The Research And Application Of Multipolar Expansion Algorithm For Light Field To Regulate The Force Exerted On Nanoparticles

The scattering of light by particles is a common optical phenomenon in nature,and it is also one of the main contents that constitute the interaction between light and matter.Not only can people use the scattering of incident light to control the propagation mode of light,but also manipulate the dynamics of particles by the energy transfer between light and particles during the scattering of light.For scattering of light,the Multipolar Expansion based on Mie theory is a classical algorithm to describe the scattering of light by particles.It can be used to solve the analytical solution of Maxwell's equations in the case of light scattering and to quantitatively describe the optical properties,such as the scattering,extinction,absorption of light and so on.In recent years,with the continuous improvement of Mie's algorithm,the use of Multipolar Expansion based on Mie theory to study the dynamic process of particles under the interaction of plane electromagnetic waves has become a research hotspot in the field of nanophotonic.This paper uses MATLAB software to program the algorithm of the optical force of the nanoparticle based on the Multipolar Expansion of Mie theory,and develops the software to calculate the force of nanoparticle under the action of plane waves.The research results will provide theoretical basis and experimental reference for studying the interaction between nanoparticles and light,and the research contents mainly include the following parts:(1)The optimization of the Multipolar Expansion algorithm based on Mie theory.We use the improved backward recursive algorithm to solve the Mie coefficient and calculate the scattering,extinction and absorption efficiency of the particles.The results show that compared to other algorithms,the Multipolar Expansion method based on Mie theory can obtain accurate numerical solutions,and its computational efficiency can be greatly improved;(2)An algorithm based on Multipolar Expansion of the Mie theory is developed to analyze the optical force of nanoparticle under the action of plane waves.Compared to other relevant common algorithms,it can not only improve the computational efficiency,but also deeply study the effects of various resonance modes on the force of particles in the process of resonance scattering;(3)MATLAB was used to develop an optical simulation software that can be used to calculate the scattering,absorption,extinction of light by particles and the optical force under the action of plane waves;(4)The Multipolar Expansion algorithm based on Mie theory is used to study the optical force of gold core silicon shell nanoparticles under plane electromagnetic waves.The results manifest that the degree of coherence of the particle resonance modes can be dynamically manipulated by changing the size of the gold core,thereby effectively modulating the size of the optical force of the nanoparticle;...