Axial strain applied in-fiber Mach-Zehnder interferometer for acceleration measurement

We present an axial strain applied in-fiber Mach-Zehnder interferometer (MZI) for acceleration measurement. A thin core fiber is sandwiched between two single-mode fibers with core offset to form the MZI. A controlled high fringe visibility in the transmission spectrum is obtained by applying an axial strain, leading to a large slope at the quadrature point. The MZI is then clamped to work as an accelerometer. Experimental results show that the resolution achieves 86 ng/√Hz (g is gravity of 9.8 m/s²), the dynamic range reaches as large as 104.1 dB and the linearity of acceleration response is as high as 99.994%. Moreover, the resonance frequency can be tailored by the clamped fiber length and applied axial strain. The proposed sensor is attractive for practical applications due to low temperature crosstalk, compact size and high sensitivity.