Numerical Simulation on Electromagnetic Field Distribution of Multiple Metallic Nanoparticles

In this thesis, we propose a novel simplified boundary integral-equation (SBIE) method for investigating the scattering, absorption and field localization properties of multiple gold nanospheres (NSs) arbitrarily distributed in a homogeneous space. By comparing with the commercial software COMSOL, simulation results of the near-field patterns confirm the validity of the SBIE method. Meantime, we find that the SBIE is much more efficient than COMSOL for treating a large number of nanoparticles. Then, we arrange the gold NSs as one-, two- and three-dimensional arrays to further test our program. It is found that the localized surface plasmon (LSP) resonance can be enhanced and widely broadened to the near infrared (NIR) range. We also find that the LSP resonance can be significantly tuned by varying the constituent nanoparticle geometries, interparticle separation, total NS number, dielectric environment, arrangement of distributions, etc. Note that, the SBIE is more rigorous than the conventional coupled-dipole approximation (CDA) model and has the potential to cope with scattering problems for multiple objects with different sizes, shapes and materials. In other words, this versatile SBIE method is helpful for the design of a variety of novel plasmonic devices.