Recent Advances in Multidimensional Fiber Bragg Grating Accelerometers

Fiber Bragg grating (FBG) accelerometers measure vibrations by demodulating wavelength shifts induced by dynamic strain. Their high-temperature resistance and multiplexing capabilities provide them with opportunities for quasi-distributed applications in harsh environments. The basic principle of an FBG accelerometer is based on vibration-strain coupling. In the design of a sensor's mechanical structure, improving the coupling efficiency can effectively enhance the sensitivity of the accelerometer. Moreover, an FBG accelerometer can be developed as a multidimensional sensor, which is a unique feature compared to distributed-fiber vibration-sensing technology. In this paper, we review the recent advances in FBG accelerometer developments and by focusing on two main trends: sensitivity enhancement and orientation identification. We emphatically introduce new techniques for FBG accelerometers including hybrid strain loading, thin-cladding fiber FBGs, multicore FBGs and cladding FBGs.