Readout scheme by pulsed irradiation center aperture detection on magnetically induced super resolution magnetooptical disks

Abstract

Magnetically induced super resolution (MSR) is used to read ''below-diffraction-limit'' recording marks on magneto-optical (MO) media. A nanosecond-order laser pulse irradiated onto MO media can create a quasicircular temperature profile, thereby yielding a quasi-circular sub-mu m aperture to effectively derive a readout signal from sub-mu m marks recorded on the disks. In this study, the pulsed irradiation and conventional DC readout methods are applied to a MO disk with a center aperture detection (CAD) structure to quantitatively evaluate their readout performance. The size and shape of the effective aperture, jitters due to readout parameters; and aperture wall width generated are studied. The feasibility of the pulsed irradiation readout is then assessed.