| 摘要 |
PURPOSE:To simplify and miniaturize the constitution and to improve the S/N and also to increase the recording density by specifying the grating direction of diffraction gratings of two kinds of recording signal detection and tracking signal detection respectively provided on the same substrate for receiving and diffracting the reflected light from a recording surface. CONSTITUTION:The reflected light from a magneto-optical recording medium due to the irradiation of light of a light source is polarized by a magneto-optical effect according to the recording information to become recording signal detecting light through waveguide paths 8a and 8b corresponding to the two kinds of diffraction gratings 6a and 6b having their different grating directions provided on the substrate, so as to be incident upon photo detectors 11a to 11d. Other diffraction gratings having their diffracting directions different from the gratings 6a and 6b with photo detectors 7a with 10a and 7b with 10b are also provided on this substrate to receive tracking signal detecting light. By this constitution of using three different kinds of diffraction gratings in diffracting direction, the diffracting direction can easily be set up, and the intensity distribution of the emitting light from the light source can be met in the tracking direction in the small size and simple constitution, thus promoting the S/N and the recording density. |
