Cantilever Fiber-Optic Accelerometer Based on Modal Interferometer

A cantilever fiber-optic accelerometer using modal interferometer, with a large fringe visibility of up to 30 dB, is proposed and demonstrated. In the system, an electrical testing replaces optical-spectrum detection to achieve fast acceleration measurement of the cantilever fiber-optic accelerometer, and the performance of the cantilever fiber-optic accelerometer is studied experimentally. Experimental results show that the minimum detectable acceleration is 1.36 mg, and the resonance frequency is 520 Hz. Meanwhile, the angular dependence of the fiber accelerometer is also analyzed in the article and the result shows that the output intensity difference is up to 18 dB for different angles. This fiber-optic accelerometer can be used to detect underwater acoustic and seismic wave.