The influence of CsBr addition on optical and thermal properties of GeGaS glasses doped with erbium

The influence of the addition of CsBr on the optical and thermal properties of GeGaS glass doped with Er has been being investigated. We find that the addition of CsBr into GeGaS glass leads to some improvements in the radiative properties of Er3+ ions in this glass system. The GeGaS–CsBr glasses demonstrate much longer radiative lifetimes and stronger photoluminescence for \(^4\hbox{I}_{13/2} \rightarrow{^4\hbox{I}}_{15/2}\) and \( ^2\hbox{H}_{11/2} \rightarrow{^4\hbox{I}}_{15/2}\) transitions in Er3+ ions. Very low Judd-Ofelt parameters and sharp Er3+ absorption spectra with multiple peaks suggest the presence of microcrystals. All optical parameters are strongly influenced by the interplay of Ga and CsBr. The glasses studied have been characterized by their basic glass transformation temperatures. The addition of CsBr into GeGaS glass keeping the ratio between CsBr and Ga close to unity is favorable for the incorporation of larger amount of Er. The experimental results are discussed in terms of structural local arrangement induced by CsBr addition.