English: Schematic representation of an electron density wave propagating along a metal/dielectric interface. The charge density oscillations and associated electromagnetic fields are called surface plasmon-polariton waves. The exponential dependence of the electromagnetic field intensity on the distance away from the interface is shown on the right. These waves can be excited very efficiently with light in the visible range of the electromagnetic spectrum.

Presently, metallic nanostructures are used to fabricate/analyze:

• Sub-diffraction limit optical waveguides based on metallic nanoparticle arrays and nanowires.
• Plasmon excitations on thin films with ordered arrays of holes.
• Ultra-sensitive optical sensors for biological applications.
• Electronic interconnects.