Patent ID: 9164209
Filing Date: 2015-10-20
Classification: G02B,G03F

Abstract:
1. An illumination optical apparatus which illuminates an object with a beam, the illumination optical apparatus comprising: an optical member made of an optical material with optical rotatory power, which rotates a polarization direction of a linear polarization incident on the optical member, the optical member being arranged in an optical path of the beam so that an optic axis of the optical material of the optical member is substantially parallel to an optical axis of the illumination optical apparatus at a location where the optical material is arranged; an optical integrator arranged in the optical path of the beam on an exit side of the optical member; and an optical system arranged in the optical path between the optical member and the optical integrator, which locates the optical member and an entrance surface of the optical integrator substantially in the relation of Fourier transform so as to form an illumination area on a pupil plane of the illumination optical apparatus, the pupil plane substantially being located at a rear focal plane of the optical integrator, wherein the optical member includes a first portion having a first length and a second portion having a second length different from the first length, the first and second lengths are a length between an entrance surface and an exit surface of the optical material of the optical member in a direction of the optical axis, the illumination area on the pupil plane is formed so that a first beam passing through the first portion of the optical member passes through a first region of the illumination area and a second beam passing through the second portion of the optical member passes through a second region of the illumination area, the second region being different from the first region, the first and second beams being part of the beam, and the beam of which a polarization direction is rotated by the optical member on the basis of the optical rotatory power is irradiated onto the object through the pupil plane.