Robust 3-Component Optical Fiber Accelerometer For Seismic Monitoring

A robust cantilever-based push pull 3-component (3-C) optical fiber accelerometer is proposed and experimentally demonstrated. Sensitivity and resonance frequency can be enhanced simultaneously by increasing the number of turns of an optical fiber without increasing the accelerometer size at the mass of a certain value. The calibration results show that axis sensitivity is 45 dB (re: 0 dB = 1 rad/g), with a fluctuation less than 0.9 dB in a frequency bandwidth of 10-450 Hz. The cross sensitivity is approximately 15 dB, with a fluctuation less than 1.2 dB in a frequency bandwidth of 10-450 Hz. The crosstalk reaches up to 30 dB. Fluctuation of the responses of the acceleration sensitivity of different components is less than 0.7 dB over a frequency bandwidth of 10 -450 Hz, which proves the good consistency of the 3-C optical fiber accelerometer. By usingan all-metal structure is expected to improve the reliability of the designed accelerometer for long-term use in harsh environments. These desirable features show that the proposed 3-C optical fiber accelerometer is satisfactory for seismic wave monitoringin oil and gas exploration.