ABSTRACT
The interaction of metals with electromagnetic radiation is largely dictated by the behavior of free electrons in the metal. Plasmons play an important role in the optical properties of metals. Localized surface plasmons exist at the surface of metallic nanostructures such as nanoparticles, nano-holes, and grooves, where the structures have dimensions comparable to or smaller than the wavelength of light. Localized surface plasmon resonances are collective electron charge oscillations in metallic nanostructures that are excited by incident light. Theoretical and experimental works on metal plasmonics have mostly been carried out with gold, silver and aluminum, which are all good plasmonic materials. Plasmonic colors are structural colors that emerge from resonant interactions between light and metallic nanostructures. The engineering of plasmonic colors is a rapidly developing, promising research field that has a large technological impact. Plasmonic antennas enable sub-wavelength localization of the electromagnetic energy and wavelength-selective optical extinction. Arrays of aluminum nanoantennas have been used to demonstrate chromatic plasmonic polarizers.
