We present a new technique for fiber Bragg grating (FBG) sensor interrogation and multiplexing. The technique combines a scanning bandpass filter used to multiplex by wavelength multiple gratings in a single fiber,and an unbalanced Mach-Zehnder fiber interferometer made with a 3 3 coupler to detect strain-induced wavelength shifts. A demonstration system interrogates four gratings in a single fiber at a sampling rate up to 20 kHz, with a noise floor measured at less than 10 n/Hz above 0.1 Hz.
Gregg A. Johnson, Michael D. Todd, Bryan L. Althouse, and C. C. Chang, "Fiber Bragg Grating Interrogation and Multiplexing with a 3 3 Coupler and a Scanning Filter," J. Lightwave Technol. 18, 1101- (2000)