Progress and issues of phase-change erasable optical recording media

Abstract

Recent progress in realizing practical media for phase-change reversible optical recording is described. Key attributes required of the media and the material science which underlie them are discussed. These include: (1) the kinetics of crystallization and amorphization, (2) chemical and data stability, (3) reversibility, and (4) readout signal-to-noise ratio. The crystallization kinetics of recording media is discussed using two examples: (GeTe) 0.85Sn 0.15 and the pseudo-binary InSbGaSb stoichiometric compound system. A discussion of the recorded signal strength, sources of media noise and resulting signal-to-noise ratio is presented. Non-uniform optical index of refraction was shown to increase media noise. Methods to reduce the effect of media noise are presented.