HIGH DENSITY RECORDING WITH A SUPER RESOLUTION MAGNETO-OPTICAL DISK USING MAGNETIC FIELD MODULATION METHOD

摘要

We have improved the recording magnetic field sensitivity of a magnetic super resolution (MSR) disk consisting of double magnetic layers and examined the magnetic field modulation recording properties. An areal density of 2.2 Gbit/in(2) was obtained with a currently available condition. The experimental optical pickup system had a 680 nm wavelength laser diode and an objective lens of a 0.55 numerical aperture. The MSR disk had 0.7 mu m-width lands and grooves. The crosstalk values between the land and its adjacent grooves were less than -28 dB. The areal density in the improved MSR disk was accomplished by recording in both lands and grooves and using mark edge recording with a (1,7) run-length-limited coding. Also, if a signaling technique called 'PRML' is used, an areal density of 3.1 Gbit/in(2) could be realized. [References: 10]