High NA system for multiple mode imaging
US6064517A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Mar 24, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70616
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system for multiple mode imaging is disclosed herein. The system is a catadioptric system preferably having an NA greater than 0.9, highly corrected for low and high order monochromatic aberrations. This system uses unique illumination entrances and can collect reflected, diffracted, and scattered light over a range of angles. The system includes a catadioptric group, focusing optics group, and tube lens group. The catadioptric group includes a focusing mirror and a refractive lens/mirror element. The focusing optics group is proximate to an intermediate image, and corrects for aberrations from the catadioptric group, especially high order spherical aberration and coma. The tube lens group forms the magnified image. Different tube lens groups can be used to obtain different magnifications, such as a varifocal tube lens group to continuously change magnifications from 20 to 200.times.. Multiple imaging modes are possible by varying the illumination geometry and apertures at the pupil plane. Imaging modes include bright-field, full sky, ring dark-field, inverted ring dark-field, directional dark-field, double dark-field, Manhattan geometry, confocal bright-field, confocal dark-fiel…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.