Patent ID: 8351021

Claim:
An optical system comprising a birefringent optical rotator which is made of an optical material with linear birefringence and optical rotatory power, an optic axis of the birefringent optical rotator is arranged substantially in parallel with an optical axis of the optical system, wherein a beam bundle in a substantially circular polarization state is incident to the birefringent optical rotator, the birefringent optical rotator is located at a position where a beam bundle of substantially spherical waves is incident thereto, and the birefringent optical rotator includes a required thickness for converting a beam bundle in a peripheral region of the incident beam bundle into a beam bundle in a substantially linear polarization state of substantially circumferential vibration in a lens aperture, a first optically transparent member made of an optical material with clockwise optical rotatory power, and a second optically transparent member made of an optical material with counterclockwise optical rotatory power.