Spectral properties of Er 3+-doped gallium lanthanum sulphide glass

Abstract

The spectral properties of chalcogenide glass 0.7Ga 2S 3:0.3La 2S 3 (Ga:La:S) doped with Er 3+ are presented and discussed. Emission and absorption spectra and lifetimes of energy levels have been measured. The 2.7 μm emission of Er 3+ has been observed from chalcogenide glass for the first time. Radiative and non-radiative transition rates are calculated and compared with the measured lifetimes of interesting energy levels. Comparing this glass with Er 3+-doped silica glasses, it is shown that the absorption and emission cross-sections of Er 3+-doped Ga:La:S are around 2.5 times higher, radiative transition rates are around five times higher due to its higher refractive index, while multiphonon non-radiative decay rates are around three orders lower due to its much lower phonon energy. Furthermore, the inverse energy transfer process in Er 3+:Ga:La:S glass may have significant implications for the operation of Er 3+:Ga:La:S devices. These spectral properties, along with the higher solubility for rare earth-ions in Ga:La:S, make this glass a good candidate for new applications.