Rare-earth-doped multicomponent Ge-based sulphide glasses

Sulphide glasses are promising hosts of rare-earth ions for a variety of photonic applications. Their large refractive index and good infrared transparency, respectively, result in large transition probabilities and low multiphonon relaxation rates for relevant optical transitions. Ge sulphide glasses are particularly attractive due to their transparency in the visible, but rare-earths an relatively insoluble in binary Ge-S glasses. Multicomponent Ge-based sulphide glasses are good solvents for rare-earths, yielding materials with high quantum efficiency. As-containing glasses have even greater optical efficiency, which, along with density and bandgap, shows a non-linear dependence on the concentration of codopant ions.