| 摘要 |
PURPOSE:To detect accurately the recording state, by forming the 1st magnetic layer with a magnetic body having high permeability and a large Kerr effect, and then the 2nd magnetic layer having a magnetization facilitating axis in the direction vertical to the film surface on a transparent substrate in order, then utilizing the vertical magnetic Kerr effect in the reproduction mode. CONSTITUTION:The light given from a light source 13 is polarized by a polarizer 14 and condensed to the lower surface of a magnetic layer 12 by a condenser lens 15 and through a transparent substrate 10. For the reflected light, the polarized face turns in accordance with the direction of the magnetization 20 by a vertical magnetic Kerr effect. This reflected light is condensed through a condenser lens 16, and the polarized face is turned by a photodetector 17 by a Kerr rotational angle corresponding to either magnetization within a magnetic layer having high permeability. Thus the optical intensity is obtained in response to the direction of the magnetization 20. This optical intensity is converted into an electric signal by an optical detector. As a result, a signal output corresponding to the magnetization 19 within a vertical magnetized film 11 is obtained. In such way, the reproduction of an extremely small track width is possible by utilizing the vertical magnetic Kerr effect instead of the reproduction carried out by a magnetic head. |
