| abstract |
A diffractive optical element ( 10 ) includes a substrate ( 11 ), a protective film ( 13 a , 13 b ), and a diffraction grating ( 12 a , 12 b ) disposed between the substrate ( 11 ) and the protective film ( 13 a , 13 b ), wherein the diffraction grating ( 12 a , 12 b ) is formed of a composite material containing a resin and inorganic particles, a volume ratio of the inorganic particles with respect to the composite material is equal to or smaller than 50% by volume, and the diffraction grating ( 12 a , 12 b ) has a thickness of equal to or smaller than 20 μm. Since the diffractive optical element ( 10 ) uses the composite material containing the resin and the inorganic particles as a material for the diffraction grating ( 12 a , 12 b ), which is relatively difficult to process, the moldability improves compared with the conventional case of using glass, etc. |