Surface Plasmon Resonance Enhanced Polar Magneto-Optical Kerr Effects for Applications in Current Sensing

A novel current-detection mechanism based on surface plasmon resonance-enhanced polar magneto-optical effect is presented in this paper. Through the introduction of surface plasmon resonance technology and combined with hybrid nano-magnetic films, the current monitoring is indirectly realized by the real-time detection of exciting magnetic field around the wire. First, surface plasmon polaritons (SPPs) excitation properties of Au/Co/Au are analyzed to choose the most appropriate sample which can support highest intensity SPPs. Then, surface plasmon resonance effects in the magneto optical activity of chosen trilayers are studied. An enhancement of the magneto-optical Kerr signal under SPPs excitation as compared with that obtained without SPPs excitation is observed. Finally, the response of this sensing mechanism to current is investigated. Tests show that the maximum sensitivity is 0.10° /A. Analyses indicate that this new kind of magnetic sensor which based on SPR-enhanced polar magnetic-optical effect can be applied in the detection of large current.