Vibration fiber sensors based on SM-NC-SM fiber structure

Abstract

A novel vibration sensor based on the single mode (SM)-no core (NC)-SM fiber structure is proposed and experimentally sensing results demonstrated. By numerical simulation, we use an NC fiber (NCF) as the multimode waveguide structure for the multimode interference (MMI) sensing. Through intensity demodulation, the vibration sensing structure can detect continuous vibration disturbances with the frequencies of ranging from 100 Hz to 29 kHz and the inherent frequency of cantilever slab of 700 Hz. The frequency sensing resolution is 1 Hz in real-time monitoring. The proposed compact structure is easy to fabricate and has low cost.