Two-inch-Diameter Magneto-optical Disk System with 3 GB Capacity and 24 Mbps Data Transfer Rate Using a Red Laser

Abstract

Abstract-High-density recording four times that of a current DVD-RAM has been achieved by applying Domain Wall Displacement Detection (DWDD) technology using a conventional optical head which has the same wavelength of 660 nm and NA of 0.6 as the DVD head. It has been confirmed by using a sampled servo and PRML that a recording density of 15 Gbit/inch² with a track pitch of 540nm and bit length of 80 nm has sufficient system margin. This means that a capacity of 3 GB on a two-inch-diameter disk is now available for portable use. If applied to a digitalvideo camera, one hour of MPEG2 video contents can be recorded at a transfer rate of 6 Mbps.