Distributed Fiber-Optic Sensors for Vibration Detection

Abstract

Distributed fiber-optic vibration sensors receive extensive investigation and play a significant role in the sensor panorama. Optical parameters such as light intensity, phase, polarization state, or light frequency will change when external vibration is applied on the sensing fiber. In this paper, various technologies of distributed fiber-optic vibration sensing are reviewed, from interferometric sensing technology, such as Sagnac, Mach–Zehnder, and Michelson, to backscattering-based sensing technology, such as phase-sensitive optical time domain reflectometer, polarization-optical time domain reflectometer, optical frequency domain reflectometer, as well as some combinations of interferometric and backscattering-based techniques. Their operation principles are presented and recent research efforts are also included. Finally, the applications of distributed fiber-optic vibration sensors are summarized, which mainly include structural health monitoring and perimeter security, etc. Overall, distributed fiber-optic vibration sensors possess the advantages of large-scale monitoring, good concealment, excellent flexibility, and immunity to electromagnetic interference, and thus show considerable potential for a variety of practical applications.

Evreuyumlu Algilama Tabanli Faz-Otdr Sorgulayici Üni̇te Geli̇şti̇ri̇lmesi̇

“…where operator represents absolute value, stands for the pulse repetition period (the time between two successive pulses, =1/PRF). Assuming a periodic vibration which gives rise to a phase change having a maximum value of , and for a known pulse repetition rate, the maximum detectable vibration frequency that meets the requirement of (6) can be calculated as † (7) The relationship between the electrical signal applied on the PZT ( ) and the corresponding phase change occurring in the optical signal ( ) can be calculated based on the specifications of the particular PZT used in the experiments (cf. Table 3).…”

An In-Line Fiber Optic Fabry–Perot Sensor for High-Temperature Vibration Measurement

“…High-temperature vibration sensors are essential for the maintenance and fault detection of facilities and equipment in many fields, such as aerospace, oil and gas pipeline transportation, volcanic seismic activity detection, coal ore mining, and other fields, as well as the health monitoring of structures [1][2][3][4][5]. Fiber optic vibration sensors have been proven to have good application prospects in high-temperature measurement in past research, and they have the advantages of small size, high accuracy, and resistance to electromagnetic interference [6][7][8][9][10][11]. The fiber optic vibration sensors are mainly based on fiber Bragg gratings (FBGs), Mach-Zehnder interferometers, or Fabry-Perot (FP) interferometers.…”

94.8 Km-Range Direct Detection Fiber Optic Distributed Acoustic Sensor

“…Phase-sensitive optical time domain reflectometry (φ-OTDR) based distributed acoustic sensors (DAS) have been utilized as a powerful tool for real-time monitoring of oil and gas pipelines, intrusion detection, critical facility security, various vibration measurements and so on [1]. For linear assets monitoring, such as pipeline and national borderline security, ultra-long range distributed sensors are desired.…”