Hedgehog subwavelength hole arrays: control over the THz enhanced transmission
UPNa. Departamento de Ingeniería Eléctrica y Electrónica. Laboratorio de Ondas Milimétricas y Terahercios ; By backing or sandwiching a holey metal layer with or between isotropic dielectric slabs, additional peaks of transmission within the long-wavelength regime arise as a result of the induced transverse magnetic (TM) or transverse electric (TE) grounded dielectric modes. A similar control of the complex surface wave modes, and thus of the extraordinary transmission (ET) peaks, is demonstrated here via anisotropic slabs in the form of a fakir's bed of nails. However, it is shown that those ET peaks formed from TE modes are suppressed because of the inherent dispersion characteristics of the free-standing grounded pins. This allows the red-shifting of the ET for the polarization parallel to the larger in-plane period of the hole array, but unlike the dielectric isotropic slab configuration, the orthogonal polarization remains inhibited. ; This work was sponsored by the Spanish Government and European Union funds under contracts Consolider 'Engineering Metamaterials' CSD2008- 00066 and TEC2011-28664-C02-01. MN-C is supported by Imperial College through a Junior Research Fellowship. PR-U is sponsored by the Government of Navarre via the program 'Formación de Tecnólogos' 055/01/11. MB is sponsored by the Spanish Government via RYC- 2011–08221.