低再生磁界D-RAD

抄録

Recently many types of magnetically induced super-resolution (MSR) have been proposed for high-density recording on magneto-optical (MO) disks. Among them, double-mask rear-aperture detection (D-RAD) is the most promising, because of its high resolution and its crosstalk advantage. However, D-RAD requires a high external magnetic field for MSR readout. We investigated MSR by D-RAD in order to reduce the readout magnetic field. By optimizing the structure of MSR by D-RAD, we achieved a small magnetic field of −100 Oe for readout. In recording on a D-RAD MO disk with land/groove recording, a C/N of more than 45 dB for a mark length of 0.27 μm and a cross-talk level of less than −40 dB at a track pitch of 0.7 μm were achieved. In addition, a combination of light intensity modulation direct overwrite (LIMDOW) with D-RAD was achieved by adding on MSR switching layer to D-RAD.