Plasmonics, one of the most promising subfields in nano-photonics, has attracted much attention due to the possibility of focusing, guiding and manipulating light on the nanoscale, overcoming the diffraction limit of classical optics.
Surface plasmons, studied in plasmonics, are due to collective oscillations of the electron gas in metals and can exist in the form of propagating surface waves or localized excitations. Noble metals can support surface plasmons within and around the visible spectrum, which allows the surface plasmons to be excited by regular optical sources. However, the practical usability of surface plasmons is significantly reduced by the losses in metallic materials and the short propagating length. Methods of reducing such losses and increasing the propagating length are highly desirable.
In this thesis, surface plasmons are analyzed both theoretically and numerically. A composite material reducing surface plasmon losses and increasing the range of propagation is proposed.
In numerical modeling, absorbing boundary conditions for surface plasmons are proposed and tested; such conditions reduce the size of the computational domain and the computational resources required.