Resonant nanometric cross-shaped apertures: Single apertures versus periodic arrays

Here localized surface plasmon (LSP) resonances occurring inside cross-shaped apertures arranged in thin metallic films are investigated. It is shown that these resonances can be controlled by altering the geometry of the apertures, whereas surface plasmon polariton excitation and Wood anomalies arising as a consequence of the periodicity distorts the spectrum produced by isolated LSP resonances. Simulations showing the behavior of single apertures versus periodic arrays of apertures are compared with experimental results for periodic arrays.