Influence of the filling factor on the spectral properties of plasmonic crystals

摘要: Plasmonics crystals (PCs) comprised of finite-size triangular lattices gold bumps deposited on a thin film are studied by means near-field optical microscope. The plasmonic fabricated electron-beam lithography illuminated an incident surface plasmon polariton excited in the Kretschmann-Raether configuration at gold/air thin-film interface for free-space wavelengths range $740--820\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. Based measurement (SPP) damping distance crystals, existence band gap SPP traveling along two symmetry axes $\ensuremath{\Gamma}M$ and $\ensuremath{\Gamma}K$ is demonstrated. By increasing lateral size bumps, influence filling factor PC spectral properties investigated. We show that, axes, central frequency depends only weakly factor, whereas we observed neat band-gap broadening factors. experimental results found to be consistent with structures computed differential method. In particular, good agreement between theoretical frequencies obtained. Finally, investigate origin PCs computing modal reflectivity (or in-plane reflectivity) semi-infinitely extended crystals. From these calculations, that propagation through inhibited distributed reflection not losses channels such as absorption or out-of-plane scattering.