Resolution-increased fiber-optic strain sensor with a large dynamic range driven by white light

Abstract

The white light interferometer is advantageous for wavelength division multiplexing (WDM), but the excessive noise floor limits its application in practicality. In this Letter, we propose a fiber-optic sensor driven by a broadband light source, which uses a fiber-optic Fabry–Perot cavity and a reference interferometer to enhance strain resolution. In the experiment, the strain resolution of a 5.86 m resonant sensor is 18.5 fɛ/Hz at 1.5 kHz, while the maximum detectable signal is over 230 rad at 1 kHz. With low cost, this method provides a new, to the best of our knowledge, solution for WDM sensing arrays with a large dynamic range.