布拉格光纤光栅传感器在非均匀应变场中的响应分析

Analysis of response of optical fiber Bragg grating sensors in non-homogeneous strain fields

在非均匀应变场的作用下,布拉格光纤光栅的主要参数有效折射率和光栅周期都会发生非均匀的变化,导致光纤光栅的反射光光谱结构发生变化。在光波导耦合模理论的基础上,建立了布拉格光纤光栅在非均匀应变场下反射光谱的分析数学模型,利用龙格 库塔法对其进行了数值求解。给出了几种典型应变场下的布拉格光纤光栅的反射光谱,并分析了它们的特点。

When optical fiber bragg grating (FBG) sensors are subject to nonhomogeneous strain, the response of FBG reflective spectrum is due to nonhomogeneous variation of both the fiber core index and the grating pitch. Based on couplemodes equations, the mathematical model of the response of FBG reflective spectrum in nonhomogeneous strain fields is established, and RungeKutta numerical method is utilized to gain numerical result. The response of FBG reflective spectrum in some typical nonhomogeneous strain fields is showed, and their characters are analyzed.