| 摘要 |
PURPOSE:To increase the response speed limit, by providing a soft magnetic film surface vertical easy magnetized film in such way that the magnetic anisotropy of the said film become parallel to the shifting direction of a magnetic medium. CONSTITUTION:A magnetic garnet film 2b composed of Eu2.09La0.75Ca0.16Ge0.16 Al0.55Ga0.12Fe4.17O12 is provided on the back of a GdGa garnet substrate 2a, and then a diffusion preventing film of SiO2, an Al vapor-deposited film 2e and an SiO2 protective film are provided. A resistive coating 20 is applied on the upper surface of the substrate 2a. A soft magnetic garnet film 2 is provided so that the direction of its magnetic anisotropy is parallel to the shifting direction (arrow mark) of a magnetic tape 1. For instance, the beam given from an He-Ne laser is condensed to the film 2 via a polarizer 4 and a beam spliter 6. For the reflected light that receives the Faraday optical rotation corresponding to the magnetization of the film 2, the light modulated signal enters a photoelectric transducer 8 via photodetector 7. Thus an electric signal 9 corresponding such light modulated signal is delivered. As a result, the response speed limit can be increased. |
