Patent ID: 8085382

Claim:
A system, comprising: an optical system having an optical path, an object plane and a pupil plane, the optical system being configured so that, during use when light passes through the optical system along the optical path, the optical system illuminates a field of the object plane with the light, the optical system comprising: a first optical module configured so that during use the first optical module sets a first illumination setting in the pupil plane of the optical system; a second optical module configured so that during use the second optical module sets a second illumination setting in the pupil plane of the optical system; at least one decoupling element in the optical path upstream of the first and second optical modules, and configured so that during use the decoupling element provides light to: only the first optical module; or only the second optical module; or both the first and second optical modules; and at least one coupling element in the optical path downstream from the first and second optical modules, wherein: the at least one coupling element is configured so that, during use of the system when the at least one decoupling element provides light to both the first and second optical modules, the at least one coupling element integrates the light which has passed through the first and second optical modules into a common light ray path which is provided to the illumination field, wherein the optical system is a microlithographic projection exposure apparatus illumination optical system.