高灵敏光纤光栅加速度检波器理论模型研究

针对两点封装，建立光纤光栅加速度检波器通用模型，理论推导加速度检波器灵敏度和谐振频率的解析表达式，深入研究加速度灵敏度和谐振频率的影响因素，讨论封装光纤刚度系数与检波器结构刚度系数之比对检波器响应特性的影响，并分析刚度比分别在0~1、0~100范围随着等效质量的增大(0 g~100 g)，加速度灵敏度和谐振频率的制约关系，及在0 Hz~500 Hz(中低频)和0 Hz~1 200 Hz(中高频)范围内灵敏度的变化规律。此外，分别以封装光纤长度为10 mm和60 mm举例分析长度对上述二者的影响，各项仿真中灵敏度均会高达~1 000 pm/G，并引入品质因数的概念。所提理论研究对FBG加速度检波器的设计和综合性能的评价具有重要的指导意义，为器件参数优化提供理论依据。

Research on theoretical model of high sensitivity fiber Bragg grating accelerometer

A general model of fiber Bragg grating (FBG) acceleration detector was established for the two-point package model. The sensitivity and the resonance frequency's analytical expressions of the acceleration detector were deduced theoretically, the influence factors which affecting the sensitivity and resonance frequency were researched deeply, and the acceleration detector's response characteristics were discussed, which would be affected by the ratio, that the package fiber stiffness to the structure stiffness. Based on this, the restrictive relation between theacceleration sensitivity and the resonance frequency with the increasing of the equivalent mass (0~100g) was analyzed, respectively for the stiffness ratio in the range of 0~1 and 0~100. And the resonance frequency's change rules within the scope of 0~500Hz (low-medium frequency) and 0~1200Hz (medium-high frequency) were also studied. Furthermore, the package fibers were chosen 10 mm and 60 mm as the examples to analyze the influence on the above two mentioned, the sensitivity of each simulation could reach up to ~1 000pm/G, and the quality factor was introduced. This study plays a significant role in the design and comprehensive performance evaluation of the acceleration detector, and can provide theoretical references for the optimization of structural parameters.