Patent ID: 7379242

Claim:
A polarization beam splitter comprising: a multilayer film formed by laminating a first layer having a refractive index in a first range, a second layer having a refractive index in a second range which does not overlap the first range, and a third layer having a refractive index in a third range which does not overlap the first or second range in the order of the first layer, the second layer, the first layer, and the third layer, wherein the transmittance of s-polarized light is 60% or more higher than the transmittance of p-polarized light in a first wavelength region, the transmittance of p-polarized light is 60% or more higher than the transmittance of s-polarized light in a second wavelength region different from the first wavelength region, and each of the first wavelength region and the second wavelength region has a bandwidth equal to or larger than 30 nm.