Overcoming the trade-off between the static sensitivity and resonant frequency of an FBG accelerometer

Abstract

Although the method to overcome the tradeoff between the static sensitivity and resonant frequency of an FBG (fiber Bragg grating) accelerometer was reported, by narrowing the distance between the two fixed ends of the FBG, an explicit mathematical explanation has never been revealed until now. Besides the revelation, a novel mechanical structure is also proposed to effectively shorten the distance by moving the inertial object below the two fixed ends and hanging it on the FBG to apply forces. The crest-to-trough sensitivity 1.79 nm/g at 5 Hz and the resonant frequency 90 Hz are experimentally demonstrated.