FIRST-PRINCIPLE ANALYSIS FOR ELECTROMAGNETIC EIGEN MODES IN AN OPTICAL METAMATERIAL SLAB

Electromagnetic (EM) eigen modes in a fishnet metamaterial (MM) slab have been comprehensively analyzed in an experimental configuration, based only on precise solutions of Maxwell equations. The EM eigen modes were directly detected from light-absorption peaks. Each mode was explicitly characterized by the dispersion diagram and EM field distributions. It was consequently found that the modes were classfied into either inner modes inside the slab or a mode at the interface with the surrounding media. The symmetric properties of the inner modes were clarified using group theory. The interface mode was found to come from surface plasmon polariton at flat metal/insulator interface. The present analysis procedure is generally applicable to MM slabs and enables to clarify the properties without models or assumptions, which have been usually used in MM studies.