Magnetic Field Sensor Based on a Tri-Microfiber Coupler Ring in Magnetic Fluid and a Fiber Bragg Grating

fangfang Wei, Technological University Dublin
Dejun Liu, Shenzhen University
Arun Mallik, Technological University Dublin
Gerald Farrell, Technological University Dublin
Qiang Wu, Northumbria University
Gang-Ding Peng, University of New South Wales
Yuliya Semenova, Technological University Dublin

Document Type Article

Scientific Reports, 7(1), pp. 4725, Jul. 2017, doi: 10.1038/s41598-017-05199-y

Abstract

In this paper we propose and investigate a novel magnetic field sensor based on a Tri-microfiber coupler combined with magnetic fluid and a fiber Bragg grating (FBG) in a ring. A sensitivity of 1306 pm/mT was experimentally demonstrated in the range of magnetic fields from 0 to 15 mT. The reflection peak in the output spectrum associated with the FBG serves as a reference point allowing to avoid ambiguity in determining the spectral shift induced by the magnetic field. Due to its high sensitivity at low magnetic fields, the proposed structure could be of high interest in low field biosensing applications that involve a magnetic field, such as magnetic manipulation or separation of biomolecules.