High carrier-to-noise ratio achieved on magneto-optic recording disks using a plurality of magneto-optic recording layers

Abstract

Very high carrier-to-noise ratios of 67 dB (30 kHz bandwidth) were achieved on magneto-optic recording disks that utilize two thin magneto-optic layers. This improvement came primarily from the reduction in the disk writing noise. We explain this noise reduction through the statistical averaging of the written magnetic transition positions in these two active layers. In principle the disk writing noise can be further reduced when more active layers are utilized in the disk structure.