| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical filter showing low reflection and having light-absorbing property, and to provide an optical device using the optical filter and a method for manufacturing the optical filter. <P>SOLUTION: The optical filter includes, on a substrate 13, a refractive index gradient thin film 12 having a refractive index varying stepwise in a thickness direction and an antireflective structure 111 for reducing reflection. The refractive index of the refractive index gradient thin film 12 is varied in a film thickness direction in such a manner that in a part on the substrate 13 side, the refractive index comes close to the refractive index of the substrate 13, while in a part on the antireflection structure 111 side, the refractive index comes close to the refractive index of the antireflection structure 111. The optical filter is used for a photographing optical system. <P>COPYRIGHT: (C)2013,JPO&INPIT |
