Simulation Calculation Of Interaction Between Elliptically Radial Polarized Beams And Metal Elliptical Disk

With the in-depth study of the interaction between light and matter,people are more and more aware of the importance of cylindrical vector beams.Compared to traditional scalar beams,vector beams have a non-uniform distribution in space.This property is particularly prominent when interacting with metal particles.Local surface plasmons generated by vector beams on metal particles have been successfully applied in the fields of optical microscopy imaging,biosensing technologies,micro/nano?fabrication,and optical manipulation.With great success,the vector beam has become a research focus in the past two decades.We recently independently found an elliptically radial polarized beams similar to a radially polarized beam.The electric field vector at any point in the cross section of vertical beam propagation is curved along the direction of the hyperbola in the elliptic coordinate system.We can freely adjust the ellipticity of elliptically radial polarized beams,which is equivalent to providing an additional degree of freedom to the beam,helping to control the characteristics of the electric field at the focal point and allowing the field distribution at the focal point to match the specific application.In this paper,the vector distribution of elliptically radial polarized beams is derived from the formula,and then a special vortex half-wave retarders is designed to generate it,and the optical and forces effect between elliptical radial polarized beams and oval metal nanodisc are also analyzed.In the first chapter,this article briefly introduces the basic concept of space vector beam,then introduces the application of vector beam in optical tweezers and surface plasmons,and finally introduces the innovation of this article.In the second chapter,we focus on the astigmatic elliptical beam and the eigenmode elliptical beam and their generation methods.Among them,the electric field formula and derivation process of various elliptical beams are analyzed in detail,and then their respective optical properties are introduced.In the third chapter,the principle of a half-wave retarder is briefly introduced first from the phase delay of the wave plates,and a special vortex half-wave retarders is designed by analyzing the vector distribution of elliptically radial polarized beams.Then introduced the finite element method(FEM)used to solve the physical model and the multiphysics simulation software COMSOL.A linearly polarized with elliptical radial symmetry beam similar to elliptically radial polarized beams is also introduced.Finally,a vortex half-wave plate is used to simulate elliptically radial polarized beams and elliptically angular polarized beams in COMSOL.In the Chapter 4,we focus on the application of elliptically radial polarized beams.In order to verify the reliability of the vortex half-wave retarders method,we use the same method to generate traditional radially polarized beam and successfully use it on metal nanodisc The Breathing mode is excited.Then,the elliptically radial polarized beams was used to interact with the oval metal nanodisc to calculate the extinction spectrum and resonance mode of the disk surface.Finally,the beam is rotated to analyze the changes of the optical forces and torques received by the elliptical disc.The last chapter summarizes the main work of this paper,and analyzes the optical characteristics of elliptically radial polarized beams and its potential application value in various aspects.