A Novel Current-sensing Mechanism Based on Surface Plasmon Resonance Enhanced Polar Magneto-optical Kerr Effect

摘要

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 combination with hybrid nano-magnetic films, current monitoring is indirectly realized by the real-time detection of magnetic field excited 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 most intensive SPPs. Then, the effects of surface plasmon resonance in the magneto-optical activity of chosen trilayer are studied. An enhancement of the magneto-optical Kerr signal under SPPs excitation as compared with that obtained without SPPs excitation is observed. The magneto-optical enhancement ratio varies when Co become thicker and get a maximum with a certain thickness. Meanwhile, the 4*4 transfer matrix method is used to simulate the SPR spectra, polar MO Kerr spectra and the enhancement effects. Finally, an electromagnetic coil is designed. Tests show that when the magnetic field gets 338Guass, the polar Kerr rotation of chosen sample changes 0.057° . Experimental and theoretical results indicate that this new kind of magnetic sensor which based on SPR-enhanced polar magneticoptical effect can be applied in the detection of current.