Optical imaging systems and methods using polarized illumination and coordinated pupil filter
US6965484B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 2003 |
| Grant date | Nov 15, 2005 |
| Priority date | — |
| Expiry date | Sep 12, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70308
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Optical imaging systems and methods use polarized illumination and a coordinated pupil filter to achieve high contrast. An imaging system includes a light source to generate light for illuminating an object having features aligned in a first direction and features aligned in a second direction, a lens for imaging the illuminated object onto a surface, a spatial selection device, such as a pupil filter, selective in a first mode of light corresponding to features of the illuminated object aligned in the first direction and selective in a second mode of light corresponding to features of the illuminated object aligned in a second direction, a polarization device optically coupled to the spatial selection device and selective in the first mode of s-polarized light corresponding to the first direction and selective in the second mode of s-polarized light corresponding to the second direction, and a controller for selecting operation in the first mode or in the second mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.