Sagnac Interferometer Temperature Sensor Based on Microstructured Optical Fiber Filled with Glycerin

A Polarization-maintaining photonic crystal fiber (PMPCF) temperature sensor was designed and implemented based on Sagnac interference. The glycerin solution was used as the photosensitive material. According to the finite element method, it was found that the temperature sensor obtained the highest sensitivity when the PMPCF was filled with the glycerin solution with a mass fraction of 70%. In the experiment, with the temperature increasing from -25 ℃ to 85 ℃ with a step of 5 ℃, a linear fit was made between the dip wavelength and the temperature. The results have shown that the highest temperature sensitivity of 1.5005 nm/℃ was obtained for the proposed sensor within the temperature range of -25 ℃ to 85 ℃ which was wider than that of the previous work and implied the good potentiality for temperature measurement application.