High photoluminescence in erbium-doped chalcogenide thin films

The spectral properties of the chalcogenide glasses As2S3 and As24S38Se38-doped with Er3+ are presented and discussed. Thin films were formed by thermal evaporation and the erbium doping was obtained by subsequent ion implantation. Strong Er3+ emission at 1.54 μm has been observed. The high refractive index of these chalcogenide glasses lead to Er3+ emission cross-sections (15×10−21 cm2) which are two times higher than for doped silica glass. The lifetime of the Er3+ metastable 4I13/2 energy level was measured to be 2.3 ms. This short lifetime is consistent with the high emission cross-section. Furthermore, the very low phonon energies of chalcogenide glasses lead to relatively long lifetimes of the Er3+ 4I11/2 pump level, which have been measured to be of the order of 0.25 ms. These spectral properties make this glass a good candidate for applications in the field of integrated optics.