Miniature vibration sensor based on a compact microfiber probe

A miniature vibration sensor based on a compact microfiber probe is proposed and experimentally demonstrated. The microfiber probe is simply fabricated by snapping a multimode biconical microfiber in the fused tapering process. Vibration causes periodic bending and axial extension of microfiber probe, resulting in the change of phase difference between fundamental mode and high-order modes. The vibration signal can be obtained by demodulated the reflected light signal with fast Fourier transform. The experimental result shows that the vibration sensor not only can exactly measure the frequency of the applied sinusoidal vibration signal, but also has a wide frequency measurement range of 20 Hz-2 kHz. The advantages of compact size and high accuracy make the vibration sensor have great application prospects.