Study of Temperature Decoupling Fiber Acceleration Sensor Based on the Dual-FP Structure

Abstract

There is seriously temperature coupling affection in the traditional fiber acceleration sensor, which affects the measurement accuracy. In order to improve anti-interference ability of the sensor, the structural characteristics of the dual-FP cavity is adapted to realize temperature decoupling. Based on the double-beam interference theory, the optimal film thickness requirements, and the output spectrum change of FP cavity caused by the vibration and temperature change is analyzed. Acceleration sensor with structure of the dual-FP cavity and three-bridge is designed. The structure of sensor is analyzed by ANSYS software, such as the thickness of the bridges and the mass size of sensor, and cavity length change caused by equivalent force. Based on the analysis, it can be concluded that the corresponding bridge thickness is 100μm and mass diameter is 0.5mm for the sensor with external diameter of 2 mm and inner diameter of 1.6mm. The resonant frequency of the system is 6.6kHz, and measuring range is 0 ~ 10g.