可调激光边沿滤波解调光纤光栅实时应变测量

Real-time Strain Measurement of Fiber Bragg Grating Based on Edge Filter Demodulation Using Tunable Laser

提出了利用波长可调谐激光器对光纤光栅进行边沿滤波解调的新方法,该方法可实现多个测点动态应变的实时监测。实验将多个“贴片式”光纤Bragg光栅应变传感器固定在武汉长江二桥箱形梁的选定点上,这些应变传感器通过光缆串联并接回监控室,在监控室内使用可调谐半导体激光器做光源,利用边沿滤波解调原理,对多个测点的动态应变进行实时测量,得到这些测点的动态应变波形,取得了很好的实验结果。该解调方法适合于进行多点的实时应变测量,克服了边沿滤波解调只能进行单点测量的缺点。

A novel method of edge filter demodulation for fiber Bragg grating that use wavelength tunable laser was proposed. Real-time monitoring of the multiple points＇ dynamic strain could be achieved. Several patch FBG strain sensors were installed on the box girders of the second Wuhan Yangtze River Bridge and connected to the control office by optical cable. Based on edge filter demodulation, tunable LD as the light source, the real-time measurement of the multiple points＇ dynamic strain was carried out, and the experimental results of dynamic strain wave were well obtained. The method was superior to the other edge filter demodulation methods, because it was available for the multi-points measurements of real-time strain.