| 摘要 |
Illumination optical unit for illuminating an object field in a projection exposure apparatus, comprising a first facet mirror with a structure, which has a spatial frequency of at least 0.2 mm−1 in at least one direction, and a second facet mirror, comprising a multiplicity of facets, wherein the facets are respectively provided with a mechanism for damping spatial frequencies of the structure of the first facet mirror. |
