Magnetic Field Sensing Based on Bi-Tapered Optical Fibers Using Spectral Phase Analysis

Abstract

A compact, magnetic field sensor system based on a short, bi-tapered optical fiber (BTOF) span lying on a magnetic tape was designed, fabricated, and characterized. We monitored the transmission spectrum from a broadband light source, which displayed a strong interference signal. After data collection, we applied a phase analysis of the interference optical spectrum. We here report the results on two fabricated, BTOFs with different interference spectrum characteristics; we analyzed the signal based on the interference between a high-order modal component and the core fiber mode. The sensor exhibited a linear response for magnetic field increments, and we achieved a phase sensitivity of around 0.28 rad/mT. The sensing setup presented remote sensing operation and low-cost transducer magnetic material.

Ferromagnetic Resonance Vector Magnetic Sensor with High Sensitivity and Ultrawide Working Range

“…According to the relationship between magnetic field variation and phase variation in Figure 3a, the magnetic sensitivity of the sensor can be obtained as 20.15 Deg per mT by linear fitting. The sensitivity value is higher than the 16.05 Deg per mT of the optical fiber interference sensor [ 34 ] but lower than the 174.1 Deg per mT of the giant magnetic‐impedance sensor [ 35 ] (16 cm in length). Compared with these traditional bulky sensors the FMR sensor has obvious advantages of high integratability and low energy consumption.…”

Fiber structures and material science in optical fiber magnetic field sensors

“…10) [47]. The light leaks out from the taper waist and forms the evanescent field, which interacts with the surrounding environment [48][49][50][51].…”