基于新型长周期光纤光栅的低成本应变传感系统

首次利用高频CO2激光脉冲写入的长周期光纤光栅的边缘滤波效应，实现了静态与动态应变的测量.使用单波长输入光，光信号经过长周期光纤光栅衰减后进入光电探测器，最终输出电压信号.当对光栅施加应变时，其中心波长将发生漂移，由于光栅阻带的边缘滤波效应，光电探测器接收的光强会随之变化，测量其输出的电信号，可以得出光栅发生的应变大小与频率.对于静态应变测量，可分辨的最小应变小于10 με，精度为±10 με;在动态实验中,发现光栅能够响应5 kHz以上的动态应变.这种传感系统结构简单，成本低,响应快.

A Strain Sensing System Based on the Novel Long-period Fiber Grating

Based on the effect of edge-filter, it is for the first time that a novel long-period fiber grating is used as sensor to measure static and dynamic strain. The input signal from a light source of single wavelength is attenuated by the long-period fiber grating, and then received by a photodetector. The loss band of the LPFG will shift in the direction to shorter wavelength when the grating is strained. Due to the effect of edge-filter, the light intensity received by the photodetector will change in response. As a result, the electrical output of the photodetector can be used to reflect the strain forced on the grating. In the static measurement, the result shows that the relation between the electrical output of the sensor and the strain forms a conic. The resolution of this sensing system is better than 10 με, and the error is about ±10 με. This system can response dynamic strain over 5 kHz too. This sensor system is low-cost and fast.