A High-Sensitivity Temperature Sensor Based on Glycerol-Filled Tellurite Microstructure Optical Fiber

A high-sensitivity temperature sensor was fabricated based on a tellurite microstructure optical fiber (MOF) sandwiched between two standard silica single mode fibers to form a single mode-multimode-single mode fiber structure. Glycerol with high thermo-optical coefficient was filled into the air holes of the tellurite MOF as its thermal medium. The temperature change can be obtained by the movement of the output spectrum based on multimode interference effect, and the experimental sensitivity reaches as high as 273 pm/°C at the working wavelength around 1.95 μm. By conducting comparative experiments, the sensor in this work is proved to be a highly sensitive, compact, robust sensor operating at the near- and mid-infrared wavelength range.