Multiplexable fiber-optic strain sensor system with temperature compensation capability
US6597822B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1999 |
| Grant date | Jul 22, 2003 |
| Priority date | — |
| Expiry date | Apr 2, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/29398
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fiber optic sensor comprises two independent fibers having Bragg gratings which are coupled to commutating broadband optical sources through splitters and wavelength discriminators. The ratio of detected optical energy in each of two detectors examining the wave intensity returned to a wavelength discriminator coupled with the characteristic of the wavelength discriminator determines the wavelength returned by the grating. In another embodiment, tunable filters are utilized to detect minimum returned wave energy to extract a sensor wavelength. Reference to the original grating wavelength indicates the application of either temperature or strain to the grating. In another embodiment, a plurality of Bragg grating sensor elements is coupled to sources and controllers wherein a dimensional change in a fiber having a Bragg grating is detected using a measurement system comprising broad-band sources, optical power splitters, a high-sensitivity wavelength discriminator, optical detectors, and a controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.