Tilted Bragg grating multipoint sensor based on wavelength-gated cladding-modes coupling.
In recent years, tilted fiber Bragg gratings (TFBGs) have been demonstrated to be a promising technological platform for sensing applications such as the measurement of axial strain, bending, vibration, and refractive index. However, complex spectral measurements combined with the difficulty of using TFBGs in a quasi-distributed sensors network limit the practical exploitation of this assessed technology. To address this issue, we propose a hybrid configuration involving uniform and TFBGs working in reflection, which makes the demodulation technique easier and allows multipoint sensing. This configuration provides a narrowband reflection signal that is modulated by the wavelength selective losses associated with some TFBG's cladding-modes resonances. We report here the operating principle of the proposed device. An experimental validation is presented for refractive-index sensing purposes.
Caucheteur
Christophe
C
Electromagnetism and Telecommunication Unit, Faculté Polytechnique de Mons, Mons 7000, Belgium. christophe.caucheteur@umons.ac.be
Mégret
Patrice
P
Cusano
Andrea
A