Study On Resonant Effect Of High - Order Surface Quasicrystals On The Structure Of Precious Metals

The Surface Plasmon is a kind of electric magnetic wave which is propagating along the boundary of the metal and dielectric. It is generated by the coupling of the incident light and the free electrons at the surface of the metal. The theory of it has gained more and more attentions from researchers and scholars all around the world since it has been proposed last century. The plasmons on metal nanoparticles will oscillation by the driven of the incident light. When the frequencies of the plasmons of the metal nanoparticle and the incident light are the same, the surface plasmon resonance is formed. Size, shape of metal nanoparticle and its configuration has many influences on the surface plasmonic features of the nanostructure.By manipulating the size, shape and relative position of nanoparticles can design different kinds of surface plasmonic devices. These devices can break the limitation of diffraction and manipulate light in much smaller scale than normal optical devices. As a result, surface plasmonic devices showed huge promising usage in many fields such as surface enhanced Raman scattering (SERS) spectra, plasmonic light waveguide, solar cells, and biosensors. With the developing of the theory and fabrication technology, the exploring of the plasmonic features of metal nanostructure has been a rather popular topic for researchers. This work has been formed into a new branch of science which is called as Plasmonics.This paper is based on the current study of surface plasmonics, and proposed a new way to generate complex high order plasmonic resonance by coupling basic nanostructures. This paper is divided into three main sections. The first section introduced several popular numerical simulation methods and the simulation software used. The second section introduced the plasmonic features of several basic nanostructure and nano dimers. The third section introduced the square ring-disk (SRD) nanostructure and analyzed its plasmonic features. Which is mainly discussed in this part is the interference of the plasmonic features by breaking its symmetry. Main content of each part of the article are described as follows.In the first part, three popular calculation methods are introduced. Those are finite difference time domain (FDTD) methods, discrete dipole approximation (DDA) method, and the finite element method (FEM). The following part introduced the simulation software used in this paper which is COMSOL Multiphysics. In this part, several key points contains the way to set up ports, boundary conditions, initial value values and calculation of S-parameters are explained.In the second part, plasmonic features of several basic nanostructures are showed. After that, discussions about the dimers are followed and then introduced a method to generate the dark plasmonic resonance mode.In the third part, A square ring-disk(SRD) nanostructure is proposed. By changing the relative position of the square ring and the square plate we can manipulate the resonance mode and the fix the missing resonance order which disappeared in the symmetry SRD.