*et al*. [@Husnik08], and Banzer *et al*. [@Banzer10] that quantify the extinction cross section of single split rings under differently polarized illumination, as well as a suite of experiments on coupled systems. These experiments include extinction measurements on split ring dimers [@Feth10] that point at resonance hybridization, as well as reports of magnetization waves [@decker09], structural and geometrical chirality in arrays, as evident in e.g. massive circular dichroism [@Gansel09; @Plum09; @Plum09b; @Zhang09; @Wang09; @plum07; @decker07; @decker10], and chiral effects in split ring stereo-dimers studied by Liu *et al*. [@Giessen09].

In order to understand the light-metamatter interaction in systems of strongly coupled magneto-electric scatterers, it is important to understand how individual metamaterial building blocks are excited and how they scatter. So far, explanations of the observed phenomena have mainly rested on two pillars. On the one hand, data are compared to brute force finite-difference time-domain (FDTD) simulations of Maxwell’s equations, usually showing good correspondence [@Smith00; @Enkrich05; @Rockstuhl06b; @Klein06; @Husnik08; @Gansel09; @Plum09]. While the FDTD method is a rigorous method, such numerical experiments do not in themselves provide insight into how split rings scatter or hybridize in coupled systems. There is general consensus that to lowest order, metamaterial interactions in lattices of 