High-Speed FBG-Based Fiber Sensor Networks for Semidistributed Strain Measurements

Conventional fiber-Bragg-grating (FBG)-based sensor networks based on either wavelength- or time-division-multiplexing (WDM or TDM) schemes may suffer from low interrogation speed with moving mechanical parts or inevitable crosstalk between nodes with the same Bragg wavelength. In this paper, by incorporating both TDM and WDM schemes into matched FBG-based sensor networks and facilitated by the high-speed electronic platform, we achieve 400-kHz sampling speed for each sensor node with a 5-meter spatial resolution. Semidistributed strain measurement is demonstrated on a turbine blade model with results comparable to those by accurate spectral analyses.