Magneto-optically-controlled surface plasmon excitation

The diffraction of a plane wave by a magneto-optical cavity located on a metal interface is investigated. We show that the excitation of localized eigenmodes of the cavity allows one to efficiently excite the surface plasmon polariton (SPP). We exploit the symmetry properties of the cavity modes to propose a new method for controlling the SPP intensity through an external magnetic field. Our theoretical predictions are in good agreement with the rigorous computations based on the generalized Lorentz reciprocity theorem and aperiodic Fourier modal method.