Real-k-space analysis of electromagnetic waves in a plasmonic waveguide metamaterial

Plasmonic waveguide metamaterials are some of the most promising structures for achieving a negative index of refraction at optical frequencies. In this paper, we analyze one such structure through a three-dimensional Fourier decomposition of electromagnetic fields into plane-wave components with purely real wave vectors. The visual depiction of the Poynting vector associated with each plane wave component in real-k space provides intuitive insights into the electromagnetic response of this medium.