Multicore Fiber Based Phase-Modulation Interferometer for Demodulation of a Fiber Bragg Grating Accelerometer

In this article, we propose a phase-modulation interferometer based on Multicore fiber for demodulation of a fiber Bragg grating (FBG) accelerometer using a multicore fiber (MCF) interferometer. The MCF interferometer are made by using two parallel spatial cores of the MCF. A Michelson interference can be generated by reflected light from two independent cores of a winding MCF. We experimentally demonstrate that the vabriation signal demodulation of a felxible hinge FBG accelerometer using the proposed MCF interferometer system. The experiment results show that the phase demodulation scheme of the FBG accelerometer based on MCF interferometer proposed in this article can demodulate the acceleration with a sensitivity of 2.3 +/- 0.3 rd/g at a frequency band of 20-130 Hz. The usage of the MCF interferometer enhance the integration of the phase demodulation system of the FBG sensors and also show potentials in other optical interferometry and sensing applications.