Tunable nanowires: An additional degree of freedom in plasmonics

We report on the excitation of surface plasmon polaritons (SPP’s) on a periodic arrangement of metallic ribbons with tunable periodicity. The ability to vary its lattice constant results in an additional degree of freedom, permitting excitation of SPP’s for any combination of wavelength and angle of incidence within the tuning range of the system. Moreover, the designed smart material allows fundamental questions to be answered regarding SPP propagation and localization. Finally, the concept opens vistas in the development of other methodologies in spectroscopy including plasmonic sensors and chips.