Patent ID: 7466486

Claim:
A polarization separating element comprising a structural birefringence body having a base body made of a photosensitive material having a periodic refractive index distribution, wherein at least a pair of surfaces is formed in the base body in which one surface is a light incident location and the other surface is a light emitting location, wherein a direction of an interface of the periodic refractive index distribution is neither parallel nor perpendicular with respect to a normal line of an incident surface of the base body, the direction of the interface being inclined at a predetermined angle with respect to the incident surface, and being further inclined at a predetermined angle with respect to a direction of incident light, and wherein the periodic refractive index distribution includes: a first periodic refractive index distribution formed in a first direction with a first periodic interval; and a second periodic refractive index distribution formed in the same base body in a second direction different from the first direction with a second periodic interval.