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IEEE Journal of Lightwave Technology
Volume 18 Number 8, August 2000

Fiber Bragg Grating Interrogation and Multiplexing with a 3 × 3 Coupler and a Scanning Filter

Page 1101.

Abstract:

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/ above 0.1 Hz.

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