Self-Mixing Demodulation for Coherent Phase-Sensitive OTDR System
AbstractPhase-sensitive optical time domain reflectometry (Ф-OTDR) attracts much attention due to its capability of telling the type and position of an intrusion simultaneously. In recent decades, coherent Ф-OTDR has been demonstrated to realize long-distance detection. For coherent Ф-OTDR, there are three typical demodulation schemes in the reported studies. However, they still cannot realize real-time monitoring to satisfy practical demands. A simple and effective demodulation method based on self-mixing has been put forward to demodulate the beat signal in coherent Ф-OTDR. It not only saves a local electrical oscillator and frequency locked loop, but also demodulates the beat signal without residual frequency. Several vibrations with different frequency were separately applied at the same location of a 42.5 km fiber. The spatial resolution of 10 m and frequency response range from 8 Hz to 980 Hz have been achieved. The precise location with signal-to-noise ratio of 21.4 dB and broadband measurement demonstrate the self-mixing scheme can demodulate the coherent Ф-OTDR signal effectively. View Full-Text
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He, H.; Shao, L.-Y.; Li, Z.; Zhang, Z.; Zou, X.; Luo, B.; Pan, W.; Yan, L. Self-Mixing Demodulation for Coherent Phase-Sensitive OTDR System. Sensors 2016, 16, 681.
He H, Shao L-Y, Li Z, Zhang Z, Zou X, Luo B, Pan W, Yan L. Self-Mixing Demodulation for Coherent Phase-Sensitive OTDR System. Sensors. 2016; 16(5):681.Chicago/Turabian Style
He, Haijun; Shao, Li-Yang; Li, Zonglei; Zhang, Zhiyong; Zou, Xihua; Luo, Bin; Pan, Wei; Yan, Lianshan. 2016. "Self-Mixing Demodulation for Coherent Phase-Sensitive OTDR System." Sensors 16, no. 5: 681.
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