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.

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Domain wall mobility in magneto-optic (MO) media is important in determining the thermomagnetic recording and erase process. However, measurement of domain wall mobility has been difficult due to the large coercivity of MO media near room temperature and the weak MO signal at high temperature. With an improved high speed polar Kerr MO camera system, the dynamics of domain wall motion can now be imaged and measured at temperatures near T curie. The domain wall mobility in GdTbFe samples was measured with the bubble collapse method. The experimental results show that the domain wall motion velocity is a linear function of applied bias field and the domain wall mobility is about 0.3 cm/sOe. Samples with different preparation methods are compared and the experiment shows that whereas the dynamic coercivity varies with the preparation method, the mobility is an intrinsic property and dependent primarily upon sample composition.

Reading dynamics in front aperture detection (FAD) and center aperture detection (CAD) magnetic super resolution (MSR) media is studied using a high speed Kerr microscope system with 10-ns resolution, The effects of disk structure and reading conditions on the reading dynamics are investigated, Readout of 0.2 micron domains is successfully demonstrated using 488 nm wavelength light on CAD MSR media,

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