"In this Chapter, the role of complex artificial structures in enhancing the power transmission through sub-wavelength apertures is discussed. Such devices are aimed at exciting highly localized resonances in order to increase the aperture equivalent magnetic and electric dipole moments. Some examples, based on epsilon-near-zero metamaterials (ENZ), frequency selective surfaces (FSSs) and split-ring resonators (SRRs) at microwaves, and silver nano-particle pairs at terahertz scale, are presented. Such structures may find applications in different fields, such as high-resolution spatial filters, ultra-diffractive imaging systems, high-capacity optical memories, enhanced light throughput tips for nears-field scanning optical microscopes, etc."
Bilotti, F., L., S., K. B., A., K., A., O. A., C., E., O., et al. (2011). Enhanced transmission through sub-wavelength apertures by using metamaterials. In A.C. A. Andreone (a cura di), “Selected Topics In Photonic Crystals And Metamaterials,” Ed. A. Andreone, A. Cusano, V. Galdi, A. Cutolo, World Scientific Pub., 2011, pp.453-477 (pp. 455-479). World Scientific Publishing Company.