基于温控Bragg光栅滤波器的光纤Bragg光栅动态应变传感系统

描述了一种基于温控光纤光栅解调的光纤光栅动态高精度应力测量系统.传感光纤光栅的Bragg反射光受到动态应力调制,反射光其后入射到温控光纤光栅滤波器,传感系统通过测量温控光纤光栅的透射光强变化实现了动态应力解调.温控调节温控光纤光栅,使传感系统始终处于透射光强对应力变化最敏感的最佳状态.利用光纤光栅滤波器的大斜率特性,实现了高动态精度的动态应力传感.以简支梁的自由振动作为研究对象,在有效探测简支梁带宽为1～3 200 Hz的谐振频率范围内获得了高达6.7×10-10ε/Hz1/2的动态应力测量精度.

Dynamic Strain Fiber Bragg Grating Sensor System Based on Temperature Controlled Fiber Bragg Grating Filter

The paper presents a high dynamic strain resolution fiber Bragg grating (FBG) sensor system based on temperature controlled fiber Bragg grating demodulation. The reflected light from sensor FBG is modulated by the dynamic strain, and is filtered by temperature controlled FBG. The sensor system measures the transmitted light power and demodulates the dynamic strain. The sensor system is ensured at the best measurement condition with the modulated temperature controlled FBG. And the high dynamic resolution is achieved with the high rate of filter slope of Temperature controlled FBG. The natural vibration of the free beam is researched by the sensor system. The resonant vibration frequency in bandwidth of 1~3200Hz is measured effectively, and the dynamic strain resolution reaches as high as 6.7×10-10?/Hz1/2.