Localized Surface Plasmons

As particle plasmons or localized surface plasmons are called immovable surface plasmons, ie not propagating field peaks of small metal particles such as gold or silver. It is thus a special plasmon. For sufficiently small particle (diameter << wavelength of the incoming electromagnetic radiation, e.g., light) can be regarded as such a vibrating dipole electrostatic approximation. Its dipole moment is:

Here are

• The permittivity of free space
• The permittivity of the surrounding medium
• The permittivity of the metal,
• The radius of the metal sphere.

Since the permittivity of metals very strongly on the wavelength of the electromagnetic oscillation depends ( Drude theory ), and the magnitude of the polarization is wavelength dependent. Incident light is therefore absorbed to different degrees and for different frequencies scattered by the dipole. This effect is used for lead glass, which adopt these different colors.