Design optimization of fiber Bragg grating accelerometer for maximum sensitivity

Sensitivity of a cantilever-mass based fiber Bragg grating (FBG) accelerometer can efficiently be tailored by altering the distance between the axis of the FBG sensor to the neutral axis of the cantilever. To accomplish that in general, a backing patch is used to mount the FBG on the cantilever. A numerical method to quantify the influence of the material constant (Young's modulus) of the backing patch and its thickness on the sensitivity is presented in this paper. It is explicitly shown that for a specific patch material there is an optimum thickness for which the sensitivity happens to be the maximum. A good agreement between simulation and experimental results is obtained. Finally, it is demonstrated that a sensitivity ∼1062 pm/g can be achieved, the enhancement almost by a factor of three as compared to that of the conventional cantilever-mass FBG accelerometer of similar bandwidth.

► Sensitivity enhancement of FBG based cantilever-mass architecture using backing patch. ► Detailed finite element analysis to quantify the influence of the backing patch. ► Effect of surface strain on the overall sensitivity enhancement of the accelerometer.