Methods and apparatus for reducing error in interferometric imaging measurements
US7184149B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 2004 |
| Grant date | Feb 27, 2007 |
| Priority date | — |
| Expiry date | Aug 22, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/254
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a method and apparatus for reducing error in interferometric fringe stability and reproducibility in an interference fringe generator. In one aspect, the method for reducing error in interferometric fringe stability and reproducibility includes providing a light source, positioning a grating to receive light from the light source and positioning a projection lens having a focal length F to receive light from the grating. The projection lens projects the received light upon an object of interest positioned substantially at a distance d1 from the lens. Typically the lens is positioned substantially at a distance d2 from the grating. The values of d1, d2, and F are related by d2 being approximately equal to d1F/(d1−F).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.