Surface plasmon polaritons, as the precise term would be, constitute an excitation where an electromagnetic field is coupled to the density oscillations of the conduction electrons in a metal. They share properties of the electromagnetic field as well as from the plasmon. Basically, localized and propagating surface plasmon polaritons can be distinguished. They are either sustained at isolated metallic nanostructures or at the extended interface between a metal and a dielectric, respectively. They allow to localize energy in spatial domains much smaller than the optical wavelength, they sustain huge electromagnetic fields, and they sustain a resonant response usually in a narrow frequency domain. They are the ideal means to mediate light between a macroscopic and a nanoscopic world.
Presently, we focus in our group on analyzing the scattering properties of small metallic nanoparticles with complicated shapes, the properties of metallic waveguides, and their use in various applications from other fields of science.