Surface waves radiation by finite arrays of magnetoelectric resonators

Abstract

We study the propagation of waves on infinite and finite size arrays made of subwavelength magnetoelectric resonators. We propose an analytical study where each magnetoelectric resonator is modelled simultaneously by an electric and a magnetic dipole. We show how near field coupling and wavenumber quantification due to the finite size of the structure induce a frequency splitting of the resonator fundamental mode.We theoretically demonstrate that despite a spatial period of the waves smaller than half wavelength (in vacuum), the structure can efficiently emits radiations. An analytic expression of the Q factor associated to the radiation losses is proposed. To correctly estimate this factor, we show that not only near but also far field interaction terms between the dipoles must to be considered.