Magnetic field and temperature sensor based on D-shaped fiber modal interferometer and magnetic fluid

A novel optical fiber magnetic field sensor based on D-shaped fiber modal interferometer and magnetic fluid is proposed and experimentally investigated. Thanks to the etched cladding of D-shaped fiber, the resulting interference is strongly influenced by the surrounding magnetic fluid, which leads to a high magnetic field sensitivity. Simultaneous measurement of the magnetic field and temperature was realized by monitoring the wavelength shift of the two resonance dips at the same time. In the experiment, the magnetic field and temperature sensitivity can reach 99.68 pm/Oe and −77.49 pm/°C, respectively. The proposed magnetic field sensor based on D-shaped fiber is featured with high sensitivity, low cost and simple configuration.