| 摘要 |
PROBLEM TO BE SOLVED: To provide a catadioptric optical system with a high numerical aperture.SOLUTION: An optical system includes a first optical group which forms, on a first intermediate image plane, a first intermediate image of an object located on an object plane, and second and third optical groups which form a final object image on an image plane from the first intermediate image. The first optical group comprises a solid lens which has a first surface and a concave second surface opposite the first surface. The solid lens collects light from the object and internally reflects the collected light at least twice. The second optical group includes at least one Mangin mirror and the third optical group includes a plurality of lenses. The first, second, and third optical groups are capable of appropriately controlling axial chromatic aberration and Petzval curvature, and thus capable of forming an image using high NA illumination. |
