| 摘要 |
PURPOSE:To increase magnetooptical effect and to form a guide track for servocontrol, by providing a reflecting layer and making step difference to a substrate. CONSTITUTION:In a substrate 1, a beltlike groove 7 is formed, and an amorphous ferromagnetic material is provided on it to form a vertical magnetization film. Further, a transparent dielectric film 3 is formed on said film, and a reflecting film 4 is formed. The reflecting film 4 is bonded to a base substrate 6 with an adhesive layer 5. Recording, reproduction and erasure are performed through the substrate 1. As a guide track, the groove part 7 and a bank part 8 are usable. A magnetic film 2 is thick enough, and light for reproduction incident to a magnetic material layer, thereby increase several times in turning angle of the plane of polarization in comparison with only Kerr effect by reflection from the surface of the magnetic material, and by the combination of the Kerr effect and Faraday effect provided when the light passes through the magnetic material film is reflected again by the reflecting layer 4, and then passes through the magnetic material film again. |
