| 摘要 |
A projection exposure apparatus (10) for microlithography comprises a plurality of optical components (M1-M6) forming an exposure beam path, and comprises a distance measurement system (30, 130, 230) for measuring a distance between at least one of the optical components (M1-M6) and a reference element (40, 140, 240). The distance measurement system comprises a frequency comb generator (32, 132, 232), which is configured for generating electromagnetic radiation (36, 236) with a comb-shaped frequency spectrum. |
