Diameter and tensile strain measurements of optical nanofibers using Brillouin reflectometry

Adrien Godet (1) , Abdoulaye Ndao (1) , Vincent Pêcheur (1) , Sylvie Lebrun (2) , Gilles Pauliat (2) , Jean Beugnot (1) , Kien Phan Huy (1) , Thibaut Sylvestre (1)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
2 Laboratoire Charles Fabry / Manolia

We demonstrate a simple and efficient technique that allows for a complete characterization of silica-based tapered optical fibers with sub-wavelength diameters ranging from 0.5 μm to 1.2 μm. The technique is based on Brillouin reflectometry using a single-ended heterodyne detection. It has a high precision sensitivity down to 1% owing to the strong dependence of the Brillouin spectrum on the taper diameter. We further investigate the tensile strain dependence of the Brillouin spectrum for an optical microfiber up to 5% of elongation. The results show strong dependences of several Brillouin resonances with different strain coefficients ranging from 290 MHz/% to 410 MHz/% with a specific nonlinear deviation at high strain. Those results therefore show that optical micro and nanofibers could find potential application for sensitive strain optical sensing.

Domaines: Optique [physics.optics]

Adrien Godet, Abdoulaye Ndao, Vincent Pêcheur, Sylvie Lebrun, Gilles Pauliat, et al.. Diameter and tensile strain measurements of optical nanofibers using Brillouin reflectometry. SPIE Photonics Europe, 10681, pp.106810K, 2018, Proceedings SPIE, ⟨10.1117/12.2306838⟩. ⟨hal-02389046⟩