title: Dual-modulation fiber Fabry-Perot interferometer with double reflection for slowly-varying displacements.
abstract: This Letter describes a dual-amplitude modulation technique incorporated into a double reflection extrinsic-type fiber Fabry-Perot interferometer to measure periodic, nonperiodic as well as quasi-static displacements. The modulation scheme simultaneously maintains the interference signal pair in quadrature and provides a reference signal for displacements inferior to a quarter of the source wavelength. The control and phase demodulation of the interferometer carried out via software enable quasi-real-time measurement and facilitates sensor alignment. The sensor system can be exploited in the low frequency range from 10(-3) to ∼500 Hz and has a resolution better than 2.2 nm, targeting applications in geophysics.
authors: CNRS, LAAS, F-31077 Toulouse, France. seat@enseeiht.fr
authors: H C
authors: HC
authors: Seat
authors: P
authors: P
authors: Chawah
authors: M
authors: M
authors: Cattoen
authors: A
authors: A
authors: Sourice
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authors: Plantier
authors: F
authors: F
authors: Boudin
authors: J
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authors: Chéry
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authors: Brunet
authors: P
authors: P
authors: Bernard
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authors: Suleiman