Refractive index of chalcogenide glasses over a wide range of compositions

The refractive index frequency dependence in the 1–11 μm range for AsSe, GeSe and AsGeSe glassforming systems and for three- and four-component systems obtained by substitution of antimony, bismuth, tin, lead, sulphur and tellurium for arsenic, germanium and selenium, being their periodic system counterparts, is investigated. A comparison of optical constants of chalcogenide glasses with those for other optical materials by means of constructing of an Abbe-type diagram in n_2.0 ? v_2.0 coordinates is considered. The possibility of chalcogenide glass refraction calculation by means of additive formulas is discussed. It is shown that critical points on the property-composition curves coincide with structural region boundaries in all of the investigated systems. These data are considered as further experimental support for the polymer nature of chalcogenide glasses.