Slanted annular aperture arrays as enhanced-transmission metamaterials: Excitation of the plasmonic transverse electromagnetic guided mode

We present here the fabrication and the optical characterization of slanted annular aperture arrays engraved into silver film. An experimental enhanced transmission based on the excitation of the cutoff-less plasmonic guided mode of the nano-waveguides (the transmission electron microscopy mode) is demonstrated and agrees well with the theoretical predicted results. By the way, even if it is less efficient (70% -> 20%), an enhanced transmission can occur at larger wavelength value (720 nm-930 nm) compared to conventional annular aperture arrays structure by correctly setting the metal thickness. (C) 2013 AIP Publishing LLC.