Fabry–Perot optical fiber strainmeter with an embeddable, low-power interrogation system
| Autor: | Mikhael de Mengin, Olivier Coutant, Etienne Le Coarer |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Optical fiber
Materials science business.industry Physics::Optics Spectral density Earth tide Strainmeter Atomic and Molecular Physics and Optics Physics::Geophysics Electronic Optical and Magnetic Materials law.invention Interferometry Optics Fiber Bragg grating Fiber optic sensor law business Fabry–Pérot interferometer |
| Zdroj: | Optica. 2:400 |
| ISSN: | 2334-2536 |
| DOI: | 10.1364/optica.2.000400 |
| Popis: | Detection of earthquakes and tidal variations via measurement of strain in the Earth’s crust requires compact and robust instrumentation with low power usage that can be deployed in the field. Here we demonstrate a stationary-wave integrated Fourier transform spectrometer (SWIFTS) and measure the variations induced by ground strain on an optical fiber Bragg grating sensor using two short (17±2 mm) Fabry–Perot (FP) cavities, one for the sensor, and one for temperature compensation. The SWIFTS delivers spatial interferograms that are then Fourier transformed to deduce the deformation from a cross-spectral analysis of the FP spectra. The full system is tested in field conditions to record crustal earth strain signals and successfully detect the earth tide and an earthquake signal. With this low-coherency interferometry technique, this system offers an excellent compromise between the resolution needed and the cost of a fully autonomous field instrument. |
| Databáze: | OpenAIRE |
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