| 摘要 |
PURPOSE:To prevent the deterioration of a reproduced signal due to birefringence in a substrate by using a photodetector having a cruciform light receiving part in a magneto-optical signal detecting part. CONSTITUTION:A magneto-optical head consists of a laser light source 20, a collimator lens 21, beam splitters 22 and 23, a laser light condensing part 24, a servo signal detecting part 25, and a magneto-optical signal detecting part 26. The light receiving face of a photodetector, namely, a photodiode used in the magneto-optical signal detecting part 26 is formed to a cross. The shape of the light receiving face is easily formed by the known photodetector generating method, and a mask for intercepting the light may be stuck to the round or square light receiving face. Directions of polarization of the laser light made incident on the photodetector are allowed to coincide with directions of the cross of the cruciform light receiving face of the photodetector, thereby eliminating the polarization state deterioration part due to birefringence included in the reflected light from a medium. |
