| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head and an optical disk device which are made sufficiently practical by accurately detecting the extent of relative tilt of an optical disk to an object lens in the optical head at the time of recording and reproducing of the optical disk and correcting a coma aberration in accordance with the detection result. SOLUTION: The optical head is provided with a diffraction grating 15 which diffracts a light beam emitted from a laser light source 12 to a main beam and two side beams to lead them to an object lens 20, a polarizing diffraction grating 18 which diffracts respective light beams, which are reflected by an optical disk 11 and reversely pass the object lens 20 and are made incident, to 0th-order diffracted light and ±1st diffracted light, and a photodetector 24 which converts each light beam generated by the polarizing diffraction grating 18 to an electric signal. |
