A new structure of accelerometer based on long period fiber grating (LPFG) was proposed and demonstrated by experiment. As the LPFG is glued to the top of the cantilever, the micro-bending phenomena caused by the outside force is transformed into the variation of the fiber curvature, and the variation of grating transmission and resonance wavelength can be monitored. The fiber Bragg grating (FBG) is used to record the variation of the long period grating transmission in the fixed wavelength condition using its reflective characteristic. Then, it is transformed into the acceleration. The experimental data shows that the sensitivity and comparability of the system are 0. 85dBm/g and 0.99091 respectively. The use of FBG optimizes the system and makes the sensitivity tunable.%提出了一种基于长周期光纤光栅(LPFG)弯曲特性的加速度传感方法.传感系统采用悬臂梁结构,LPFG粘贴于悬臂梁的上表面,将悬臂梁的自由端受力产生的梁体弯曲转变成长周期曲率的变化,来监测光栅谐振谱的幅值和波长变化.并在系统中加入布拉格光栅(FBG),利用其反射特性记录固定波长处长周期光栅谐振谱的变化,然后将其转化为加速度值.实验测得系统灵敏度为0.85dBm/g,系统线性度良好且线性拟合度达0.99091,布拉格光栅对系统的优化作用明显,使得系统灵敏度获得较大提高并实现灵敏度可调.
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