Patent ID: 7301700

Claim:
A polarization beam splitter having: a polarized beam splitting layer having a structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, each of the gratings having a refractive index; and two optical members sandwiching therebetween the polarized beam splitting layer, each of the members having a refractive index of which refractive indices are equal to each other, when the refractive indices of the optical members is defined as nP, and the refractive index of the gratings is defined as nG, and a value obtained by dividing a width of the gratings by a disposing period is defined as f, and an incident angle of light incident into the polarization beam splitter is defined as θ, the following conditional expression is satisfied sin ⁢ ⁢ θ ⁢ > □ n p ⁢ f n G 2 + 1 - f , wherein the light of the polarized component parallel to said second direction is reflected by the use of total reflection.