OPTICAL DEVICE CONTAINING DOUBLE-FACE MULTILAYERED FILM SUBSTRATE, ITS PRODUCTION, SENSOR DEVICE AND DOUBLE-FACE MULTILAYERED FILM SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To obtain desired optical characteristics without deterioration in characteristics of a double-face multilayered film substrate even when the substrate is disposed in any direction by controlling the refractive index of the outermost layer of the double-face multilayered film substrate to be larger than the medium in contact with the both surfaces. SOLUTION: A band pass filter(BPF) 11 of a double-face multilayered film substrate consists of an optically transparent substrate such as a glass substrate 12, and optical multilayered films 13, 14 formed on both surfaces of the substrate. Each optical multilayered film 13, 14 consists of thin films of Al2 O3 , SiO2 and TiO2 in such a manner that the outermost layer is an Al2 O3 film and that SiO2 films and TiO2 films are alternately deposited to form the inner part. Namely, the outermost layer of the BPF11 in contact with different media A (air) and B (resin) consists of Al2 O3 which has a larger refractive index than those of the media A, B. Thereby, changes in the characteristics when the substrate is turned upside down can be decreased.