Studies On Surface Plasmon Of Metallic Nanocubes And The Nanostructures Of TiN

The optical properties of metallic nanostructures and their applications in surface enhanced spectroscopy have received much attention in nanoscience and nanotechnology.In recent years,the surface plasmon optical properties have been widely used in physics,chemistry,surface science,energy and material science.In this thesis,we have studied the optical properties of metallic nanocubes dimer coupling with metal substrate and the plasmon properties of TiN based on FDTD calculations.The thesis is divided into four chapters.In the first chapter,the purpose and tasks of this study were proposed after reviewing the theory and extended applications of surface palsmons(SPs),the main features and the progress of studies on nanocubes structures and the plasmon properties on TiN.The second chapter is mainly on the calculation method of three-dimensional finite-difference time-domain(3D-FDTD).In the third chapter,we theoretically studied the plasmon modes competition and synergistic effects in multipole coupling system of metallic nanocubes dimer over the metallic substrate.In the fourth chapter,we theoretically studied the plasmon properties of different nanostructures of TiN,and provided the possibility of TiN applied in nanoscience.The innovative points and key research results are as follows:1.Using the three-dimensional finite-difference time-domain(3D-FDTD)method,we investigated near field coupling effects of a face-to-face metallic nanocubes dimer over a metal substrate with small separation distance.Compared to a nanocubes dimer or the coupling system of one nanocube over a metal substrate,we found that when the nanocubes dimer coupling with metal substrate,the system tightly confine the light within the gap,and resulting in strongly hybridized modes in which the competition and synergistic effects between the two dipole modes in different area are special.Each of the resonance modes is identified by the surface charge distribution.With the plasmon competitive and synergistic effects,this coupling system shows potentially promising applications such as their relatively narrow line width and giant field enhancement from the synergistic effects allow highly sensitive sensing of refractive index and the figure of merit(FoM)for sensing is predicted to be over 30.2.The applications of TiN in plasmon optics.TiN is the non-metal material,but as the optical constant of it is similar to the traditional plasmonic materials like Au or Ag,it can be used in plasmonics.Differ from the traditional plasmon metals,TiN has lower absorption loss and is stable without oxidation.Research on various nanostructures of TiN for the plasmon properties,we discovered that the TiN was good material used in plasmonics,and it would exhibit the similar properties like Au or Ag.This study can make the materials of plasmonics in the research extend to TiN.