Perpustakaan Digital ITB

Nowadays, plasmon has been a widely discussed topic in nanophotonics field due to its properties, which are the confinement and localization of electromagnetic field. Plasmon is collective oscillation of electrons in conducting material. In nanoparticles, electron oscillation is localized therefore it is known as localized surface plasmon resonance. It is well known that resonance frequency of localized plasmon is determined from the graph of scattering cross section and absorption cross section vs energy. However, these methods have high tendency of human error. In addition, there is ambiguity due to the possibility of different peak frequencies in the absorption and scattering cross section graphs. Thus, a more fundamental method to determine the plasmon resonance frequency is necessary, that is by getting back the very basic definition of natural frequency of plasmon. The definition of plasmon natural frequency is the oscillation modes of electron in absence of external electromagnetic field. The problem encountered here is an eigenvalue problem similar to the potential well problem in Quantum Physics. In this thesis, the transcendental equation to get the resonance frequency of a nanosphere is derived by means of applying boundary condition to the Mie Theory.