Research on Theoretical Model of High Sensitivity Fiber Bragg Grating Accelerometer

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