Enhancement of the sensitivity of ferrofluidic magneto-optical fiber sensor by non-adiabatic tapered Hi-Bi fiber in fiber loop mirror

摘要

A magnetic field fiber optic sensor based on Nano-magnetic fluid and Hi-Bi non-adiabatic tapered optical fiber in fiber loop mirror (HB-TFLM) is proposed and theoretically explained. As compared to the reported magnetic fluid (MF) based sensors, the achieved sensitivity of the proposed sensor is 255 pm/mT, which is enhanced by 3.6 times of magnitude relative to in line non-adiabatic tapered optical fiber sensor, used only 0.1% of the volume concentration of MF nanoparticles. Detection limit of the HB-TFLM to external magnetic field in range from 0 to 21 mT and 22 to 50 mT was 7.8 μT and 39.2 μT, respectively.