介电常数虚部对Mie粒子保守力非保守力的影响  

Influence of the Imaginary Part of Permittivity to the Conservative and Non-conservative Forces Exerted on Mie Particles

作　　者：李凯凯 陈君[1] 

机构地区：[1]山西大学理论物理研究所,山西太原030006

出　　处：《山西大学学报（自然科学版）》2017年第4期771-780,共10页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(11404201;11674204);山西省科技厅基金(2014011008-1)

摘　　要：通过基于快速傅里叶变换和Mie理论的数值模拟以及基于多极展开理论的解析分析,研究了影响光力的介电常数虚部对介质及金属材料微粒z方向保守力、非保守力的影响。结果表明对于介质材料以及金属材料,解析结果和数值结果可以很好地保持一致。非保守力z分量的最大值总是出现在场强最大的位置,而保守力z分量的最大值则总是出现在场强最大值的两边,并且这两种力均在微粒远离场强最大处时迅速衰减。但是保守力和非保守力的具体变化趋势对于介质和金属材料却有不同。保守力和非保守力随介电常数虚部变化的根本在于材料性质对极化率以及两种力影响的不同。文章对保守力非保守力的研究,有利于对微粒更加精准、自由地操控。Based on fast Fourier transform, Mie theory and multipole expansion, this paper numerically and analytically investigate the influence of the imaginary part of permittivity, which is an important quantity for optical force, to the z-component conservative and non-conservative forces exerted on dielectric or metallic Mie particles. The analytical results can match numerical simulations very well for both dielectric and metallic material particles. The maximum values of the z-component non-conservative forces always lie on the position of the maximum electro-magnetic fields, while those of the conservative forces always lie on both sides of the maximum fields, and the two forces both diminish quickly when the particle runs away from the maximum fields. The specific change trends of the conservative and non-conservative force for dielectric and metallic particles are different. The analysis shows the different variation of the conservative and non-conservative force with the imaginary part of permittivity root in the different influence of the various properties of materials to the polarizabilities and the two different kinds of forces. The investigation of conservative and non-conservative forces favors more accurate and freely manipulation on ＇micro-particles.

关 键 词：光力 保守力 非保守力 介电常数虚部 Mie粒子 

分 类 号：O442[理学—电磁学]