Tb 3+ luminescence in fluorozirconate glasses: indicator for homogeneous Tb 3+ distribution

Abstract

The emission spectra of Tb 3+ incorporated in fluorozirconate (ZBLAN) glasses have been measured under UV excitation for various Tb 3+ concentrations. The spectra consist of two groups of lines, one group centered around 550 nm (green) originating from the 5 D 4 level and the other around 400 nm (blue) originating from the 5 D 3 level. The ratio of the intensities of the emission bands from the 5 D 4 and those from the 5 D 3 increases for increasing terbium concentration. Below 0.2 mol% Tb 3+ , the emission is dominantly blue which implies that clustering or pair formation in these fluorozirconate glasses does not occur.