Toward sensitivity-enhanced fiber-optic vibration measurement through deflection amplification structure

Vibration signal detection has been applied in various fields of industrial control, gas sensing, medical diagnosis, earthquake monitoring and so on. Especially in the field of vibro-acoustic analysis, high-sensitivity monitoring method is crucial for weak signal detection. Here we introduce a series of sensitivity-enhanced fiber-optic vibration sensors. 1) An extrinsic Fabry-Perot interferometric (EFPI) acoustic sensor is reported, which is constructed by an in-fiber collimator, adjustable 45° mirror and a cantilever. 2) An EFPI based acceleration sensor is proposed. Based on a novel lever and buckled beam structure, deflection is highly amplified, which is further monitored through EFPI structure. Both proposed sensors realize sensitivity enhancement up to ten times. With high sensing performance, low-cost and enhanced robustness, the proposed sensors make them promising candidate for vibration monitoring.