Study on the simultaneous distributed measurement of temperature and strain based on Brillouin scattering in dispersion-shifted fiber

Abstract

Utilizing the large effective area non-zero dispersion-shifted fiber (LEAF), a multi-parameter optical-fiber sensor has been proposed and experimentally demonstrated for distributed simultaneous temperature and strain measurement, which is based on multiple acoustic modes in spontaneous Brillouin scattering (SpBS) effect. Proof-of-concept experiments demonstrate 3 m spatial resolution over 2.5 km sensing LEAF with 2°C temperature accuracy and 60µɛ strain accuracy. The proposed distributed Brillouin optical fiber sensor allows simultaneously temperature and strain measurement, thus opening a door for practical application such as superconducting cable.

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

“…In experiment, the sensitivities of the fundamental acoustic mode are 1.16 MHz/°C and 0.0646 MHz/με, respectively. Moreover, by analysing the temperature and strain coefficients of different acoustic modes, discrimination of temperature and strain are successfully demonstrated with a temperature measurement accuracy of 1.02°C and a strain measurement accuracy of 19.68 με in 2.5 km sensing range, which is about three times enhancement compared with the LEAF fiber-based method [19].…”

“…As the laser sources usually work in the fundamental mode, it might add extra difficulties to convert the fundamental mode into the desired spatial mode. Sheng et al [19] propose a novel technique based on the BOTDR scheme, which employs a large effective area nonzero dispersion-shifted fiber (LEAF) with four Brillouin peaks as the sensing fiber to solve the cross-sensitivity problem. Remarkably, most of the distributed fiberoptic sensor using Brillouin scattering is based on standard SMF with acrylate coating, which can sustain a maximum temperature of +85°C.…”

Simultaneous Temperature and Acoustic Sensing with Coherent Correlation OTDR

“…The advantage of such fibers is that different scattering processes like Rayleigh, Brillouin and Raman scattering can be exploited to measure different physical parameters. For instance, the frequency dependency of spontaneous Brillouin scattering on temperature and strain has been utilized to measure these parameters simultaneously in different locations [2]. However, the presented strategy is accompanied by increased costs since a frequency shift needs to be realized in the reference path.…”

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.…”