| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head device capable of easily arranging a diffraction grating in an optical path under an optimum condition. SOLUTION: In an optical head device, a first positioning index 121 attached to a first diffraction grating 12 composed of a modulated diffraction grating whose grating pattern has unequal intervals is aligned with a second positioning index 74 attached to a diffraction grating mounting area 73 constituted on a unit case 7, the mounting position of the first diffraction grating 12 is determined and the outer peripheral end face of the diffraction grating 12 is not used for the aligning reference. |
