| 摘要 |
A diffractive optical element has higher diffraction efficiency of diffracted light of a designed order in a visible wavelength range. The diffractive optical element includes a diffraction grating part provided on a lens surface of an optical system and constituted by laminating first and second diffraction gratings made of two different materials. Each of the first and second diffraction gratings includes a grating surface and a grating wall surface. The grating surfaces of the first and second diffraction gratings are in contact with each other. The diffraction grating part has the designed order of at least +2nd order and has a grating height of at least 6μm. |
