FBG滤波的级联LPFG温度和折射率传感装置

Cascaded LPFG Temperature and Refractive Index Sensing Method Based on FBG Filter

利用长周期光纤光栅具有较高的温度、折射率灵敏度,以及光纤布喇格光栅具有较高反射效率的特点,设计了一种基于光纤布啦格光栅滤波的级联长周期光纤光栅温度和折射率传感装置.利用光纤布喇格光栅的高反射率,将级联长周期光纤光栅干涉波峰的局部功率反射到功率计中,实现了温度和折射率的测量.基于信号叠加原理,对光纤布喇格光栅滤波的级联长周期光纤光栅温度和折射率传感方法的可行性进行了分析.将实际测得的功率计示数与温度以及折射率的变化进行二项式拟合,其确定系数分别为0.9990和0.9959,表明该传感方法可用于温度和折射率的精确测量.最后对该装置的稳定性做了一系列的测试,验证了该传感系统具有较高的稳定性.

Based on the high temperature and refractive index sensitivity of long period fiber gratings （LPFGs） and the high reflection efficiency of the fiber Bragg grating （FBG） filters, a temperature and refractive index sensor was designed, which is a cascaded LPFG based on the FBG filter. The temperature and refractive index were measured by using the FBG filter to reflect partial power of interference wave of the cascaded LPFG into the power meter. In this paper, the feasibility of the cascaded LPFG based on FBG filter temperature and refractive index sensor was analyzed by the signal superposition principle. Then, the binomial fitting was done between the power meter readings and changes of the temperature, and the power meter readings and refractive index. The determination coefficients are 0. 9990 and 0. 9959 respectively. The high stability of the proposed sensor was also tested. These results show that the cascaded LPFG based on FBG filter temperature and refractive index sensor could be used for the precise measurement of the temperature and refractive index and has a high stability.