A tapered multicore fiber sensor for measuring temperature and magnetic field

Abstract

Tapered multicore fiber (TMCF) has been used to realize versatile optical fiber sensor for high sensitivity temperature and magnetic field sensing. The TMCF was melted to two multimode fibers (MMF) to sense the temperature, and the sensitivity reached up to 453.80 pm/℃ with linearity of ∼0.993. The MMF-TMCF-MMF structure was wrapped in polydimethylsiloxane (PDMS) to measure the response of the proposed sensor to temperature. The sensitivity increased up to −693.20 pm/℃, and the linearity was 0.997. These results show that the TMCF-based sensor has a very sensitive linear response to temperature, and the PDMS enhances the temperature sensitivity. An MMF-TMCF- MMF structure was wrapped in a mixture of PDMS and iron powder of the Titanium Doped Iron Oxide (Fe2O3-Ti) to measure the response characteristics of the magnetic field, showing sensitivity at the level of ∼-0.07 dB/mT, with linearity of 0.987. An MMF-TMCF-MMF structure was wrapped in magnetic fluid used to sense the magnetic field, giving the sensitivity of 172.60 pm/mT. The versatile sensor has small structure, stable performance, and simple fabrication, and it can be used in temperature/magnetic field sensing, respectively.