基于多频相位生成载波的光纤振动传感技术研究

Research on Optical Fiber Vibration Sensing Technology Based on Multi-Frequency Phase-Generated Carrier

为了满足周界安防区域数目扩增的需求,提出了一种基于多频相位生成载波的光纤振动传感技术,利用多个相位调制器实现了不同振动信号的频谱搬移,采用微分交叉相乘算法开展了多路干涉信号的相位解调,进行了相位生成载波调制深度的选值分析,并搭建了基于直线型萨格奈克干涉原理的多通道光纤振动传感实验系统。实验结果表明,干涉信号频谱含有多频载波成分与频谱搬移的边带成分,经解调可获得准确的振动信号,其频谱信噪比平均为27.3 dB,谐波失真度平均为8.22%,并在模拟应用场景中对人为敲击信号进行了准确解调,从而为本系统在交通领域的多防区周界安防应用提供了参考。

An optical fiber vibration sensing technology based on multi-frequency phase-generated carrier is proposed.Multiple phase modulators are used to realize the spectrum shifting of different vibration signals.The differential cross multiplication algorithm is used to carry out the phase demodulation of multi-channel interference signals,and the value selection analysis of the modulation depth of phase-generated carrier is carried out.A multi-channel optical fiber vibration sensing system based on linear Sagnac interference principle is built.The experimental results show that the spectrum of interference signal contains multi-frequency carrier component and side band component of spectrum shifting.Accurate vibration signal can be obtained by demodulation,the average SNR of spectrum is 27.3 dB and the average harmonic distortion is 8.22%.The accurate demodulation of artificial knocking signal is carried out in the simulation application scenarios.It provides a reference for the application of the system in the perimeter security of multi-defense area in traffic field.