title: Linear FBG Temperature Sensor Interrogation with Fabry-Perot ITU Multi-wavelength Reference.
abstract: The equidistantly spaced multi-passbands of a Fabry-Perot ITU filter are used as an efficient multi-wavelength reference for fiber Bragg grating sensor demodulation. To compensate for the nonlinear wavelength tuning effect in the FBG sensor demodulator, a polynomial fitting algorithm was applied to the temporal peaks of the wavelength-scanned ITU filter. The fitted wavelength values are assigned to the peak locations of the FBG sensor reflections, obtaining constant accuracy, regardless of the wavelength scan range and frequency. A linearity error of about 0.18% against a reference thermocouple thermometer was obtained with the suggested method.
authors.affiliation: Division of Electronics and Information Engineering, Chonbuk National University, Jeonju 561-756, Korea. spacegon@chonbuk.ac.kr.
authors.forename: Hyoung-Jun
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Division of Electronics and Information Engineering, Chonbuk National University, Jeonju 561-756, Korea. msong@chonbuk.ac.kr.
authors.forename: Minho
authors.initials: M
authors.lastname: Song
keywords: Fabry-Perot filter; Fiber Bragg grating; Fiber-optic temperature sensor