| 摘要 |
An object is to reduce polarization dependency for obliquely incident light and to eliminate problems such as ghost images generated by reflection on two surfaces. An optical multilayer band pass filter includes a substrate transparent to subject light, an LWPF part provided only on one side of the substrate, which forms a rise portion and a reflection band on a shorter wavelength side in band pass characteristics, an SWPF part, which forms a fall portion and a reflection band on a longer wavelength side in the band pass characteristics, and a polarization dependency improvement part, which controls split-up between a P-wave and a S-wave occurring in the rise portion and the fall portion formed respectively by the LWPF part and the SWPF part when the subject light is incident obliquely. The LWPF part, the SWPF part, and the polarization dependency improvement part have a structure in which a plurality of higher refractive index layers made of a first dielectric material and a plurality of lower refractive index layers made of a second dielectric material having a refractive index lower than the first dielectric material are deposited alternately. |
