| Surface Plasmon Polaritons (SPPs) are the excitation of the electromagnetic field at the interface between metal and dielectric due to coupling of surface plasma with the photon. The dispersion relation of SPPs wave vector with the photon wave vector in free space has been established and found that SPPs momentum is greater than that of photon for given frequency of light shining on the interface. The properties of SPPs like as propagation length along the metal-dielectric interface, penetration depth of the SPPs field intensity into both medium and the complex dielectric function of the metal which is a function of frequency of photon hitting on it have been studied. Since due to mismatch momentum between photon and SPPs, different techniques using prism and grating on the metal surface to erase the momentum gap between the SPPs and photon have been described briefly, So the excitation of the SPPs can be done for various range of incoming photon energy. |
