| 摘要 |
PROBLEM TO BE SOLVED: To reduce cross talk from adjacent tracks by separating reflected light from a record medium to three or above of luminous flux and making the phase compensation amount of the luminous flux when its polarization state is detected so that an absolute value of a difference between the phase compensation amounts required for reproducing signals from a land and a groove becomes within the specified range. SOLUTION: The luminous flux emitted from a semiconductor laser 1, made incident on a polarizing beam splitter 3 to be transmitted is converged to a diffraction limit by an objective lens 4 to be emitted to the land and groove on a recording surface of a magneto-optical disk 5. Reflected luminous flux is led to the polarizing beam splitter 3, and the reflected luminous flux is separated to 0-order light and ±1st-order light by a diffraction grating 6. Respective separated luminous flux are separated to P/S polarization components by a wavelength plate 7 and a Wollaston prism 8, and are photoelectric converted/differential amplified respectively by a photodetector 10, and the reflected luminous flux from the land is separated from the reflected luminous flux from the groove. The absolute value of the difference between the phase compensation amounts required for reproducing the signals from the land and groove is made 60 deg. to 180 deg.. |
