Phase change optical recording (PCOR) medium is considered as a potential replacement for conventional magnetic recording medium due to its large data storage and archival stability. The basic principle of PCOR is based on the r&versible switching of the structure, usually, between amorphous and crystalline states using the heat of a focused laser beam. The difference in optical reflectivity of these states, defined as optical contrast, is utilized to know the data status ('0'or'1'). For a material to be an ideal PCOR medium it.
Dr. T. Rajagopalan, “STUDY OF STRUCTURAL AND OPTICAL PROPERTIES OF AS-DEPOSITED AND THERMAL/LASER ANNEALED GeBiSe THIN FILMS”, INDIAN INSTITUTE OF TECHNOLOGY, DELHI, 2001.