提出了一种基于π相位温度不敏感的双光纤布拉格光栅加速度传感技术,并设计了双光栅加速度传感器,对该传感器的温度特性和加速度对中心波长的响应进行了研究。给出了该传感器的结构及封装方法。从理论上分析了基于π相位温度不敏感的双光纤布拉格光栅加速度传感原理,分析了温度和加速度对波长的响应关系,推导了该光栅加速度传感器的响应灵敏度的解析表达式。通过实验分析双光栅的加速度响应和平坦区。实验结果表明,在温度比较宽的范围内,可实现温度不敏感加速度的准确测量,加速度响应灵敏度为15.52 pm/(m.s-2),实验值与理论值的相对误差为3.06%,加速度与波长具有较好的线性关系,线性度为99.8%,在小于共振频率的低频段具有较好的平坦区。表明该双光纤布拉格光栅加速度传感器具有温度不敏感特性,能实现低频加速度的准确测量。
A novel temperature-independent technology based on π phase of double fiber Bragg grating(FBG) acceleration is proposed.The double fiber Bragg grating accelerometer is designed.The temperature response and acceleration response of the sensor versus wavelength are researched.The configuration and coating of the accelerometer are designed.The temperature-independent principle based on π phase of double fiber Bragg grating accelerometer is analyzed.The temperature response of FBGs and the acceleration response versus wavelength are analyzed.And the analytical formula of acceleration sensitivity is also deduced.Acceleration response and flat range of the accelerometer are analyzed by experiment.Experimental results indicate that precise measurement can be realized in the large range of temperature,and the sensitivity is 15.52 pm/(m·s-2),relative error is 3.06%.The sensor demonstrates extremely linear response,and linear fitting is 99.8%.There is a good flat response at frequencies less than the mechanical resonance frequency,which indicates that the accelerometer has good temperature-independent characteristic and can realize precise measurement.