ABSTRACT
This chapter focuses on the optical transmission properties of arrays of subwavelength slits, for p-polarized light. In 1998, T. W. Ebbesen and coworkers found experimentally that the transmission of light thorough a periodic array of subwavelength holes, drilled in a metal film, showed strong resonant peaks. More estimations, based both on calculations for the transmittance of an isolated hole in a real metal and precise measurements of the single hole transmittance, have lowered the transmission enhancement in typical extraordinary optical transmission (EOT) samples to factors of the order 10–100. Electromagnetic wave transmission mediated by surface modes has also been found in perforated metals in the THz and millimeter regimes, doped semiconductors, perforated polar semiconductors in the infrared regime and holey slabs made of photonic crystals. For frequencies lower than optical ones, and for EOT phenomena, most metals behave as a perfect conductor.
