设计了一种基于可调谐滤波器的高精度宽量程光纤布拉格光栅(FBG)传感解调系统,通过动态跟踪与锁定的方法将法布里珀罗可调谐滤波器(FFP-TF)的输出激光锁定在传感光栅反射谱的-3 dB处,利用对温度不敏感的标准具对光栅反射波长进行校准,再通过插值拟合算法实现传感光栅中心波长的实时高精度解调。该解调系统解决了基于光学滤波器光栅解调系统所存在的精度与测量范围之间相互制约的矛盾。实验结果表明系统的静态波长漂移量在较宽的测量范围内为2 pm,多项式拟合精度达0.998。
A high precision and wide scale fiber Bragg grating (FBG) sensor interrogation system based on fiber Fabry-Perot tunable filter (FFP-TF) is demonstrated. By dynamic tracking and locking of the driving voltage of FFP-TF, the output wavelength of the laser is locked at the -3 dB reflectivity spectrum of the FBG. A temperature immune Fabry-Perot international telecommunication union filter is used as the reference channel. The interpolation algorithm is then used to realize high precision interrogation of dynamic strain. This design resolves the conflict between resolution and measurement scale in interrogation system based on optical filter. A high resolution better than 2 pm within wide strain measurement range is verified by experiments. The polynomial result of FBG spectrum is 0.998.