Detector configuration for interferometric distance measurement
US7379187B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 2006 |
| Grant date | May 27, 2008 |
| Priority date | — |
| Expiry date | Jul 20, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A phase difference detector generates a plurality of signals from an input beam including orthogonal, linearly polarized object and reference beam components. The detector may be configured such that as the reference and object beam components traverse the detector, phase shifts due to surface interactions are made as similar as possible between the s-components of the reference object beams, and between the p-components of the reference and object beams. Various outputs may be formed by interfering p-components exclusively, or s-components exclusively, negating errors that may otherwise arise due to differential phase shifts between p- and s-components. Phase-shifting elements in the detector may receive beams from beam splitting surfaces where the transmissive differential phase shift between p- and s-components is adjusted to insignificance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.