Phase-shifting interferometry method and system
US6924898B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 2002 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Jul 21, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An interferometry method including: i) forming an optical interference image by combining different portions of an optical wave front reflected from multiple surfaces; ii) recording an interference signal at different locations of the optical interference image in response to varying a property of the optical wave front that causes pairs of the multiple surfaces that have different optical path separations to contribute differently to the interference signal; iii) transforming the interference signal for at least one of the locations to produce a spectrum having a peak at a spectral coordinate corresponding to each pair of the multiple surfaces; and iv) identifying the spectral coordinate of the peak corresponding to a selected pair of the multiple surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.