Patent ID: 7084977

Claim:
An exposure apparatus including: a light source generating light flux; an illumination optical system introducing said light flux to a photomask; and a projection optical system projecting an image of a mask pattern onto an object to be exposed; said exposure apparatus further comprising: a first polarization conversion system serially converting said light flux into any of a plurality of polarized light beams perpendicular to each other on Poincare sphere and outputting said polarized light beam; a light intensity detection section disposed near an imaging position at which said projection optical system forms the image of said mask pattern to detect a light intensity of a converted polarized light beam obtained from said polarized light beam passing through said illumination optical system, said photomask, and said projection optical system; a second polarization conversion system including a linear polarizer and a linear phase retarder, which is inserted in an optical path of said converted polarized light beam; a parameter calculation section switching said linear polarizer between azimuths and switching said linear phase retarder between being inserted into and removed from the optical path or between azimuths, to obtain a plurality of data on said light intensity detected by said light intensity detection section and calculate Stokes parameters of said converted polarized light beam based on the plurality of data on the light intensity obtained; and a Mueller Matrix calculation section for calculating Mueller matrix of an optical system existing before the position at which said second polarization conversion system is inserted, based on the calculated Stokes parameters of said converted polarized light beam and the Stokes parameters of said polarized light beam output from said first polarization conversion system.