| 摘要 |
PROBLEM TO BE SOLVED: To provide a diffractive optical element suppressing location dependency of diffraction efficiency in a grating surface based on variation in thickness when assembling a base layer in a diffraction grating, and to provide a method for manufacturing the same, and an optical system using the diffractive optical element.SOLUTION: The diffractive optical element includes a diffraction grating part in which a first diffraction grating 1 and a second diffraction grating 2 that are formed from mutually different materials, are superposed, with each grating surface coming into contact with each other. The first diffraction grating 1 and the second diffraction grating 2 have a first base layer and a second base layer under each grating surface respectively. A difference &Dgr;E of Young's moduli of the mutually different materials satisfy the following conditional expression (0≤|&Dgr;E|<3.0 GPa). |
