Multiplexing of fiber Bragg grating sensors using an FMCW technique

Abstract—We report on the use of a frequency-domain reflec-tometry technique for multiplexing fiber Bragg grating (FBG) sensors. This technique is based on the modulation of light inten-sity from a broadband source by a swept-frequency RF carrier. Signals from the FBG sensors located at different positions in an array are separated in the frequency-domain and demodulated using a tunable optical filter. A three FBG sensor system is experimentally demonstrated. The potential of the technique for multiplexing a large number of FBG sensors is discussed. Index Terms—Fiber Bragg gratings, frequency division multi-plexing, optical fiber sensors