An intensity-based interrogation technique for arrays of fiber bragg grating(FBG) sensors is reported. The technique is based upon each FBG forming onemirror of a Michelson interferometer. Source wavelength modulation is combinedwith an unbalanced interferometer to produce a carrier signal. Carrierfrequencies are characteristic of the optical path length imbalance and hencegrating position within the array. The intensity of the carrier signal isdirectly related to the optical power reflected from the grating and hence thestrain applied to the grating. Strain resolution of ∼3μm/m is demonstrated withan ∼350μm/m sensor range. Multiplexing is demonstrated and techniques to extendthe range are disc
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