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

Sensors (Basel). 2017 Oct 20;17(10):2393. doi: 10.3390/s17102393.

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.

Keywords: magnetic fiber optic sensor; optical signal processing; tapered optical fibers.