The spectral properties of chalcogenide glass 0.7Ga(2)S(3):0.3La(2)S(3
) (Ga:La:S) doped with Er3+ are presented and discussed. Emission and
adsorption spectra and lifetimes of energy levels have been measured.
The 2.7 mu m emission of Er3+ has been observed from chalcogenide glas
s for the first time. Radiative and non-radiative transition rates are
calculated and compared with the measured lifetimes of interesting en
ergy levels. Comparing this glass with Er3+-doped silica glasses, it i
s shown that the absorption and emission cross-sections of Er3+-doped
Ga:La:S are around 2.5 times higher, radiative transitions rates are a
round five times higher due to its higher refractive index, while mult
iphonon non-radiative decay rates are around three orders lower due to
its much lower phonon energy. Furthermore, the inverse energy transfe
r process in Er3+:Ga:La:S glass may have significant implications for
the operation of Er3+:Ga:La:S devices. These spectral properties, alon
g with the higher solubility for rare earth-ions in Ga:La:S, make this
glass a good candidate for new applications.