All-fiber-optic vector magnetometer based on anisotropic magnetism-manipulation of ferromagnetism nanoparticles

Abstract

The development of simple and sensitive sensors with the capability of simultaneously detecting magnetic field intensity and its direction in three-dimensional (3D) space is a technical imperative for magnetic field detection. In this paper, we first demonstrated the mechanism of anisotropic manipulation of ferromagnetism nanoparticles (FMNPs) in a non-continuous magnetic fluid film with the aid of varying magnetic fields. Second, based on the anisotropic distribution of the FMNPs around an optical fiber, we fabricated a vector magnetometer with a direction error of ±1.9° and an intensity sensitivity of 222.0 pm/mT, respectively. The sensing mechanism relies on the magnetism-controllable effective refractive index modification of asymmetric cladding modes in an in-line fiber-optic Mach-Zehnder interferometer. Compared to the previously reported intensity-based magnetometers, the as-fabricated magnetometer also provides an avenue to monitor the vector direction of the magnetic field in 3D space.

Magnetic Nanoparticles Functionalized Few-Mode-Fiber-Based Plasmonic Vector Magnetometer

“…When exposed to an applied magnetic field, the MNPs in the MF become magnetic dipoles and aggregate, forming stable chain-like structures oriented along the applied magnetic field direction [3]. However, the optical fiber in the MF destroys the original equilibrium state, forcing the MNPs to realign and form a new distribution around the fiber [23]. Moreover, the MNPs aggregate in an anisotropic manner: when the fiber surface is parallel (perpendicular) to the magnetic-field direction, they tend to gather to (depart from) the fiber surface [21,22].…”

“…This work revealed a new way to detect both the magnitude and orientation of a magnetic field. By creating a non-circularly-symmetric light-field in a fiber, Yin et al (2017) [22,23] developed two MF-based magnetic-vector sensors by sandwiching a piece of double-clad photonic-crystal-fiber or a thin core fiber between two single-mode fibers with a lateral offset. In 2018, based on a similar mechanism, magnetic-vector sensing was achieved by Layeghi et al, who used a tapered Hi-Bi fiber inserted in a fiber loop mirror [24].…”

A magnetic field sensor based on a dual S-tapered multimode fiber interferometer

“…It can be seen that, besides the fundamental frequency there is only one main frequency component in the Fourier frequency spectra of a single S-tapered fiber interferometer, and therefore it could be regarded as a two-mode fiber interferometer with a periodic interferometric spectrum. When certain magnetic field is applied, magnetic particles will be magnetized to form a nanochain-like structure paralleled to the field direction [36]. Phase separation will occur during this process, causing the variation in effective dielectric constant [37].…”

Design of a Magnetic-Sensor Based on Fe3O4 Nanofluid Infiltration

“…The field of magnetic sensors has seen rapid progress, Wang et al [2] demonstrated a magnetic sensor based on dual-core PCF. Chen et al [3] formed a sensor based on anisotropic of magnetic fluid (MF) particles. A Mach-Zehnder Interferometer (MZI) fiber was coated with MF to build a sensor [4].…”