A study comparative between Magnetic Field Sensors Based on in-Fiber Fabry-Pérot cavity Interferometer and on etched side-hole Fiber

This paper presents a study comparative between two types of in-fiber Fabry-Pérot interferometers (FPI) and a commercial fiber Bragg grating (FBG) for magnetic field sensing. The first FPI sensor (FP1) was manufactured with a 273 $\mu$m section of capillary fiber. The other FPI sensor (FP2) was manufactured by etching the tip of a telecom SMF (germanium-doped) in hydrofluoric acid. The FPI sensors manufactured plus a commercial fiber Bragg grating (FBG), were bonded on a Terfenol-D piece. The results show that the FP2 sensor presented a sensitivity of 2.02 times higher than FP1 and 3.4 times higher than the FBG sensor.