Patent ID: 9310604
Filing Date: 2016-04-12
CPC Classification: G02B,G03F

Claim Text:
1. An illumination optical apparatus which illuminates an illumination target surface through use of a beam, comprising: a light splitting device which splits the beam into a plurality of beams with respective polarization states different from each other; a spatial light modulation device which is arranged on at least one of a first optical path in which a first beam out of the plurality of beams travels and a second optical path in which a second beam out of the plurality of beams travels, and which is configured to adjust a phase difference between the first beam and the second beam by changing an optical path length of the first optical path and an optical length of the second optical path; and an optical system which illuminates the illumination target surface with light wherein the first beam and the second beam are overlapped at least in part, wherein polarization states of the first beam and the second beam overlapped at least in part are adjusted by adjusting the phase difference between the first beam and the second beam.