A High Sensitivity Temperature Sensing Probe Based on Microfiber Fabry-Perot Interference

In this paper, a miniature Fabry-Perot temperature probe was designed by using polydimethylsiloxane (PDMS) to encapsulate a microfiber in one cut of hollow core fiber (HCF). The microfiber tip and a common single mode fiber (SMF) end were used as the two reflectors of the Fabry-Perot interferometer. The temperature sensing performance was experimentally demonstrated with a sensitivity of 11.86 nm/degrees C and an excellent linear fitting in the range of 43-50 degrees C. This high sensitivity depends on the large thermal-expansion coefficient of PDMS. This temperature sensor can operate no higher than 200 degrees C limiting by the physicochemical properties of PDMS. The low cost, fast fabrication process, compact structure and outstanding resolution of less than 10(-4) degrees C enable it being as a promising candidate for exploring the temperature monitor or controller with ultra-high sensitivity and precision.