Sn-Sb-Se/Sb-Bi Bilayer Phase-Change Media for High-Density Write-Once Optical Recording

Abstract

We have developed Sn-Sb-Se/Sb-Bi bi-layer phase-change media for high-density write-once optical disks. Crystallized marks as small as 0.5 µ m are stably recorded without initialization. These phase-change media, compared to ablative type write-once media, have high carrier-to-noise ratio, low jitter, and long life. Mark-edge recording with multi-pulse laser irradiation on the media provides a linear bit density of 0.48 µ m/ bit and track pitch of 1.2 µ m using a 690-nm-wavelength laser diode and 0.55 numerical aperture (NA) objective lens. This corresponds to 1.1 Gbit/in.2, or 14 GB formatted data capacity per both sides for a 12-inch-diameter disk with a zoned constant angular velocity (ZCAV) format.