Jitter improvement in mark edge recording for phase change optical disks with optical phase encoding

Abstract

We have developed a novel absorptivity control method for phase change optical disks for improving overwriting jitter in mark edge recording. In order to control absorptivity more easily, we have designed a disk with a small difference in reflectivity between the amorphous and the crystalline states, and with a large optical phase difference between the reflected light from those two states, which produces a high carrier to noise ratio. We have obtained remarkably reduced overwriting jitter, down to 2.47 ns from 5.69 ns for the leading edge, and this has meant greatly increased applicability of mark edge recording to phase change optical disks.