| 摘要 |
According to one embodiment, an illumination optical system configured to illuminate an illumination target surface on the basis of light from a light source comprises a distribution forming optical system and a correction unit. The distribution forming optical system forms a pupil intensity distribution on an illumination pupil of the illumination optical system. The correction unit changes an emission direction of a beam according to an incidence position of the beam, in order to correct the pupil intensity distribution. The correction unit is arranged at or near a position of the illumination pupil, or, arranged at or near a position optically conjugate with the illumination pupil. |
