Probable capacity of 3.5-inch magneto-optical disk using trilayer double-mask magnetically induced super-resolution media

This paper discusses the probable capacity of 3.5-in magneto-optical (MO) disks using trilayer double-mask magnetically induced super resolution (MSR) media and a conventional optical system. We measured the bit error rate of the double-mask MSR media on a land/groove substrate with a track pitch of 0.6 μm. We obtained bit error rates as low as 1e-7 for a minimum bit length of 0.24 μm. The recording power margin was ±11.3% and the tilt margin was ±0.7°. These results indicate that a capacity of over 2.4 GB is possible for a 3.5-in MO disk using an optical head with a 685-nm laser diode having a lens numerical aperture of 0.55. The capacity corresponds to an areal density of 4.48 Gbit/in²