Giant nonlinear magneto-optical response of magnetoplasmonic crystals

Abstract

Magnetoplasmonics provides unique possibilities for magnetic field control over light flow. A special interest in this field is attracted to magnetoplasmonic crystals (MPCs) that are nanostructured metal-dielectric materials with rich resonant spectra that can be tuned by a magnetic field. We show that MPC demonstrates enhanced nonlinear-optical effects such as optical second harmonic generation (SHG) and a giant nonlinear magneto-optical effect. Contrary to the linear-optical case, the main mechanism underlying the observed effects is the resonant enhancement of the local field achieved both for the surface-plasmon-polariton modes at metal/dielectric interfaces and for the waveguide modes in a dielectric slab, which provides an up to 25% magnetic field controlled SHG intensity variation. These effects are treated as an interplay of excitation of different modes that leads to Fano-type resonances in the nonlinear-optical response.