In-line fiber microcantilever vibration sensor

We demonstrate a fiber-based vibration sensor that involves an enclosed suspended microcantilever integrated with a readout fiber, providing in-line measurement of frequency and amplitude of vibration. The microcantilever is fabricated from a bend-insensitive fiber by chemical etching and fused to a single-mode fiber. Vibration induced periodic bending of the microcantilever angularly scans the readout fiber core resulting in output power modulation corresponding to certain drive frequencies and voltages of a shaker. Experimental results agree well with the theoretical analysis and demonstrate a continuous vibration frequency range of 5 Hz–10 kHz with a maximum signal-to-noise ratio of 68 dB.