Sensing apparatus and method for detecting strain between fiber bragg grating sensors inscribed into an optical fiber
US5748312A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1995 |
| Grant date | May 5, 1998 |
| Priority date | — |
| Expiry date | Sep 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/35354
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensing apparatus and related method for sensing strain between fiber Bragg grating sensors inscribed in an optical fiber. The fiber is inscribed with a first fiber Bragg grating sensor and a second fiber Bragg grating sensor. A strain detection unit detects strain between the first fiber Bragg grating sensor and the second fiber Bragg grating sensor based on the optical propagation time of light projected into the fiber and reflected by the first fiber Bragg grating sensor and the optical propagation time of light projected into the fiber and reflected by the second fiber Bragg grating sensor. More specifically, light projected into the fiber is modulated with an RF signal. A phase change of the RF signal is determined from the light projected into the fiber and reflected by the first fiber Bragg grating sensor and from the light projected into the fiber and reflected by the second fiber Bragg grating sensor. The phase change of the RF signal is related to the optical propagation time of light projected into the fiber and reflected by the first and second fiber Bragg grating sensors. The strain between the first and second fiber Bragg grating sensors is then determined from the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.