High sensitivity optical fiber accelerometer based on symmetric hinge structure with dual mass blocks

Abstract

Abstract A symmetrical multi-level flexible hinge and dual mass block structure fiber Bragg grating accelerometer has been designed, which has the characteristics of small amplitude and high sensitivity. According to the working principle of the two-degree-of-freedom vibration system, there are vibration nodes in the double mass block during the vibration process, and the vibration nodes can reduce the amplitude of the system and protect the optical fiber; and the multi-stage flexible hinge can reduce the structural rigidity and improve the sensitivity of the accelerometer. The experimental results show that the vibration signal is in the range of 5–90 Hz, the acceleration is in the range of 0.1–1 G, the sensitivity of the accelerometer is 878.4 pm/G, and the linear fit R 2 = 0.991. Moreover, the mechanical structure of the accelerometer is integrally machined with high mechanical strength to ensure stable operation of the accelerometer. The designed accelerometer can be used for monitoring low-frequency vibrations in fields such as seismic wave exploration and oil and gas field development.