Magnetic expansion read-out of MSR disk with double in-plane magnetic layers

Magnetically induced super resolution (MSR) is a useful technique for high density magneto-optical storage. The magnetic domain expansion disk with double in-plane layers was prepared and its magnetic domain expansion read-out characteristics were measured. The film mainly consists of GdFeCo read-out layer, GdFeCo intermediate layer and TbFeCo memory layer. Given a difference in content of the GdFeCo readout and intermediate layers, it is clearly observed that there exists a threshold read-out laser power. When 0.6 μm continuous domains were recorded on the magnetic expansion disk, the read-out signal level became about 2 times higher than that of a conventional CAD (Center Aperture Detection) disk without an external magnetic field