Simultaneous measurement of strain and temperature using a high-birefringence fiber loop mirror and an erbium-doped fiber

A fiber sensor configuration suitable for simultaneous measurement of temperature and strain is investigated. The sensor consists of a high-birefringence fiber loop mirror concatenating with an erbium-doped fiber. The high-birefringence fiber used in the configuration is capsule shaped polarization maintaining fiber, which serves as the sensor element. While the erbium-doped fiber acts as the temperature compensation module. By monitoring the peak power variation and peak wavelength shift, it is feasible to simultaneously measure temperature and strain. The experimental results show that the mean square errors for temperature and stain are 0.35°C and 13.34με, respectively. The proposed sensor configuration shows several merits, including simple in structure, easy fabrication, low cost and high sensitivity.