Magnetic field sensor based on plasmonic fiber optics coupled with smartphone

Abstract

In this study, a plastic optical fiber sensor covered with spherical gold nanoparticles is described for detecting the magnetic field. The sensor operation is based on surface plasmon resonance, which is because of the interaction between the guided modes in optical fiber and the surface plasma waves supported by gold nanoparticles. The proposed sensor has three optical fibers as reference, measurement and control fiber. The sensing region in measurement fiber coated with gold spherical nanoparticles that are made with laser ablation. In addition, the control and reference fiber used to reduce more sensitive fluctuations in system. The intensity of the output light of the fibers recorded by the smartphone camera. Recorded videos are processed and finally the intensity graph is obtained in terms of time. It is observed that in the absence of a magnetic field, the intensity of light output from the measurement fiber is low due to the absorption of spherical gold nanoparticles. By applying the magnetic field, this amount is lower, due to the coupling between the magnetic field and the plasmonic properties.