High spatial and temporal resolution interrogation of fully distributed chirped fiber Bragg grating sensors


A novel interrogation technique for fully distributed linearly chirped fiber Bragg grating (LCFBG) strain sensors with simultaneous high temporal and spatial resolution based on optical time-stretch frequency-domain reflectometry (OTS-FDR) is proposed and experimentally demonstrated. LCFBGs is a promising candidate for fully distributed sensors thanks to its longer grating length and broader reflection bandwidth compared to normal uniform FBGs. In the proposed system, two identical LCFBGs are employed in a Michelson interferometer setup with one grating serving as the reference grating whereas the other serving as the sensing element. Broadband spectral interferogram is formed and the strain information is encoded into the wavelength-dependent free spectral range (FSR). Ultrafast interrogation is achieved based on dispersion-induced time stretch such that the target spectral interferogram is mapped to a temporal interference waveform that can be captured in real-Time using a single-pixel photodector. The distributed strain along the sensing grating can be reconstructed from the instantaneous RF frequency of the captured waveform. High-spatial resolution is also obtained due to high-speed data acquisition. In a proof-of-concept experiment, ultrafast real-Time interrogation of fully-distributed grating sensors with various strain distributions is experimentally demonstrated. An ultrarapid measurement speed of 50 MHz with a high spatial resolution of 31.5 μm over a gauge length of 25 mm and a strain resolution of 9.1 μϵ have been achieved.

Publication DOI: https://doi.org/10.1109/JLT.2016.2605401
Divisions: College of Engineering & Physical Sciences > Aston Institute of Photonics Technology (AIPT)
Additional Information: © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Uncontrolled Keywords: chromatic dispersion,fiber Bragg grating,Fourier transforms,frequency-domain reflectometry,optical interferometry,time stretch,Atomic and Molecular Physics, and Optics
Publication ISSN: 0733-8724
Last Modified: 03 Jun 2024 07:23
Date Deposited: 20 Oct 2016 07:25
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2017-08-15
Published Online Date: 2016-09-01
Accepted Date: 2016-08-15
Submitted Date: 2016-05-16
Authors: Ahmad, Eamonn J.
Wang, Chao
Feng, Dejun
Yan, Zhijun
Zhang, Lin (ORCID Profile 0000-0002-1691-5577)



Version: Accepted Version

Export / Share Citation


Additional statistics for this record