A Fiber Fabry-Perot Interferometer for Geophysics Applications

Han Cheng Seat (1, 2) , Michel Cattoen (1, 2) , Françoise Lizion (1, 2) , M. Suleiman (3) , F Boudin (4) , J Chéry (4) , C Brunet (5) , Patrick Bernard (5) , P Chawah (6, 7) , A Sourice (6, 7) , Guy Plantier (6, 7) , D Boyer (8, 9) , A Cavaillou (8, 9) , S Gaffet (8, 9)

1 LAAS - Laboratoire d'analyse et d'architecture des systèmes
2 LAAS-OSE - Équipe Optoélectronique pour les Systèmes Embarqués
3 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
4 Géosciences Montpellier
5 IPGP - Institut de Physique du Globe de Paris
6 GSII - ESEO-GSII
7 LAUM - Laboratoire d'Acoustique de l'Université du Mans
8 LSBB - Laboratoire Souterrain à Bas Bruit
9 GEOAZUR 7329 - Géoazur

A fiber interferometer interfaced to 3 geo-mechanical elements is presented for applications in geophysics. The fiber sensor is based on an extrinsic fiber Fabry-Perot interferometer (EFFPI) which incorporates a modulation scheme to lock the interferometer at quadrature and to enable displacement measurements below a quarter of the interrogating wavelength. It operates over a relatively large frequency dynamic of ~500000 with a precision better than 2 nm. The fiber interferometer is next interfaced to a differential hydrostatic long baseline inclinometer, a 3-axis borehole tiltmeter and a single-axis seismometer, respectively. Results obtained demonstrate that the fiber interferometrically-interrogated instruments exhibit performances equivalent to or even surpassing those of the reference instruments employed for comparison during their deployment to an underground test site since March 2012. Keywords—modulation-based extrinsic fiber Fabry-Perot interferometer; fiber optique hydrostatic inclinometer; fiber optique borehole tiltmeter; fiber optique seismometer

Domaines: Sciences de l'ingénieur [physics]

Han Cheng Seat, Michel Cattoen, Françoise Lizion, M. Suleiman, F Boudin, et al.. A Fiber Fabry-Perot Interferometer for Geophysics Applications. IEEE SENSORS 2015, Nov 2015, Busan, South Korea. ⟨10.1109/ICSENS.2015.7370316⟩. ⟨hal-01265963⟩