基于相位敏感光时域反射计的音频激励信号解调与复现

Demodulation and reproduction of audio excitation signals based on Φ-OTDR

解调复现外部振动信号在实际工程监测应用中具有广阔的应用前景。基于相位敏感光时域反射计(Φ-OTDR)的DAS可以探测分布式单模光纤的振动信号,其集传感和光纤于一体且还原原始信号时无需参考信号,适用于工程应用。本文设计演示了一种基于Φ-OTDR的直接监测的简易且低成本的音频振动信号的解调与复现系统。在实验装置中使用聚苯乙烯板作为声音在空气中传输的增敏材料。将正弦干扰声音、人声及音乐三种激励源通过扬声器对待测光纤播放,证明本系统能在10 km的传输距离中复现频率丰富的外部振动信号,且具有4 m的空间分辨率,该系统适用于长距离监测下的外部振动的解调复现。

Demodulation and reproduction of external vibration signals has broad application prospects in practical engineering monitoring applications.The DAS based on the can detect the vibration signal of the distributed single-mode fiber.It integrates the sensing and the optical fiber and restores the original signal without reference signal,which is suitable for engineering applications.This paper demonstrates a simple and low-cost demodulation and reproduction system for audio vibration signals based on direct monitoring.Polystyrene plates were used in the experimental setting as sensitizing materials for the transmission of sound into the air.Sinusoidal interference sound,human voice and music are played through the speaker to test the optical fiber,which proves that the system can reproduce the external vibration signal with rich frequency over a transmission distance of 10 km and has a spatial resolution of 4 m.The system is suitable for demodulation and recurrence of external vibrations under long-distance monitoring.