Reading Dynamics in Central Aperture Detection(cad) Magnetic Super Resolution (Msr) Media

Abstract

We present, for the first time, the direct observation of the dynamic reading process in central aperture detection (CAD) magnetic super resolution (MSR) media. The stroboscopic images taken by a IOns exposure time high speed Kerr microscope system on an airbearing spin stand are compared with the corresponding CNR measurements on a MO spin stand. Dynamics of the reading process in samples with and without an intermediate layer and at different reading conditions are studied. Our analysis indicates that the intermediate layer sharpens the threshold for copying the data into the readout layer. We find that optimizing the reading power in CAD MSR readout is critical in order to a'chieve fast copy speed and provide clear and complete copying. The optimal reading power increases with the increase of the linear velocity of the disk, as expected. Higher disk velocity results in a smaller thermal aperture, which is shifted further from the center of the optical aperture, resulting in a decrease in CNR.

Reading dynamics in Front Aperture Detection (FAD) MSR media

“…However, the commonly regarded drawback of FAD MSR media lies in the fact that it has relatively higher crosstalk between tracks due to the wider effective aperture. To understand the dynamics of the reading process in FAD MSR media, a high speed Kerr microscope system built on an air bearing spin stand [2] was used to directly observe and record the dynamics of the thermal mask and the effective aperture in FAD disks during readout.…”