Ryuichi Furukawa

Semi transparent Recording Stack with Fast-Crystallization Phase-Change Material for Dual-Layer Optical Disk

We report the experimental results of a semi transparent recording stack with a fast-crystallization (FC) phase-change material for a dual-layer optical disk, using a pickup with a blue laser diode at 405 nm and a lens numerical aperture (NA) of 0.85 to achieve the highest capacity. The transmittance of 47% and the clock-to-data jitter of approximately 9% were obtained from the semi transparent recording stack. We confirmed that the FC phase-change material could be applied to a high-capacity dual-layer recording system.

High-speed blue-laser recording on the double-decker phase change disk with high-reliability

In this paper, we report the feasibility of 100 Mbps data transfer-rate with high reliability and wide-power margin that media can apply to double-deck high density recording of 42 GB capacity corresponding to an optical recording disk system (K. Schep et al, ISOM Tech. Dig., p. 210, 2000) using a blue laser diode at 405 nm, and NA (numerical aperture) of 0.85.

100-Mbps high-speed phase-change recording with blue laser

We have studied a phase-change recording with a blue laser diode wavelength (405nm), an objective lens (NA 0.85) and Ag-In-Sb-Te system phase change material. We report land and groove recording on a 0.1mm thin cover disk structure, and 120mm-diameter polycarbonate substrate. Finally we confirmed the possibility of high data transfer-rate 100Mbps and high-density 20.9GB corresponding to those of a new optical recording system (DVR) (1) at the condition of recording velocity 17m/s, linear density of 0.130 micrometers /bit and 0.35 micrometers track-pitch.