Stable Fano-like plasmonic resonance: its impact on the reversal of far-and near-field optical binding force

查看全文 作　　者：Hamim Mahmud [1,2]Rivy;M R C [1,3]Mahdy;Nabila [1]Masud;Ziaur Rahman [1]Jony;Saikat Chandra [1]Das 机构地区：[1]Department of Electrical&Computer Engineering,North South University,Bashundhara,Dhaka,1229,Bangladesh;[2]School of Electrical and Electronic Engineering,Nanyang Technological University,50 Nanyang Ave,639798 Singapore;[3]Pi Labs Bangladesh LTD,ARA Bhaban,39,Kazi Nazrul Islam Avenue,Kawran Bazar,Dhaka 1215,Bangladesh 出　　处：《Communications in Theoretical Physics》索引2020年第72卷第4期,共17页 基　　金：the support of the internal grant of North South University 2018–19 and 2019–20(approved by the members of BOT,North South University,Bangladesh)along with the support of a TWAS international grant 2018–19(18-121 RG/PHYS/AS_I). 摘　　要：Even for a 100 nm interparticle distance or a small change in particle shape,optical Fano-like plasmonic resonance mode usually vanishes completely.It would be remarkable if stable Fano-like resonance could somehow be achieved in distinctly shaped nanoparticles for more than 1μm interparticle distance,which corresponds to the far electromagnetic field region.If such far-field Fano-like plasmonic resonance can be achieved,controlling the reversal of the far-field binding force can be attained,like the currently reported reversals for near-field cases.In this work,we have proposed an optical set-up to achieve such a robust and stable Fano-like plasmonic resonance,and comparatively studied its remarkable impact on controlling the reversal of near-and far-field optical binding forces.In our proposed set-up,the distinctly shaped plasmonic tetramers are half immersed(i.e.air-benzene)in an inhomogeneous dielectric interface and illuminated by?circular?polarized light.We have demonstrated significant differences between near-and far-field optical binding forces along with the Lorentz force field,which partially depends on the object’s shape.A clear connection is shown between the far-field binding force and the resonant modes,along with a generic mechanism to achieve controllable Fano-like plasmonic resonance and the reversal of the optical binding force in both far-and near-field configurations. 关 键 词：Fano resonance OPTICAL binding FORCE LORENTZ FORCE plasmonic TETRAMER