Patent ID: 6362926
Filing Date: 2002-03-26
Classification: G02B,G03F

Abstract:
A catadioptric optical system that forms a reduced image of a first surface onto a second surface, comprising:a) a first imaging optical system that forms an intermediate image of said first surface; b) a second imaging optical system that forms the reduced image of said intermediate image onto said second surface; and c) wherein said first imaging optical system includes a concave reflecting mirror, and a 1âˆ’2th lens group arranged in the optical paths between said first surface to said concave reflecting mirror and between said concave reflecting mirror to said intermediate image, said second imaging optical system includes a 2âˆ’1th lens group having a positive refractive power, an aperture stop arranged in the optical path between said 2âˆ’1th lens group and said reduced image, and 2âˆ’2th lens group arranged between said aperture stop and said reduced image and having a positive refractive power, at least one positive lens among the positive lenses in said 1âˆ’2th lens group is formed of fluorite, at least one positive lens among the positive lenses in said 2âˆ’1th lens group is formed of fluorite when the pupil plane of said first imaging optical system is positioned between said first surface and said concave reflecting mirror, and at least one positive lens among the positive lenses in said 2âˆ’2th lens group is formed fluorite when the pupil plane of said first imaging optical system is positioned between said concave reflecting mirror and said intermediate image, and excluding said positive lenses formed of fluorite, the lenses that constitute said first and second imaging optical systems are formed of synthetic quartz.