The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 2015
Filed:
Sep. 13, 2012
Danny Chan, Berlin, DE;
Hans-juergen Mann, Oberkochen, DE;
Sascha Migura, Aalen-Unterrombach, DE;
Carl Zeiss SMT GmbH, Oberkochen, DE;
Abstract
An optical system is disclosed that includes a plurality of elements arranged to image radiation at a wavelength λ from an object field in an object surface to an image field in an image surface. The elements include mirror elements have a reflective surface formed by a reflective coating positioned at a path of radiation. At least one of the mirror elements has a rotationally asymmetrical reflective surface deviating from a best-fit rotationally symmetric reflective surface by about λ or more at one or more locations. The elements include an apodization correction element effective to correct a spatial intensity distribution in an exit pupil of the optical system relative to the optical system without the apodization correcting element. The apodization correction element can be effective to increase symmetry of the spatial intensity distribution in the exit pupil relative to the optical system without the apodization correcting element.