Optical Near-Field Characterization of Plasmonic and Magnetoplasmonic Nanostructures

Abstract

Most plasmonic devices are passive devices since their electromagnetic properties depend mainly on fixed properties such as the shape of the structures, their constitutive materials, and the dielectric media. A way to turn plasmonic devices into active ones is to use ferromagnetic metals, since due to their magneto-optical (MO) activity the optical response when applying an external low magnetic field can be modified. Unfortunately, plasmon resonances are critically broadened in ferromagnetic materials due to their important electromagnetic losses. An alternative is to combine ferromagnetic materials with noble metals. Recently, we have demonstrated that Au/Co/Au nanodisks exhibit enhanced magnetoplasmonic properties such as a significant increase of the MO activity when the localized surface plasmon (LSP) resonance is excited [1,2].