Development of a Multimaterial Optical Fiber for Fully Distributed Magnetic Sensing Applications

• Published in: IEEE sensors letters Vol. 6; no. 1; pp. 1 - 4
• Main Authors: Hileman, Zachary, Homa, Daniel, Ma, Lingmei, Dong, Bo, Martin, Eileen, Pickrell, Gary, Wang, Anbo
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.01.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amorphous magnetic materials; Bragg gratings; distributed acoustic sensing (DAS); Ferromagnetism; Fiber optics; Fused silica; Magnetic sensors; Magnetoacoustic effects; Magnetostriction; Manufacturability; Microscopes; Optical fiber polarization; Optical fiber sensors; Optical fibers; Sensitivity; Sensors; Silicon dioxide
• ISSN: 2475-1472; 2475-1472
• DOI: 10.1109/LSENS.2021.3137640

A novel multimaterial fiber optic magnetic sensing design is presented and evaluated in this letter. The multimaterial optical fiber has demonstrated <inline-formula><tex-math notation="LaTeX"> < 0.2\ n\epsilon </tex-math></inline-formula> sensitivity to external magnetic fields over a 2-m gauge length. Intended for immediate use in unconventional oil and gas (UOG) and measuring while drilling (MWD), this instrument could have wide-ranging subsurface sensing applications. Composed of fused silica cladding, internally distributed ferromagnetic nickel, and a series of fiber Bragg gratings, the multimaterial structure has been consistently drawn to over 1 km of length on a fiber draw tower. Due to the consistency of manufacturability and high magnetic sensitivities over long lengths, the proposed design may be considered a competitive magnetic sensor in UOG and MWD applications.