Simulation study of near-field enhancement on an Ag nanoparticle dimer system in a laser-induced nanowelding process

Abstract

To analysis the mechanism of laser-induced nanowelding, the near-field enhancement of an Ag nanoparticle dimer system which is irradiated by laser was calculated based on a finite element method (FEM) in this paper. Meanwhile, we investigated a number of parameters which have a tremendous impact on enhancement factors, such as the gap between the nanoparticles and the polarization and wavelength of the laser. The results indicate that narrow gap between Ag nanoparticles is beneficial for generation of field enhancement. Only the vector component of initial electric field in laser along the dimer axis has an effect on the electric field enhancement. The system has regular responses to different wavelengths. There are three peak points at 370,470,500 nm especially. These results will be guidance to the experimental research in the future.