Patent ID: 8462434

Claim:
A polarizing beam splitter comprising: a periodic structure including a plurality of structured portions periodically disposed in a first direction at intervals equal to or shorter than a used wavelength, wherein the periodic structure satisfies a condition that polarized light, of an incident light flux, that vibrates in one direction is totally reflected; an incident medium disposed on an incident side of the periodic structure, and an optical interference layer including at least one thin uniform film layer disposed between the periodic structure and the incident medium, the optical interference layer having a thickness equal to or greater than 30 nm and equal to or smaller than the used wavelength, wherein the polarized light vibrating in the one direction is incident on the periodic structure at an angle greater than a critical angle, wherein a polarized light vibrating in another direction perpendicular to the one direction among the incident light flux is incident on the periodic structure at an angle smaller than a critical angle, and wherein refractive indices of the thin uniform film layer are the same at least in the one and another directions.