Characteristics of new MAMMOS (Magnetic AMplifying Magneto-Optical System) were evaluated. This method needs only a dc magnetic field for expanding the magnetic domains. We obtained 43 dB of CNR for 0.25 μm packed domains by applying 10 kA/m of dc magnetic field. Compared with the conventional CAD (Center Aperture Detection) disk, the CNR for domains smaller than 0.4 μm was greatly improved.
