtained are found not to support a simple two-level model based on the thermalization of the states involved but a new three-level model that has been introduced can explain the observed results in a very satisfactory way. The application of the work in optical thermometry is discussed and comparisons with other systems are made.