Analytical theory and equivalent circuit for extraordinary transmission through arrays of slits perforated in realistic metallic screens

We propose an analytical theory of extraordinary optical transmission (EOT) through lossy metallic screens perforated by a periodic array of subwavelength slits. The theory is based on our previous work on EOT through perfect conducting screens and on the surface impedance concept. Good agreement with electromagnetic simulations is found for all frequency range where EOT has been reported, including microwaves and optics. We also show how a simple transmission-line equivalent circuit model can be inferred from the analytical results.