基于扫描光纤激光器的光纤传感解调仪研究

Swept Fiber Laser Based Fiber Optic Sensor Demodulator

介绍了一种基于扫描光纤激光器的光纤传感解调系统.采用氰化氢(HCN)气体吸收池作为波长参考基准,采用三次多项式拟合的方法来确定光纤F-P可调谐滤波器的波长与驱动电压的对应关系,可调谐滤波器扫描过程中对扫描电压、多路光谱信号进行同步采样,实时标定.实验结果表明,该解调系统在1510nm到1590nm波长范围内对FBG反射峰值波长的分辨率为1.4pm,长期波长重复性达到3.2pm.利用该系统实现了对FBG反射峰值波长和光纤EFPI传感器腔长的高准确度解调.

A fiber optic sensing demodulation system based on a swept fiber laser was reported. A HCN gas cell was adopted as an embedded wavelength calibrator for the swept laser. The relation between the scanning voltage applied to the fiber Fabry-Perot tunable filter （FF-PTF） and the lasing wavelength was given out by a three order nonlinear fitting. The scanning voltage and multi-channel spectroscopy signal from sensors were sampled simultaneously and calibrated in real time. The interrogation wavelength resolution of 1.4pm and the long term repeatability of 3.2 pm were achieved. Demodulation test results for FBG and F-P sensors show that the system is capable of measuring the reflected peak wavelength of FBG and cavity length of fiber EFPI sensor with high accuracy.