Design and Validation of a Novel High Sensitivity Self-Temperature Compensated Fiber Bragg Grating Accelerometer

Abstract

Fiber Bragg Grating-based accelerometers are being used in structural health monitoring as they offer several advantages over their electrical counterparts. In this paper, the concept of a novel T-shaped cantilever-based mechanical sensor head is proposed on which the two Fiber Bragg Gratings are integrated in a differential sensing configuration to realize an optical accelerometer. This elegant design simultaneously achieves the dual goals of sensitivity enhancement, and self-temperature compensation. A mathematical model of the accelerometer is developed, and numerical simulations are carried out for three mechanical sensor head designs. A prototype is fabricated and characterized to prove the design. The sensitivity of 821 pm/g of is achieved with a linearity of 99.7%, cross-axis sensitivity of 0.3%, and natural frequency of 64 Hz; self-temperature compensation is achieved with an error of 0.07 pm/°C.