Phase-Change Optical Disks for a High Data Transfer Rate

Abstract

We studied a phase-change optical disk structure suitable for high linear velocity, red laser source, and mark edge recording conditions in order to realize high data transfer rate recording. On the conventional disk with a metal reflective layer suitable for pit position recording, it was found that the increase in overwrite jitter at low linear velocity conditions is small because “preceding crystallization” functions effectively. It was proved that absorption control between amorphous marks and crystalline erased area is indispensable for high linear velocity conditions. Based on these studies, we designed an absorption-controlled disk with a Si reflective layer and confirmed low overwrite jitter at a wide range of linear velocity conditions up to 17.4 m/s.