| 摘要 |
PURPOSE:To enable recording of bit information even if a semiconductor laser having a long wavelength is used by impressing a bias magnetic field in such a way that magnetization attains the state facing one perpendicular direction with respect to the film plane and making pulses of light incident on the single magnetic domain thereof thereby recording the bit information. CONSTITUTION:A film 2 having the axis of easy magnetization prependicularly to the plane of the soft magnetic film to be subjected to recording by magnetic bubbles is deposited and formed on a crystal base plate 1 and a metallic film 3 is laminated thereon so as to be directly adjacent thereto to constitute a recording medium 4. The metal for the film 3 refers to transition metals of the I b, IIb group, IIIa, IVa, Va, VIa, VIIa group and VIII group in periodic table and are enumerated by Al, Cr or the alloys thereof as a representative example. A bias magnetic field is impressed to the film 2 in such a way that the single magnetic domain is formed over the front surface thereof and that the magnetization attains the state facing one direction perpendicular to the film plane. Light pulses having a prescribed wavelength are made incident on the single magnetic domain thereof to form the cylindrical magnetic domain magnetized in the direction opposite from the magnetization direction of the bias magnetic field impressed to the film, by which the bit information is recorded.
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