Optical Properties and Electron Paramagnetic Resonance of MnO2-Doped Fluorozirconate Glasses

We have studied luminescence and electron paramagnetic resonance (EPR) spectra of manganese-activated fluorozirconate glasses. In ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) glasses, manganese gives a green luminescence band peaking at 545 nm. Partial chlorine substitution for fluorine in the glass leads to a shift and broadening of the luminescence band. Complete BaCl2 substitution for BaF2 in ZBLAN < Cl > fluoride chloride glass increases the peak emission wavelength to 610 nm. The observed distinctions between the EPR spectra of the Mn-doped ZBLAN and ZBLAN < Cl > glasses correlate with those between their luminescence spectra. The effect of chlorine substitution for fluorine on the luminescence and EPR spectra of the fluorozirconate glass is tentatively attributed to a change in the oxidation state of the manganese ions.