| 摘要 |
PROBLEM TO BE SOLVED: To prevent diffraction efficiency from being deteriorated due to refractive index distribution, in a diffractive optical element which comprises a resin layer formed of a photo-curable resin material. SOLUTION: The diffractive optical element has a diffraction grating 10 formed of two resin layers 3, 4 layered between glass substrates 1 and 2. The resin layer 4 is composed of a fluororesin in which metal oxide fine particles are dispersed. Since the refractive index distribution easily occurs in the material during curing by the application of ultraviolet light, by applying ultraviolet light perpendicularly to the inclined surfaces 111 of the diffraction grating shape 10, refractive index distribution is formed in the thickness direction perpendicular to the inclined surfaces 111. COPYRIGHT: (C)2010,JPO&INPIT |
