| 摘要 |
PROBLEM TO BE SOLVED: To provide an absorption type multilayered ND filter excellent in environmental resistance. SOLUTION: The absorption type multilayered ND filter includes absorption type multilayered films constituted by alternately laminating oxide dielectric films and metal films on at least one surface of a substrate composed of a resin film. The metal films are constituted of Pt single units, and the oxide dielectric films are composed of the SiOx(1.5<x<2) formed by controlling an introducing amount of oxygen during deposition by a physical gas phase growth method. The flat nature of the special transmission characteristics defined by dividing the difference between the maximum transmittance and minimum treatment in a visible wavelength region (wavelength 400 to 700 nm) of the absorption type multilayered films by average transmittance is≤10%, and reflectivity in the visible wavelength region of the absorption type multilayered films is≤5%. COPYRIGHT: (C)2009,JPO&INPIT
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