| 摘要 |
PURPOSE:To equalize a reproducing signal in amplitude and polarity optically and reduce the load on and scale of a signal processing circuit by optimizing the polarization plane passing axis angle and rotating direction of an analyzer when information is reproduced from a photomagnetic recording medium which magnetism information and phase information are recorded together. CONSTITUTION:Information is reproduced by utilizing magnetooptic effect represented by Kerr effect. The Kerr effect inverts the polarization direction of incident light according to the magnetism direction of a vertically magnetized film is upward or downward. Reflected light from a disk 1 having the plane of polarization rotated is passed through an objective lens 6 and separated by a polarizing prism 5 and then guided to the analyzer 9, which is an optical element passing only a specific polarized component. Therefore, when light having the plane of polarization rotated by the Kerr effect according to whether there is a magnetic domain or not is incident on the analyzer 9, it is converted into variation in the quantity of light, which is converted by a photodetector 10 into an electric signal and amplified by an amplifier 11 to a desired level. |
