Patent ID: 7612940

Claim:
A diffractive optical element in which mutually different materials make contact with one another via the same diffraction grating groove, wherein one of the mutually different materials is a first ultraviolet curing resin and the other of the mutually different materials is a second ultraviolet curing resin that is different from the first ultraviolet curing resin, wherein, when the refractive index at line d of the first ultraviolet curing resin is nd 1 , the dispersion value of the first ultraviolet curing resin is vd 1 , the refractive index at line d of the second ultraviolet curing resin is nd 2 , and the dispersion value of the second ultraviolet curing resin is vd 2 , the condition of expression 0.0015778≦( nd 1−nd2)/( vd 1− vd 2)≦0.03 is satisfied.