White-light-driven resonant fiber-optic strain sensor.

Recently, laser-driven resonant fiber-optic sensors (FOSs) have been reported to reach the ultimate resolution limit, set by the thermal noise in fiber. However, they are still far away from commercialization because of their dependence on expensive and ultra-narrow-linewidth lasers. In this Letter, a white-light-driven resonant FOS is proposed for the first time, to the best of our knowledge. By using the white-light multi-beam interferometry, the resonant peaks of a fiber Fabry-Perot interferometer sensor are obtained, and the resonance drifts are tracked for sensor readout by using the Pound-Drever-Hall technique. The proposed FOS is adopted for strain measurement, and the achieved strain resolution (0.9ε/√ at 100 Hz) is comparable with that of laser-driven FOSs.