ABSTRACT

With the advancement in nanotechnology, enormous interests in nanostructures are growing in fields such as engineering, biotechnology, and medicine. When a light is incident on a metallic nanoparticle localized surface plasmons (LSPs) are generated surrounding the nanoparticle. LSPs are the collective oscillations of free conduction electrons excited by incident light or electrons. LSPs lead to the highly enhanced field at the vicinity of nanoparticles. The highly enhanced field is dependent on physical properties of nanoparticles and material surrounding nanoparticles. The enhancement of the field is exploited for many applications from curing of cancer and tumor cells to the production of nano-devices. This can be done when the localized field goes beyond the ablation threshold of material surrounding nanostructure. The accumulation of the enhanced field is dependent on optical properties of the nanoparticles and substrate together wit h the physical structure of the nanoparticles. The physical shape leads to the·excitation of different resonances modes in metallic nanoparticles when illuminated with the light. The detailed investigation of the excitation of resonances modes in different shapes of nanoparticles is still lacking.
This work aims to theoretically investigate the excitation of LSPs on different shapes of nanoparticles i.e. triangular nanoparticles, nanodisks, and spherical nanoparticles. The enhancement of electric field of the mentioned nanoparticles is studied and compared. Furthermore, the cause of the field enhancement is established. Th is study will help in understanding the ablation process of substrate in the technology applications.