All-fiber temperature sensor based on Fabry-Perot interferometer

An all-fiber Fabry-Perot interferometric sensor is demonstrated both theoretically and experimentally. The proposed structure is designed and fabricated by chemical etching combined with arc discharge welding and tapering. The single-mode fiber (SMF-28) with one end face flattened is inserted vertically into the hydrofluoric acid, then welded with another SMF-28 by arc discharge, to form a bubble by welding and tapering, which exhibits a three-beam interference phenomenon. High-temperature sensitivity of 12.88 pm/°C is obtained at the large temperature range from 50 to 300 °C, with excellent linearity of 0.9956. The Fabry-Perot Interferometer , with low processing cost and high performance, can provide a useful application in temperature sensing prospects.