Spatially Dispersive Finite-Difference Time-Domain Modelling of the Wire Medium for Subwavelength Imaging

Abstract

This paper presents the modelling of wire medium using a finite-difference time-domain (FDTD) method. The flat subwavelength lenses formed by the wire medium (lattices of parallel metallic wires) have been modelled in FDTD through the effect medium approach. The auxiliary differential equation (ADE) method has been applied in FDTD model in order to take into account both the frequency dispersion effect and the spatial dispersion effect which was found recently. The developed formulas have been implemented in a two-dimensional (2-D) FDTD model and validated by comparing transmission coefficient calculated from analytical solutions. The simulation results demonstrate the subwavelength imaging capability of the wire medium lenses.