| 摘要 |
PROBLEM TO BE SOLVED: To provide an illumination optical system capable of achieving uniform integrated illuminance distribution on an illumination target surface by use of a relatively smaller number of light pulses even when a high-coherence light source is used.SOLUTION: The illumination optical system illuminates an illumination target surface with a plurality of number of light pulses from a light source. The illumination optical system includes: a formation optical system for forming a first illuminance distribution 41a in an illumination target surface on an object, in which the intensity of light varies in a predetermined direction by use of first light pulses in the plurality of light pulses, as well as for forming a second illuminance distribution 41b in the illumination target surface, in which the intensity of light varies in a predetermined direction by use of second light pulses in the plurality of light pulses; and a relative position changing part for changing relative positions in the predetermined direction of at least a part of the first illuminance distribution 41a and of at least a part of the second illuminance distribution 41b with respect to the object.SELECTED DRAWING: Figure 7 |
