Chalcogenide

A chalcogenide is a chemical compound containing a chalcogen (oxygen, sulphur, selenium, tellurium polonium) as negative ion.

Chalcogenide glasses have special optical properties. They are opaque in visible light and transparent in infrared. They are used in many applications : rewritable (RW) optical disks, PRAM (parameter RAM) memory, xerography, night vision systems etc.