ACS Nano 2011 , 5 (8), pp 6701–6706.
Link to paper

B. Ögüt, R. Vogelgesang, W. Sigle, N. Talebi, C. Koch, P. van Aken.

By energy-filtering transmission electron microscopy (EFTEM), we observe Fabry-Prot-like surface plasmon resonances (SPRs) along the length of rectangular single and double slits drilled into free-standing thin silver films. These eigenmodes hybridize in closely situated slits. The nature of their lateral coupling is uncovered from finite-element simulations, which show that the symmetry and energy sequence of hybrid modes is governed by Babinet complementarity principles. Interestingly, the modes of a double slit system, being proto-self-complementary, may alternatively be explained by magnetic interactions between slit fields or by electrostatic interactions across the metallic bridge separating the slits.

http://pubs.acs.org/doi/abs/10.1021/nn2022414