
Tapered GRIN fiber microsensor
Author(s) -
Felipe BeltránMejía,
Claudecir R. Biazoli,
Cristiano M. B. Cordeiro
Publication year - 2014
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.030432
Subject(s) - tapering , optics , materials science , multi mode optical fiber , sensitivity (control systems) , optical fiber , refractive index , fiber optic sensor , graded index fiber , wavelength , single mode optical fiber , optical path length , physics , electronic engineering , computer graphics (images) , computer science , engineering
The sensitivity of an optical fiber microsensor based on inter-modal interference can be considerably improved by tapering a short extension of the multimode fiber. In the case of Graded Index fibers with a parabolic refractive index profile, a meridional ray exhibits a sinusoidal path. When these fibers are tapered, the period of the propagated beam decrease down-taper and increase up-taper. We take advantage of this modulation -along with the enhanced overlap between the evanescent field and the external medium- to substantially increase the sensitivity of these devices by tuning the sensor's maximum sensitivity wavelength. Moreover, the extension of this device is reduced by one order of magnitude, making it more propitious for reduced space applications. Numerical and experimental results demonstrate the success and feasibility of this approach.