Optical Properties of Manganese-Activated Fluorozirconate Glasses

Abstract

We have studied optical absorption and luminescence in fluorozirconate glasses activated with manganese, which was added to the glass batch in the form of compounds of manganese in different valence states (Mn²⁺ and Mn⁴⁺). The results demonstrate that, independent of its original valence state, the manganese is present in the glasses as Mn²⁺ and Mn³⁺ ions. The 300-K luminescence spectrum of the fluoride glass contains a broad green emission band due to the Mn²⁺⁴T₁(G) → ⁶A₁ transition. Its absorption spectrum contains weak bands due to Mn²⁺ and a relatively strong, broad band of Mn³⁺. Partial chlorine substitution for fluorine leads to a redshift of the luminescence bands and absorption band of manganese. The changes induced in the spectra by chlorine substitution for fluorine are due to changes in the local environment of the manganese ions.