| 摘要 |
PROBLEM TO BE SOLVED: To provide a reflection type diffraction grating representing high diffraction efficiency over a wide wavelength range.SOLUTION: The lattice plane of a reflection type diffraction grating 30 includes a first reflection region 1 composed of a first substance and a second reflection region 2 composed of a second substance. Since a first reflection region and a second reflection region are included in the radiation regions 3 of incident light, diffraction light becomes mixed light of reflected light by each of the first reflection region and the second reflection region, and the first reflection region 1 and the second reflection region 2 complement each other regarding reflectance. As a result, the reflection type diffraction grating 30 can represent high diffraction efficiency over a wide wavelength range. |
