A Fiber Bragg Grating Accelerometer Based on a Hybridization of Cantilever Beam

A compact fiber Bragg grating (FBG) accelerometer based on a hybridization of two cantilever beams is demonstrated. Two FBGs are prestressed and fixed on the combined-beam longitudinal symmetrically. When a vibration is exerted on the accelerometer, the reflection-peaks of two gratings shift sharply in opposite directions without unwanted chirp. Experimental results show that the proposed sensor exhibits a high dynamic sensitivity of 218.4 pm/G and broad frequency range of 10-150 Hz with a wide dynamic range of 0.1 to 3 G. The cross-axis response is 3.2% of the main axis, and the temperature is self-compensated owing to the same responses to temperature of two reflection wavelengths.