ABSTRACT
Localized surface plasmons (LSPs) are nonpropagating excitations
of the free-electron plasma in metal nanostructures excited by
electromagnetic radiation at optical frequencies [1]. The optical
excitation of LSPs results in the formation of hot spots featuring
high electric field enhancement over subwavelength spatial regions.
This effect opens up a wide range of device applications [2], such as
solar cells, plasmon-enhanced photodetectors, optical manipulators,
modulators, thermal emitters, surface-enhanced Raman scattering
substrates, apertureless near-field scanning optical microscopy, and
heat-assisted magnetic recording, and it is also ideal to enhance
nonlinear optical effects.