Paper
1 November 2021 Vibration detection and reconstruction based on Φ-OTDR with dual AOM
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Proceedings Volume 12057, Twelfth International Conference on Information Optics and Photonics; 120570A (2021) https://doi.org/10.1117/12.2603937
Event: Twelfth International Conference on Information Optics and Photonics, 2021, Xi'an, China
Abstract
In the current practical application, the signal of the balance detector in Φ-OTDR system is transmitted at about 100MHz, with the A/D sampling rate is usually above 2GS/s, which requires higher requirements on acquisition equipment and signal processing equipment. The cost and stability of its equipment could not be completed. In order to solve this kind of problem, a phase-sensitive optical time-domain reflectometric (Φ-OTDR) system based on dual AOM which add frequency shift structure for local oscillator light is proposed. This system could obtain the position information and timefrequency characteristics of vibration signal simultaneously under lower sampling frequency by reducing the frequency shift of the backward-scattering Rayleigh light signal. Under the condition of low sampling rate, the initial impulse energy loss is reduced to improve the quantitative analysis ability of disturbance signals. The experimental results show that the spatial resolution of 5m is achieved on the 1.43km sensing fiber, the details of the original backscatter Rayleigh signal could appear as a sinusoidal signal and impulse energy of them is stronger. After noise reduction, the SNR could be increased from 10.37dB to 20.59dB for signal reconstruction with a disturbance frequency of 500Hz. The improvement of the SNR indicates that the Φ-OTDR detection of the dual AOM is feasible and effective in the detection of weak stress signal monitoring at low sampling rate.
© (2021) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Bei Dai, Zhihua Yu, Ao Chen, and Yutong Li "Vibration detection and reconstruction based on Φ-OTDR with dual AOM", Proc. SPIE 12057, Twelfth International Conference on Information Optics and Photonics, 120570A (1 November 2021); https://doi.org/10.1117/12.2603937
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KEYWORDS
Signal detection

Bragg cells

Signal to noise ratio

Heterodyning

Optical fibers

Sensors

Backscatter

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