Low magnetic field detection via nanometre scale air-holes photonic crystal fiber filled with magnetic fluid

摘要

A novel and highly-sensitive magnetic field sensor is experimentally demonstrated employing nanometer sized air-holes photonic crystal fiber (PCF) infiltrated with magnetic fluid (MF). The MF is a functional fluid with tunable refractive index in response to external magnetic field. The transmitted light intensity variation through the MF-PCF under magnetic field was measured. The proposed sensor exhibited a smooth response with high correlation coefficient of 0.999 with a second-order equation. The designed sensor was able to measure magnetic field as low as 2 Gauss, which is one of the weakest value reported to date for fiber-optic magnetometers. The compact size, simple interrogation scheme and high sensitivity makes it a promising candidate for high-precision biosensing applications.