Magnetoplasmonic crystal waveguide.

Abstract

We propose a perspective type of insulator-metal-insulator magnetoplasmonic crystal waveguide, composed of a gold grating placed between two garnet layers. Using an original non-perturbing method for the deposition of the upper magneto-dielectric layer, we fabricate the samples and provide experimental results evidencing the coupling of surface plasmon-polaritons propagating on the opposite Au/garnet interfaces. In contrast to traditional Au/garnet magnetoplasmonic crystals, spectra of the magneto-optical effect measured in transmission through this waveguide demonstrate rather specific features: a high-quality resonance for the long-range surface plasmon-polariton and a broad 60 nm wide resonance for the short-range surface plasmon-polariton. Our findings open new routes towards the development of high-sensitivity robust magnetoplasmonic sensors.