NEW DISK STRUCTURE FOR MILLION CYCLE OVERWRITABLE PHASE-CHANGE OPTICAL DISK

The overwrite cycle characteristics and environmental stability of a p hase change optical disk with a new disk structure were demonstrated. The C/N ratio was around 55dB, the erase ratio was around 25dB and the phase jitter was under 50% throughout the one million cycle overwrite test. The accelerated aging test conditions were 90 degrees C, 80%RH, for 600 hours and 70 degrees C, 80%RH for 5,200 hours. The archival a nd shelf one million overwrite cycle characteristics of phase jitter w ere stable throughout the aging test. The life expectancy of the disk is anticipated to be more than 60 years in a 32 degrees C, 80%RH envir onment.