Multiplexed Bragg grating sensors
US5426297A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1993 |
| Grant date | Jun 20, 1995 |
| Priority date | — |
| Expiry date | Sep 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/35383
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A measurement system for fiber sensors includes a broadband light source 11 providing continuous light which is launched into a fiber 20 having a plurality (or string) of Bragg grating sensors 24, 28, 34. Each sensor has a predetermined central reflection wavelength which shifts as a function of applied strain. Reflected light 40 from the sensors 24, 28, 34 are fed to a plurality of optical bandbass filters 50, 64, 78, each having a monotonic region in a passband corresponding to one of the sensors. Each monotonic region transmits the reflected wavelength from a corresponding sensor. Light 52, 66, 80 is passed from the filters 50, 64, 78 to optical detectors 54, 68, 82 each providing an electrical signal having a magnitude related to transmission of the filter at the reflection wavelength of the sensor. Optional demodulators 58, 72, 86 are connected to each of the detectors 54, 68, 82 if the light source 10 is modulated. Such modulation provides noise immunity and allows demultiplexing of several strings of sensors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.