Study On Fano Scattering Characteristics Of Topological Nanoparticles

In this thesis,the light scattering characteristics of topological core-shell cylinders and eccentric topological nanoparticles are studied.Based on the extension of Mie theory and finite element method,this paper theoretically studies the far-field scattering and near-field energy flow distribution of cylinders with topological dielectric shell plasma core structure,and analyzes the scattering characteristics with that of topological plasma core dielectric shell.By constructing eccentric geometry and based on multistage expansion theory,the far-field scattering of eccentric topological cylinder and eccentric topological sphere is discussed in this paper.The main contents are as follows:1.Light scattering characteristics of topological core-shell cylinder near Fano resonanceTopological magnetoelectric effect(TME)is a special response of topological nanoparticles in scattering.This effect can make electromagnetic fields interact with each other,which can lead to many interesting optical phenomena.In this paper,the cylinder of topological dielectric shell plasma core structure is used for research and discussion.It is found that the interference generated by TME effect will have observable displacement in far-field scattering.The existence and influence of TME effect are confirmed by the distribution of near-field electromagnetic field.This makes Fano resonance adjustable.In addition,through the comparative analysis of topological plasma core dielectric shell cylinder,it is confirmed that it is more sensitive to topological magnetoelectric effect.These results will provide a new method for detecting the electromagnetic scattering characteristics of topological nanoparticles in engineering.2.Light Scattering characteristics of eccentric topological nanoparticlesSpecial geometry scatterers can often show interesting scattering characteristics in optics.In this paper,by constructing an eccentric topological cylinder,it is found that its forward scattering cross section is robust.Under the action of TME effect,the forward far-field scattering does not change with the direction of eccentricity.In the near field,the electromagnetic field of eccentric topological cylinder is enhanced.In addition,this paper studies the eccentric topological spherical particles based on the multistage expansion theory,which proves the feasibility of the research method,and finds that the eccentric spherical particles can change the far-field scattering characteristics by adjusting the direction and distance of eccentricity under the TME effect.The research results of this paper will provide theoretical support for the later research of complex geometric scatterers,and provide a new direction for the design of optical devices.