A New Fiber-Bragg-Grating Sensor Interrogation System Deploying Free-Spectral-Range-Matching Scheme With High Precision and Fast Detection Rate

A new method for fiber-Bragg-grating sensor interrogation and multiplexing is proposed and its operating features are investigated experimentally. This technique utilizes free-spectral-range-matched interrogation (FSRMI) employing a tunable scanning Fabry-Perot filter and a multichannel bandpass filter. An -channel FSRMI allows simultaneous scanning and thus improvement of detection speed by times compared to a nonfree-spectral-range-matched interrogation scheme. A 5-pm wavelength resolution has been obtained. This technique simultaneously scans the multiple transmission peaks and provides solutions to a wavelength-modulated distributed sensors and multisensor arrays with high sampling speed and wavelength accuracy.