基于副载波调频技术的光纤光栅传感网络查询

分析了副载波调频技术用于光纤光栅阵列查询的基本原理。从理论上推算了系统的查询空间分辨率及查询范围,并结合波分复用技术进行了光纤光栅传感网络的地址查询演示实验,同时使用可调谐滤波器对每个光栅信号进行了解调。实验结果很好地说明了该查询方案的可行性,且在单个光栅上的被测应变与可调谐滤波器的控制电压呈较好的线性关系。该系统具备有查询由几百个FBG组成的传感网络的潜在能力。

Fiber Bragg grating array interrogation with sub-carrier frequency modulation technique

The fundamental principle of sub-carrier frequency modulation used for FBG array interrogation is analyzed. The space resolution and interrogation range of this system are calculated theoretically. Then a sensor network of FBG array is experimentally demonstrated combined with wavelength division multiplexing and every FBG signal is demodulated by using tunable optical filter. Experimental results indicate that this interrogation method is feasible and the strain applied on single grating is linear with the control voltage of tunable optical filter. This system has the potentialities of interrogating and demodulating sensor network consisting of several hundreds FBG sensors. So it has good prospects in monitoring two or three-dimensional distribution strain of large constructions.