Constantly high sensitivity fiber optic interferometer sensor
US6166815A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1996 |
| Grant date | Dec 26, 2000 |
| Priority date | — |
| Expiry date | Apr 18, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B9/02007
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber optic interferometric sensor (150) having constantly high sensitivity by use of two lasers (152, 154) that simultaneously output at first and second wavelengths. By judicious choice of the wavelengths, the optical path length difference between the two interferometer paths (164, 166) can be kept near the maximum slope of the interference fringes for one or the other of the wavelengths. The output from the interferometer (160) is divided between first and second detector arms (170, 130). A filter (172) in the first detector arm passes the first wavelength and rejects the second. A filter (182) in the second detector arm passes the second wavelength and rejects the first. A first detector (174) at the output of the first detector arm reads the interference pattern at the first wavelength. A second detector arm reads the interference pattern at the second wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.