Highly Sensitive Fiber‐Optic Intrinsic Electromagnetic Field Sensing

Abstract

Fiber‐optic sensing is resistant to electromagnetic interference; therefore, electromagnetic field sensing using fiber‐optic sensors is challenging. Herein, the first demonstration of fiber‐optic intrinsic electromagnetic field sensing based on modal interferometry with the highest reported sensitivity is presented (here, to be intrinsic means that the magnetic field interaction occurs only within the optical fiber, where there is no use of magnetic fluids or extrinsic structures). A fused polymer optical fiber (POF) is connected to two silica single‐mode fibers (SMFs) through an UV‐curing resin. Another interferometer with a nonfused POF is also fabricated, and the transmitted spectra of both the interferometers are compared in the presence of an electromagnetic field (0–240 mT). The results show the insensitivity of the nonfused POF interferometer and a mean sensitivity of 16.7 pm mT−1 for the fused POF interferometer, which presents a tenfold increase by changing the fused POF length from 2 to 5 cm, resulting in a sensitivity of 113.5 pm mT−1. The proposed intrinsic electromagnetic field sensor has the potential of measuring magnetic field intensities as low as 45 μT (considering its high sensitivity) with possibility of further increase with small changes in the signal acquisition components.

Sensing Applications of Polymer Optical Fiber Fuse

“…[ 43 ] These effects result not only in the changes on refractive index, polarization, and so on, but also in the change of shape in magnetostrictive materials. Compared with the nonfused POF, the fused POF shows a 30 times higher magnetostriction, [ 44 ] which confirms the possibility of using the fused POFs in optical devices such as an intrinsic magnetic field sensor.…”

Optical Sensing Using Fiber-Optic Multimode Interference Devices: A Review of Nonconventional Sensing Schemes

“…Last year, 2020, Leal-Junior et al reported a fiber-optic intrinsic electromagnetic field sensor based on modal interferometry [ 69 ]. The sensor uses a short section of POF sandwiched between two SMFs.…”

U-Shaped Optical Fiber Probes Coated with Electrically Doped GQDs for Humidity Measurements

“…In 1992, Hagen Renner et al [28] proposed that when single-mode optical fibers experience bending, the transverse field distribution ψ(x,y) in the optical waveguides can be expressed as the two-dimensional scalar equation, as shown in Equation (1).…”

“…Optical fibers are part of everyday life, especially in communications, where they are used to convey information. Optical fibers have various advantages: low weight, small radius, high stability, high sensitivity, imperviousness to electromagnetic interference, and a high tolerance for harsh environmental conditions [ 1 , 2 ]. Due to their high sensitivities, optical fibers are widely applied in communications and have also displayed excellent performance in sensing and measurement applications [ 3 ].…”