Terahertz time-domain spectroscopy studies of subwavelength hole arrays in metallic films

We studied the phenomenon of ‘anomalous transmission’ in various subwavelength hole arrays in metallic films, using the terahertz (THz) time-domain spectroscopy technique. The perforated samples were heavily doped polypyrrole conducting polymer films patterned with hole arrays in the form of square Bravais lattice. The enhanced transmission in perforated heavily doped polypyrrole films exhibit characteristic properties that can be tuned through chemical synthesis and alteration of the doping level, allowing novel optical devices to be fabricated in the THz spectral range.