DIFFRACTION ELEMENT, OPTICAL PICKUP AND OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a diffraction element capable of suppressing absorption of moisture into material constituting a diffraction grating 2 to such a level as to exert no influence on characteristics of diffraction even when being exposed to environments of high temperature and high humidity.

SOLUTION: The diffraction element 1 comprising a transparent substrate 3 and the diffraction grating 2 formed on the surface of the transparent substrate 3 is provided with: the transparent substrate 3 in which prescribed transparent protruded members 4 constituting the diffraction grating 2 are disposed on the surface thereof; a transparent protective plate 6; a transparent packed member 5 which is packed between unevenness constituted by the transparent substrate 3 and the protruded member 4, and the transparent protective plate 6; and a sealing member 8 which binds the transparent substrate 3 to the transparent protective plate 6 and annularly surrounds the outside of the packed member 5.

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