| 摘要 |
PURPOSE:To attain the reading of high density recording information on a recording medium with high sensitivity and high S/N by using a vertical film as a reading medium and utilizing the magnetooptic effect. CONSTITUTION:The parallel light from a light source 4 reaches the state of linear polarized light 18 through a polarizer 5 and is converged by an objective lens 6. The converged light is reflected by a reflecting mirror film 22 coated on the lower face in case of a vertical film 21 such as a magnetic garnet film through which the light is transmitted, and the polarized plane of light is rotated by the magnetooptic effect depending on the magnetized state of the film 21. The optical path direction of the rotated light is changed by a translucent mirror 10 and the light is incident to an analyzer 8 via a lens 7. The rotating state of the polarized face through the analyzer 8 is converted into a signal of intensified/unintensified light, converted into an electric signal at a photodetector 9 and then extracted. |
