FEASIBILITY STUDY OF GE-SB-TE PHASE-CHANGE OPTICAL DISK MEDIUM FOR ONE-PASS OVERWRITE DIGITAL AUDIO RECORDING

A phase-change optical disk medium utilizing a Ge12Sb39Te49 memory film showed characteristics suitable for one-pass overwriteable digital audio disk system at a low linear velocity of 1.3 m/s. Applying the multipulse recording method, the eight to fourteen modulation (EFM) signals were successfully overwritten using only one laser beam with a small block error rate (BLER) of < 50 counts/s. The laser irradiation power was typically 13 mW for the peak power level and 7 mW for the bias level. The available cycle number was observed to be more than 10(4) cycles with a practical sufficient laser power tolerance of +/- 20%.