Design Development and Validation of High Performance Fiber Bragg Grating Accelerometers

Abstract

Fiber Bragg grating (FBG) accelerometers have attracted the attention of researchers as an efficient and attractive alternative to conventional electrical accelerometers. They exploit the remarkable sensing capabilities of the FBG in combination with varieties of novel mechanical sensor heads. The FBG is an intrinsic optical sensor, which provides the measurand information in the wavelength-encoded format. The FBG accelerometers are light, compact, less noisy, highly sensitive, immune to electromagnetic interference, capable of sensing efficiently in harsh environments, and fit to carry out distributed sensing. These unique and promising characteristics have generated a lot of interest in exploring the use of FBG accelerometers in various fields of science and technology. Though various types of FBG accelerometers are proposed by different researchers to achieve specific characteristics, there is a need to realize high-performance FBG accelerometers, which have high in-axis sensitivity, low cross-axis sensitivity, self-temperature compensation capability, high linearity, reasonably good bandwidth, and wide dynamic range. To achieve the above objectives, three novel configurations i.e. Modular Double-L Cantilever, Monolithic T-Cantilever and Composite Triangular Cantilever based FBG accelerometers are evolved. Mathematical models and designs are analyzed through numerical simulations using MATLAB and finite element method (FEM) simulations using ANSYS. Precise fabrication sequences are adopted for realizing the mechanical sensors heads (MSH) and the FBGs. The FBGs are carefully integrated with the MSHs in optical differential sensing configuration to realize the novel FBG accelerometer prototypes. The accelerometers are characterized for their static, dynamic, and temperature characteristics. Close matching of the experimental results with the theoretical predictions proved the concepts and validated the designs...