The information in DVDs and Blu-Ray discs is stored in a thin layer of tellurium based materials.

By using short laser pulses with appropriate energy, the material can be reversibly switched between the crystalline and amorphous states.

The two states exhibit a pronounced optical and electrical contrast making this class of materials – often termed as phase change materials – unique.

• Phasenwechselmaterialien: Optische Speichermeien
  W. Bensch, M. Wuttig
  Chem. Unserer Zeit 2010, 44 (2), 92-107