Open AccessDistributed refractive index sensing based on tapered fibers in optical frequency domain reflectometry
Author(s) -
Zhenyang Ding,
Keliang Sun,
Kun Liu,
Junfeng Jiang,
Decai Yang,
Zhe Yu,
Jing Li
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.013042
Subject(s) - reflectometry , optics , refractive index , materials science , optical fiber , image resolution , fiber optic sensor , normalized frequency (unit) , reflection (computer programming) , time domain , physics , phase noise , phase locked loop , frequency synthesizer , computer science , computer vision , programming language
We present a distributed refractive index (RI) sensor using tapered optical fibers in optical frequency domain reflectometry (OFDR). RI of the external medium surrounding the tapered optical fibers is measured by the optical frequency shifts of the local back-reflection spectra in OFDR. By a spectrum interpolation, we can increase the resolution of RI measurements without decreasing the sensing spatial resolution. In our experiments, we realize a truly distributed RI sensing with a 4.25 mm spatial resolution and 2.1 cm measurement distance. We calibrate the relationship between the optical frequency shifts of the local back-reflection spectra and RI variation. RI ranges from 1.3574 to 1.3686 and the sensitivity is about 8565 GHz/RIU (68.52 nm/RIU) in the presented sensor. We also measure RI variation in a glycerol solution diffusion to verify the capability of distributed RI sensing by the presented sensor.