Plasmonics is an emergent area of the nanophotonics that studies interaction between electromagnetic fields and free electrons in a metal on a metal/dielectric interface. Due to this interaction, the called surface plasmon polaritons (SPP) are generated. SPPs are electromagnetic excitations coupled to the collective oscillation of conduction electrons, which propagate along the interface between a conductor and a dielectric medium, with a broad range of applications, from photonics to bioengineering. One of the basic concepts related to SPPs is the dispersion relation, basic for understanding of the interaction between light and metallic nanostructures. In this paper we derive the dispersion relation of surface plasmon-polariton at planar interface and its fundamental properties are outlined.
Keywords: plasmonic; surface plasmon; surface plasmon polariton