Jitter Characteristics of Mark Edge Recording on MO Disks

Edge shift and jitter characteristics have been examined using both conventional disks and an overwritable disk with three exchange-coupled layers. Edge jitter consists of random jitter, edge shifts dependent on data patterns (thermal interference), and edge shifts independent of data patterns (fluctuations of temperature or light spot control). Write compensation is an effective means of correcting shifts depending on data patterns. The shifts which are independent of data patterns can be rendered negligible in comparison with random jitter by using an edge detection method in which the leading and trailing edges are detected independently. The results were the same for the overwritable disk. The possibility of applying edge recording in magnetooptic disk systems was thus confirmed.