Plasmon-assisted optical trapping and anti-trapping  

作　　者：Aliaksandra Ivinskaya Mihail I Petrov Andrey A Bogdanov Ivan Shishkin Pavel Ginzburg Alexander S Shalin 

机构地区：[1]Department of Nanophotonics and Metamaterials,ITMO University,Birzhevaja Line,14,199034 St Petersburg,Russia [2]School of Electrical Engineering,Tel Aviv University,Ramat Aviv,Tel Aviv 69978,Israel [3]Kotel’nikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences(Ulyanovsk branch),Goncharova Street 48/2,432071 Ulyanovsk,Russia [4]Ulyanovsk State University,Lev Tolstoy Street 42,432017 Ulyanovsk,Russia

出　　处：《Light(Science & Applications)》2016年第1期52-57,共6页光（科学与应用)（英文版）

基　　金：supported in part by the Government of the Russian Federation(No 074-U01);the Russian Fund for Basic Research within the Project No 15-02-01344,16-52-00112,16-32-60167,17-02-01058 and 17-02-01032;supported by the Russian Science Foundation(No 14-12-01227);the support of the President of Russian Federation in the frame of Scholarship SP-4248.2016.1;support of Ministry of Education and Science of the Russian Federation(GOSZADANIE);BAZIS Fund;the RFBR(16-37-60064)and the President of Russian Federation(grantМК-6462.2016.2)for the valuable support;support from TAU rector grant and German-Israeli foundation(No 2339).

摘　　要：The ability to manipulate small objects with focused laser beams has opened a venue for investigating dynamical phenomena relevant to both fundamental and applied science.Nanophotonic and plasmonic structures enable superior performance in optical trapping via highly confined near-fields.In this case,the interplay between the excitation field,re-scattered fields and the eigenmodes of a structure can lead to remarkable effects;one such effect,as reported here,is particle trapping by laser light in a vicinity of metal surface.Surface plasmon excitation at the metal substrate plays a key role in tailoring the optical forces acting on a nearby particle.Depending on whether the illuminating Gaussian beam is focused above or below the metal-dielectric interface,an order-of-magnitude enhancement or reduction of the trap stiffness is achieved compared with that of standard glass substrates.Furthermore,a novel plasmon-assisted anti-trapping effect(particle repulsion from the beam axis)is predicted and studied.A highly accurate particle sorting scheme based on the new anti-trapping effect is analyzed.The ability to distinguish and configure various electromagnetic channels through the developed analytical theory provides guidelines for designing auxiliary nanostructures and achieving ultimate control over mechanical motion at the microand nano-scales.

关 键 词：Gaussian beam Green’s function optical forces optical tweezers surface plasmon 

分 类 号：TN2[电子电信—物理电子学]