Materials developments for write-once and erasable phase-change optical recording

Stoichiometric amorphous films of InSb or GaSb are found to have very short (< 15 ns) crystallization times when heated to temperatures close to their melting point. They can be used for write-once amorphous to crystalline optical recording. By adding Te to InSb the crystallization time can be tuned so that erasable crystalline to amorphous optical recording is feasible with a 1-microm sized circular erase spot. Carrier-to-noise ratios of more than 50 dB are achievable at compact disk (CD) recording conditions. The erasable medium allows for CD - type run - length - !imited encoding at user bit densities of < 0.6 pm/bit.