Extraordinary transmission of nanohole lattices in gold films

We study experimentally the transmission of light through a square lattice of nanoholes perforated in a optically-thick gold film. We observe that the periodicity of the structure enhances the light transmission for specific wavelengths, and we analyze this effect theoretically by employing finite-difference time-domain numerical simulations. Furthermore, we investigate the possibilities for manipulation of the spectral transmission in quasi-periodic and chirped lattices consisting of square nanoholes with varying hole size or lattice periodicity.