Finite Element Analysis of a Fiber Bragg Grating Accelerometer for Performance Optimization

N. Basumallick[1], A. Ghosh[1], P. Biswas[1], K. Dasgupta[1], S. Bandyopadhyay[1]
[1]Fiber Optics Laboratory, Central Glass and Ceramic Research Institute, Kolkata, West Bengal, India
Published in 2012

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. Use of finite element analysis 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. Using this optimum design, a sensitivity ~ 1062 pm/g has been experimentally achieved, the enhancement almost by a factor of three as compared to that of the conventional cantilever-mass FBG accelerometer of similar bandwidth.