Low-frequency fiber Bragg grating accelerometer based on a double-semicircle cantilever

A compact double fiber Bragg gratings (FBGs) accelerometer based on an organic double-semicircle cantilever is proposed and experimentally demonstrated for low-frequency vibration measurement. The configuration is formed by two points of every FBG fixed at the two sides of the semicircle, efficiently avoiding the unwanted chirp effect of grating. The dynamic vibration measurements exhibit that the accelerometer provides an extremely high sensitivity of 1296 pm/g and a considered frequency range from 0 to 25 Hz, while the two FBGs is contributed to the sensitivity enhancement, temperature and transverse sensitivity independent. The smart device has a compact size and efficient fabricating cost, indentifying it a good candidate for the embedding structure monitoring.