Patent ID: 8705170
Filing Date: 2014-04-22
Classification: G02B,G03F

Abstract:
1. An imaging optical system for imaging a reticle to a pair of imaging locations, comprising imaging optics configured to simultaneously image the reticle to the pair of imaging locations, wherein the imaging optics forms an image of an object arranged on a first surface of the reticle on a second surface at one of the pair of imaging locations, by catadioptric imaging optics that comprises a first optical system arranged between the first surface and the second surface; a second optical system, arranged in an optical path between the first optical system and the second surface, having a concave mirror; and a third optical system arranged in an optical path between the second optical system and the second surface, wherein a first intermediate image is formed in an optical path between the first optical system and the second optical system, and a second intermediate image of a primary image of the first intermediate image is formed in an optical path between the second optical system and the third optical system, wherein the second optical system further comprising positive lenses, and wherein the positive lenses are arranged in an optical path between the first intermediate image and the concave mirror, and between the concave mirror and the second intermediate image.