Phase-Sensitive Optical Time Domain Reflectometer Based on Phase-Generated Carrier Algorithm
Phase-Sensitive Optical Time Domain Reflectometer Based on Phase-Generated Carrier Algorithm
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DOI：
10.1109/jlt.2015.2414416
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发表时间：
2015-07-01
影响因子：
4.7
通讯作者：
Li, Fang
中科院分区：
文献类型：
--
作者：
Fang, Gaosheng;Xu, Tuanwei;Li, Fang
提出了一种基于相敏光时域反射计(Phi-OTDR)和相位产生载波解调算法的分布式光纤传感系统。在系统的接收端引入了非平衡迈克尔逊干涉仪。来自传感光纤某一位置的背向瑞利散射光将干涉产生随时间变化的干涉光信号，干涉光信号的相位携带传感信息。提出并实现了相位产生载波解调算法来恢复相位信息。在传感光纤的某一位置施加单频振动事件，实现了对单频振动事件的正确解调。相敏OTDR系统的噪声电平约为3×10~(-3)rad/根赫兹，信噪比约为30.45分贝。PHI-OTDR系统的最大传感长度和空间分辨率分别为10 km和6m，脉冲重复频率为10 kHz，在MI中具有6m的光纤延迟，询问脉冲宽度为30 ns。
We propose a novel approach to generate distributed fiber sensing system based on phase-sensitive optical time domain reflectometer (Phi-OTDR) and phase-generated carrier demodulation algorithm. An unbalanced Michelson interferometer is introduced at the receiving end of the system. The back Rayleigh scattering light from a certain position along the sensing fiber would interfere to generate interference light signal versus time, whose phase carries the sensing information. Phase-generated carrier demodulation algorithm is proposed and carried out to recover the phase information. A single frequency vibration event is applied to a certain position along the sensing fiber and we realize to demodulate it correctly. The noise level of the phase sensitive OTDR system is about 3 x 10(-3) rad/root Hz and a signal to noise ratio about 30.45 dB is achieved. The maximum sensing length and the spatial resolution of the Phi-OTDR system are 10 km and 6 m with pulse repetition rate at 10 kHz and 6 m fiber delay in MI with interrogating pulse width of 30 ns.