Distributed Fiberoptic Sensor for Simultaneous Temperature and Strain Monitoring Based on Brillouin Scattering Effect in Polyimide-Coated Fibers

Abstract

A unique multiparameter sensor for distributed measurement of temperature and strain based on spontaneous Brillouin scattering in polyimide-coated optical fiber is proposed, which is an excellent candidate for the cross-sensitivity problem in conventional Brillouin sensing network. In the experimental section, the discrimination of strain and temperature is successfully demonstrated by analysing the unequal sensing coefficients of the Brillouin frequency shifts generated by different acoustic modes. The Brillouin frequency shifts of the main two peaks are successfully measured to discriminate the strain and temperature with an accuracy 19.68 με and 1.02°C in 2.5 km sensing range. The proposed distributed Brillouin optical fiber sensor allows simultaneous measurement of temperature and strain, thus opening a door for practical application such as oil explorations.

Simultaneous Measurement of Distributed Temperature and Strain through Brillouin Frequency Shift Using a Common Communication Optical Fiber

“…Compared with traditional electrical sensing systems, the fiber-distributed sensing network provides an interesting solution due to the following main advantages: low cost, compactness, high sensitivity, immunity to external-electromagnetic interference, intrinsic chemical inertness, and long sensing range, where the fiber simultaneously serves as the interrogate signal transmission medium and a large number of closely spaced sensing points. To date, many different technologies have been developed, including Raman distributed temperature sensor (RDTS) [7,8], Brillouin reflectometers (optical correlation domain (BOCDR), optical frequency domain (BOFDR), optical time domain (BOTDR)) [9][10][11][12][13][14], Brillouin analyzers (BOCDA, BOFDA, and BOTDA) [15][16][17], and Rayleigh reflectometer (optical frequency domain (OFDR)) [18]. Among these techniques, BOTDR, which is based on the spontaneous Brillouin scattering (SpBS) effect, is considered as one of the most potential sensing techniques that can simultaneously retrieve distributed temperature and strain information by single-ended fiber under test (FUT) architecture and random accessibility.…”

Distributed Temperature Sensing System Based on Brillouin Scattering Effect Using a Single-Photon Detector

“…ese Brillouin-based distributed fiberoptic sensors can mainly be split into two classes: the Brillouin reflectometer (optical time domain-BOTDR) [11][12][13] and Brillouin analyzer (optical time domain-BOTDA) [14][15][16]. Among them, the first type (BOTDR) is considered as one of the most promising techniques that can retrieve distributed ambient temperature information by single-ended fiber under test (FUT) architecture, large dynamic range, and random accessibility.…”