Enhancing fluorescence emission properties of Dy doped in chalcogenide glass via very small compositional modifications

It has been experimentally confirmed that the addition of very small amount, tantamount to ∼1 mol%, of the group III elements (Ga or In) in combination with alkali halides (CsBr or RbBr) into chalcogenide Ge-As-S glass significantly improves the emission properties of Dy³⁺ dopant. Preferential location of Br in the first coordination shell of Dy³⁺, which occurs spontaneously during the vitrification process, is proposed to make Dy³⁺ experience different crystal fields, reduced phonon energy and modified local refractive index. This restructuring effect as a result of such minute compositional adjustments thus enhances the optical properties of rare earth elements embedded in chalcogenide glasses, while keeping their thermal properties unaltered.