Demodulation of a Fiber Bragg Grating Sensor System Based on a Linear Cavity Multi-wavelength Fiber Laser

摘要

@@ The FBG central wavelength will vary with the change of strain and temperature. The relationship among the wavelength shift Δλ Band value of strain εεand temperature variations ΔT can be expressed as follows: ΔλB=λB[(1-Pc)ε+(ζT+αT)ΔT] (1) Where λB is the initial central wavelength of FBG, e P is an effective photoelastic coefficient (~0.22) of the fiber, ζT and αT are the thermal expansion coefficient (~0.55×10-6) and thermal optic coefficient (~8.6×10-6) of the fiber, respectively3.