System and method for measuring an optical path difference in a sensing interferometer
US6842254B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2002 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Jul 25, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/45
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and a method of measuring an optical path difference in a sensing interferometer. Light from a source is directed in the sensing interferometer. The light reflected from the sensing interferometer is splitted into first and second beams respectively directed into two reference interferometers having optical path differences greater than the coherence length of the source and such that the optical signals are in quadrature. The intensities of the light transmitted by the reference interferometers and recombined light reflected from the reference interferometers are detected for measuring the optical path difference in the sensing interferometer. Additional light sources allow for correction of internal perturbations and absolute measurement of the optical path difference in the sensing interferometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.