Low-Frequency Vibration Sensor with Dual-Fiber Fabry–Perot Interferometer Using a Low-Coherence LED

In this paper, we propose a dual-fiberoptic Fabry–Perot interferometer (FFPI) sensing system integrated with low-cost and low-coherence light-emitting diode (LED) as light source to detect dynamic vibration caused by acoustic waves cut-off frequency of 200 Hz. When the signals are applied, FFPI on Styrofoam sheet provides function partially transforming longitudinal energy transverse generates phase shift in cavity. The reflected from sensor is demodulated reference extract measurand. low-power (sub-nW) optical transferred into electrical signals, processed designed receiver, recorded for data analysis.