We present a high-resolution simultaneous strain and temperature measurement scheme using ${\pi }$-phase-shifted fiber Bragg grating written in PANDA-type polarization maintaining fiber. Two optical parameters, the Bragg frequency and the… Click to show full abstract
We present a high-resolution simultaneous strain and temperature measurement scheme using ${\pi }$-phase-shifted fiber Bragg grating written in PANDA-type polarization maintaining fiber. Two optical parameters, the Bragg frequency and the birefringence-introduced frequency difference, are measured to perform the discrimination of strain and temperature. A double-sideband interrogation method together with a cross-feedback technique is introduced, which significantly reduces the measurement error in birefringence-introduced frequency difference, and hence improves the sensing resolution of strain and temperature. In the demonstration experiment, simultaneous measurement of strain and temperature with resolutions of 0.018 $\mu$ ${\epsilon }$ and 0.0014 $\boldsymbol {^{\circ }}$C respectively is realized.
