OPTICAL SYSTEM, IN PARTICULAR IN A MICROLITHOGRAPHIC PROJECTION EXPOSURE APPARATUS

摘要

The invention concerns an optical system, in particular in a microlithographic projection exposure apparatus, comprising a first optical component (110, 210, 910), a second optical component (120, 220, 920), and a measurement arrangement for determining the relative position of the first optical component and the second optical component in six degrees of freedom, wherein the measurement arrangement is adapted to determine the relative position of the first optical component and the second optical component over six different length measurement sections (131-136; 231-236), wherein said length measurement sections (131 -136; 231 -236) extend directly between the first optical component (110, 210, 910) and the second optical component (120, 220, 920).