| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffraction grating which has high thermal resistance against radiation of a light with high energy density.SOLUTION: The diffraction grating 10 is composed of materials other than oxide silicon which have a larger band-gap than the band-gap of oxide silicon, and has a grating section 11 with periodic structures 111 formed at a prescribed interval on its surface. The diffraction grating desirably has dielectric lamination sections 12, in which two types of dielectric substances having high laser resistance and different refraction factors are alternatively laminated, disposed on both the light irradiation surface side and the opposite surface side of the grating section 11. |
