In-Fiber Gratings for Simultaneous Monitoring Temperature and Strain in Ultrahigh Temperature

In this letter, a pair of regenerated gratings with Bragg wavelengths of 1547 and 1304 nm in a single piece of singlemode fiber has been fabricated for simultaneous monitoring of temperature and strain in ultrahigh temperature environment. A 3 × 3 matrix is used to characterize the cross sensitivity of the proposed sensor in which the strain sensitivity varies with temperature change. The proposed structure exhibits the deviation of 28.3 με and 4.1 °C at the ranges of 0-1000 με and 25 °C- 900 °C, respectively.