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.

KEYWORDS:

• Near-field enhancement
• laser-induced nanowelding
• nanoparticle dimer

Funding

This project was supported by the National Key Research and Development Program of China (2017YFB1104900), National Natural Science Foundation of China (51505371, 11372264), Hong Kong Scholars Program (XJ2015038), a research grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (CityU 114013), Young Elite Scientists Sponsorship program by CAST (2016QNRC001), Natural Science Basic Research Plan in Shaanxi Province of China (2017JM5015), State Key Laboratory of Advanced Brazing Filler Metals & Technology, Zhengzhou Research Institute of Mechanical Engineering (SKLABFMT-2016-05) and Open Research Foundation of State Key Lab. of Digital Manufacturing Equipment and Technology in Huazhong University of Science and Technology (DMETKF2016007). All the authors gratefully acknowledge their support.