Surface plasmon

The charge motion in a surface plasmon always creates electromagnetic fields outside (as well as inside) the metal.

[1] In the following two decades, surface plasmons were extensively studied by many scientists, the foremost of whom were T. Turbadar in the 1950s and 1960s, and E. N. Economou, Heinz Raether, E. Kretschmann, and A. Otto in the 1960s and 1970s.

Localized surface plasmons arise in small metallic objects, including nanoparticles.

[7] LSPs can be excited directly through incident waves; efficient coupling to the LSP modes correspond to resonances and can be attributed to absorption and scattering, with increased local-field enhancements.

In SPR, the maximum excitation of surface plasmons are detected by monitoring the reflected power from a prism coupler as a function of incident angle or wavelength.

Recent works have also shown that SPR can be used to measure the optical indexes of multi-layered systems, where ellipsometry failed to give a result.

[11] This approach has been shown to have a high potential for nanoscale light manipulation and the development of a fully CMOS-compatible electro-optical plasmonic modulator, said to be a future key component in chip-scale photonic circuits.

The electric field is stronger at the interface because of the surface plasmon resulting in a non-linear optical effect.

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.
Lossless dispersion curve for surface plasmons. At low k , the surface plasmon curve (red) approaches the photon curve (blue)