Numerical Study Of Nano Plasma Filter Based On Metal-Insulator-Mental Waveguide

Surface Plasmon Polaritons(SPPs)is a collective oscillating reaction of electrons at the interface of metal and medium,and this oscillation is transmitted along the interface as a dense wave.The important characteristic of SPPs is that it can break the limit of diffraction,so that the light can be bound in the size of sub-wavelength.Therefore,SPPs can be made into highly integrated nano devices to replace the existing electronic components,so as a nano integrated components is one of the important application fields of SPPs.Metal-Insulator-Metal(MIM)structures are the most widely used SPPs waveguides.Using MIM waveguides,researchers have designed and researched a variety of optical devices based on SPPs,such as lasers,optical switches,filters,etc.This paper mainly focuses on the research of nano-plasma filter based on MIM waveguide.The main research contents of this paper are as follows.Firstly,this paper discusses the background and significance of the research,and introduces the current research status of SPPs.After that,the related theories of surface plasmons and MIM waveguides are briefly introduced,the Drude model of metal dispersion is discussed in detail with the help of formula derivation.Then this article starts from Maxwell's equations and focuses on the dispersion relationship of SPPs,and an important conclusion is obtained:there is no TE mode at the interface of medium,that is,only the TM mode exists on the surface plasmon.At the same time,the theoretical knowledge about the excitation mode of SPPs and the classification of waveguide of SPPs and optical resonator are introduced.Secondly,this article detailed the commonly used numerical research methods,mainly the Finite Element Method(FEM)and the Finite Difference Time Domain(FDTD).The characteristics and simulation steps of multi physical field simulation software COMSOL Multiphysics based on FEM are introduced.Next,the basic structures of the MIM waveguide filter are studied in this paper.They mainly include single nano-disk resonator,dual-nanometer disk cascade resonator,three-nanometer disk cascade resonator,and additional circular resonator.Through simulation and analysis,the relationship between parameter changes and filter performance is obtained.Based on the analysis of the above basic structures,a new MIM waveguide tunable filter structure is designed and proposed in this paper,the filter characteristics and the influence of the filter structure parameters on the filter performance are also analyzed.The results show that the filter performance is related to the radius of the nano disk,the angle and position of the circular resonator,and the cascade distance of the two nano disk resonators.By adjusting these structural parameters reasonably,a tunable narrow-band nanoplasma filter can be achieved.At last,this paper summarizes the research work,and makes a prospect,so as to find the deficiencies in the research work,and improve the deficiencies.