scholarly journals Distributed Fiber Birefringence Measurement Using Pulse-Compression Φ-OTDR

2020 ◽  
Author(s):  
Yongxiang Chen ◽  
Yun Fu ◽  
Ji Xiong ◽  
Zinan Wang
Keyword(s):  
Spatial Resolution ◽  
Pulse Compression ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Time Domain Reflectometry ◽  
Coherent Detection ◽  
Compression Phase ◽  
Optical Time Domain Reflectometry ◽  
Fiber Birefringence ◽  
Optical Time

Abstract In this paper, a novel birefringence measurement method through the Rayleigh backscattered lightwave within single-mode fiber is proposed, using a single chirped-pulse with arbitrary state of polarization. Numerical analysis is carried out in detail, then pulse-compression phase-sensitive optical time domain reflectometry (PC-Φ-OTDR) with polarization-diverse coherent detection is employed to verify this method. A 2km spun single-mode fiber is tested with 8.6 cm spatial resolution, and the average birefringence of the fiber under test is measured as 0.234rad/m, which is consistent with previous literatures about single-mode fiber. Moreover, the relationship between the measured birefringence and the spatial resolution is also studied for the first time, and the results show that spatial resolution is crucial for fiber birefringence measurement.

scholarly journals Sub-Meter Spatial Resolution Phase-Sensitive Optical Time-Domain Reflectometry System Using Double Interferometers

2018 ◽  
Vol 8 (10) ◽  
pp. 1899 ◽  
Author(s):  
Shengwen Feng ◽  
Tuanwei Xu ◽  
Jianfen Huang ◽  
Yang Yang ◽  
Lilong Ma ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Bilateral Filtering ◽  
Rayleigh Backscattering ◽  
Detection Frequency ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Optical Time ◽  
Phase Generated Carrier

An improved phase-sensitive optical time-domain reflectometry (φ-OTDR) system with sub-meter spatial resolution is demonstrated. Two Michelson interferometers (MIs) with different path length differences are used in the proposed system. One is 10 m, the other is 9.2 m. Two Rayleigh backscattering phase traces with different spatial resolution are obtained by a phase generated carrier (PGC) algorithm at adjacent times. After using differencing and adaptive 2-D bilateral filtering algorithms, a 0.8-m spatial resolution over 2 km is achieved. Experimental results indicate that the system shows an extraordinary linearity as high as 99.94% with amplitude-modulation and acquires a detection frequency from 5 to 500 Hz.

scholarly journals Performance Optimization for Phase-Sensitive OTDR Sensing System Based on Multi-Spatial Resolution Analysis

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 83 ◽  
Author(s):  
Yuanyuan Shan ◽  
Wenbin Ji ◽  
Qing Wang ◽  
Lu Cao ◽  
Feng Wang ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Performance Optimization ◽  
Signal To Noise Ratio ◽  
Time Domain Reflectometry ◽  
Sensing System ◽  
Optical Time Domain Reflectometry ◽  
Resolution Analysis ◽  
Phase Sensitive ◽  
Optical Time ◽  
Qualitative Relationship

This paper proposes and demonstrates a phase-sensitive optical time domain reflectometry (Φ-OTDR) sensing system with multi-spatial resolution (MSR) analysis property. With both theoretical analysis and an experiment, the qualitative relationship between spatial resolution (SR), signal-to-noise ratio (SNR) and the length of the vibration region has been revealed, which indicates that choosing a suitable SR to analyze the vibration event can effectively enhance the SNR of a sensing system. The proposed MSR sensing scheme offers a promising solution for the performance optimization of Φ-OTDR sensing systems, which can restore vibration events of different disturbance range with optimum SNR in merely a single measurement while maintaining the same detectable frequency range.

scholarly journals Fiber Optic Based Distributed Mechanical Vibration Sensing

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4779
Author(s):  
Vít Novotný ◽  
Petr Sysel ◽  
Aleš Prokeš ◽  
Pavel Hanák ◽  
Karel Slavíček ◽  
...  
Keyword(s):  
Mechanical Vibration ◽  
Single Mode ◽  
Time Domain Reflectometry ◽  
Sensing System ◽  
Optical Time Domain Reflectometry ◽  
Measurement Results ◽  
Vibration Sensing ◽  
Phase Sensitive ◽  
Optical Time ◽  
Initial Measurement

The distributed long-range sensing system, using the standard telecommunication single-mode optical fiber for the distributed sensing of mechanical vibrations, is described. Various events generating vibrations, such as a walking or running person, moving car, train, and many other vibration sources, can be detected, localized, and classified. The sensor is based on phase-sensitive optical time-domain reflectometry (ϕ-OTDR). Related sensing system components were designed and constructed, and the system was tested both in the laboratory and in the real deployment, with an 88 km telecom optical link, and the results are presented in this paper. A two-fiber sensor unit, with a double-sensing range was also designed, and its scheme is described. The unit was constructed and the initial measurement results are presented.

Proposal of Pulse Compression Brillouin Optical Time Domain Reflectometry

2021 ◽  
Author(s):  
Pengbai Xu ◽  
Xinyong Dong ◽  
Jun Yang ◽  
Yuwen Qin ◽  
Chao Pang ◽  
...  
Keyword(s):  
Time Domain ◽  
Pulse Compression ◽  
Time Domain Reflectometry ◽  
Optical Time Domain Reflectometry ◽  
Optical Time
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