Super Resolution in Magneto-Optical Disks

Super-resolution in magnetooptic disks is reviewed. Magnetically induced super-resolution (MSR) has been achieved using exchange-coupled magnetic multilayer films. Two types of detection method, Front Aperture Detection and Rear Aperture Detection, have been developed. The principle of MSR is discussed in this paper based on the exchange coupling between magnetic layers. The cutoff spatial frequency at which a signal approaches zero is more than twice as high for the MSR disk as for a conventional disk. A high C/N of more than 42 dB was obtained in both types of disk for a mark length of 0.3 μm, which is much shorter than the cutoff in conventional detection.