It has been shown experimentally and confirmed by numerical simulation that strong local stretching of sensing fibre distorts the signal detected by a phase-sensitive optical time-domain reflectometer (OTDR) from the fibre section behind the local disturbance region. Comparison of experimental data with theoretical estimates and numerical simulation results leads us to conclude that the physical mechanism underlying the distortion of the OTDR trace is related to the external disturbance-induced variable shift of the optical carrier frequency of probe pulses.

中文翻译：

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传感光纤局部强拉伸对相敏光时域反射仪工作的影响

实验表明并通过数值模拟证实，传感光纤的强烈局部拉伸会使相敏光时域反射仪 (OTDR) 从局部干扰区域后面的光纤部分检测到的信号失真。实验数据与理论估计和数值模拟结果的比较使我们得出结论，OTDR轨迹失真的物理机制与外部干扰引起的探测脉冲光载波频率的可变偏移有关。