Abstract: A method of forming a radiation filter for a lithographic system, the method including forming at least one structure in or on a filter body, wherein the at least one structure provides a filtering effect and least one of a), b), c) or d): a) the at least one structure includes a plurality of transmissive, reflective, absorbing or fluorescent structures, and the method includes providing a desired distribution of the structures to provide a desired filtering effect; b) forming the at least one structure includes forming at least one transmissive, absorbing, reflective or fluorescent layer that has a variable thickness; c) forming the at least one structure includes altering at least one optical property to provide a variation of the optical property with position; d) the at least one structure includes a fluorescent layer that provides variation of at least one fluorescence property with position and/or angle of incidence.

Abstract: In a Faraday microscope for examining specimens with stray magnetic fields in a reflected light beam path with a magnetic indicator film arranged in front of the specimen, the influence of the specimen on the indicator film is evaluated with the indicator film arranged as the termination of the microscope objective, the indicator film advantageously being arranged on an optically transparent substrate. The indicator film and substrate are taken into account in the optical calculation of the microscope objective.