Magneto-optical response of Cu/NiFe/Cu nanostructure under surface plasmon resonance

• Large magneto-optical response in Cu/NiFe/Cu multilayer nanostructure is achieved.
• Layer thickness and sequence are studied to find large transverse Kerr signal.
• Hybridization of surface plasmon excitation and cavity resonance were done.

In this paper, we present theoretical and experimental studies about the surface plasmon resonance effects on the magneto-optical activity of Cu/NiFe/Cu nanostructures as a function of layers thickness and light incident angle. Device fabrication was done by an oblique deposition technique with RF magnetron sputtering to carefully cover fine step thickness variation of all constituted layers. Angular dependent transverse Kerr response of samples was measured in the Kretschmann configuration at a fixed wavelength of 632 nm. At an optimum layer thickness and incident angle, significant amplification of the transverse Kerr effect was observed. Enhancement in the transverse Kerr effect can be realized by hybridization of surface plasmon excitation and cavity resonance in the plasmonic nanostructure. Experimental results were in qualitative agreement with modeling based on the 4×4 transfer matrix formalism.