15 Gbit/inch/sup 2/ areal density optical disk using the DWDD medium with blue LD recording

Abstract

We developed a new layer structure of domain wall displacement detection (DWDD) optimized for a blue laser diode (LD) and confirmed that acceptable characteristics could be obtained. We tested readout and recording with a blue LD on this DWDD disk and confirmed that the jitter did not exceed 15% for bit lengths longer than 0.125 /spl mu/m at the track pitch of 0.35 /spl mu/m. In consideration of the experimental results, we could confirm that a DWDD disk with blue LD readout and recording could be available with an areal density of 15 Gbit/inch/sup 2/ with a jitter criterion of 15%.