A fiber Bragg grating accelerometer based on corrugated diaphragm

Abstract

A high frequency fiber Bragg grating (FBG) accelerometer based on corrugated diaphragm has been proposed. The mechanical model is demonstrated. The accelerometer contains four parts, corrugated diaphragm, a FBG, two mass blocks, shell. The corrugated diaphragm is fixed on the shell. The upper and lower parts of the diaphragm center are symmetrically fixed by two mass blocks. The FBG is glued between the bottom of shell and mass blocks through a microhole. The amplitude-frequency and sensitivity of the accelerometer are theoretically analyzed and experimental measured. Experimental results show that the resonant frequency of the accelerometer is 490Hz, the sensor has a broad flat frequency range from 20 Hz to 350 Hz, the sensitivity of the accelerometer is about 50.3 pm/G with a linearity of 0.9997. The cross-sensitivity of the accelerometer is tested and the cross-axis sensitivity is about 8% of the main-axis. The accelerometer has a wide frequency and high sensitivity, which is promising in cross well micro-seismic exploration.