Patent ID: 9563130
Date: 2017-02-07
CPC Classifications: G02B,G03F

Claim:
1. An illumination optical system for illuminating an illumination target surface with light from a light source, comprising: a polarization converting member which is arranged in an optical path of the illumination optical system and which converts a polarization state of incident light so as to form a pupil intensity distribution in a predetermined polarization state on an illumination pupil of the illumination optical system; a first path bending mirror having a planar reflecting surface; and a wave plate which is arranged in the optical path between the polarization converting member and the first path bending mirror and an optic axis of which is set in a direction along a first plane including an optical axis of an optical system arranged on the light source side of the first path bending mirror and an optical axis of an optical system arranged on the illumination target surface side of the first path bending mirror, or in a direction perpendicular to said direction along the first plane.