ABSTRACT
Bulk plasmons, considered in the previous chapter, can exist only in
the transparency region of metals and cannot be localized strongly,
since at a given frequency their wavelengths are greater than light
wavelengths in free space. In this respect, plasmon oscillations
of this kind are irrelevant to nanoplasmonics. More interesting
plasmon oscillations arise on the metal-dielectric interface. As it
will be shown further, plasmons of this kind can exist in the opacity
region (ε′ < 0) of metal and have a strong spatial localization at optical frequencies. Such oscillations can occur in two dimensions
(e.g., planar metal-dielectric interface) and even in one dimension
(metal nanowire). Plasmons of this type are called surface plasmons,
and it is their properties that will be considered in this chapter.
