Multiplexing of fiber Bragg grating sensors using a FMCW technique

We report on the use of a frequency-domain reflectometry technique for multiplexing fiber Bragg grating (FBG) sensors. This technique is based on the modulation of light intensity 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.