Advances on circuit modeling of extraordinary transmission

Extraordinary optical transmission (EOT) is a phenomenon which has received extraordinary attention since its discovery, twelve years ago. The phenomenon takes place at any frequency range - not only at the optical regime -, and it has been explained in terms of the excitation of surface waves along the periodically structured metal screens used in the experiments. EOT also takes place, however, through slit gratings for a polarization precluding the excitation of such surface waves. It can be also observed through electrically small diaphragms located inside hollow pipe waveguides. Along the last three years, some of the authors have developed models explaining the phenomenon in terms of simple concepts extracted from conventional waveguide theory. The models lead themselves to simple circuit equivalents which help the understanding of the underlying physics. This paper summarizes the main results obtained by the members of the group and some other collaborators concerning the capabilities of the proposed approach.