研究了一种用光纤光栅测量动态应变的阵列传感技术。在用基于3×3耦合器的非平衡光纤马赫-曾德尔干涉仪解调光纤光栅波长变化基础上,提出了通过波分复用器(WDM)来实现多个光纤光栅振动传感器的复用,测试了波分复用器对通道交叉干扰的影响,并同时测得了串联的3只光纤光栅的振动信号。讨论了使用这一技术时,工作环境和光源光强的变化对测量没有显著影响以及该技术可以用于高频信号的测量原因。该技术优点在于测量频率高、灵敏度高,不受光源光强度的影响,还可以获得不同测量点之间的相位关系。

An array sensing technique of fiber grating for the dynamic strain measurement is demonstrated in this paper. The technique is based on unbalanced Mach-Zehnder interferometer which use a 3×3 coupler. Wavelength division multiplex (WDM) technique is introduced to multiplex fiber grating sensors. The cross talk among the different channels is measured, and vibration signals from 3 serious FBGs is obtained at same time. The reasons why the changes of environment and changes of power intensity do not influence the measurement are discussed. And signals with high frequency can also be measured. Not only high-frequency, high-sensitivity measurement can be achieved, and the measurement is not affected by power intensity, but also the phase relationships among the different sensing position can be obtained.