Hameed Nyha, Nouho Ali Ali, Baida Fadi I
Département d'Optique P.M. Duffieux, Institut FEMTO-ST, UMR 6174 CNRS, Université Bourgogne Franche-Comté, 15B Avenue des Montboucons, 25030, Besançon Cedex, France.
Al Muthanna University, College of Science, Department of Physics, Al Muthanna, Iraq.
Sci Rep. 2017 Oct 9;7(1):12806. doi: 10.1038/s41598-017-13201-w.
In this paper, we propose and numerically simulate a novel optical trapping process based on the enhancement and the confinement of both magnetic and electric near-fields by using gold Diabolo Antenna (DA). The later was recently proposed to generate huge magnetic near-field when illuminated by linearly polarized wave along its axis. Numerical 3D - FDTD simulation results demonstrate the high confinement of the electromagnetic field in the vicinity of the DA. This enhancement is then exploited for the trapping of nano-particles (NP) as small as 30 nm radius. Results show that the trapping process greatly depends on the particle dimensions and that three different regimes of, trapping at contact, trapping without contact, or pushing can be achieved within the same DA. This doubly resonant structure opens the way to the design of a novel generation of efficient optical nano-tweezers that allow manipulation of nano-particles by simply changing the operation wavelength.
在本文中，我们提出并通过数值模拟了一种基于利用金双锥体天线（DA）增强和限制磁近场与电近场的新型光阱捕获过程。最近有人提出，当沿其轴用线偏振波照射时，后者会产生巨大的磁近场。三维有限时域差分（3D - FDTD）数值模拟结果表明，在双锥体天线附近电磁场具有高度限制。然后利用这种增强来捕获半径小至30nm的纳米颗粒（NP）。结果表明，捕获过程很大程度上取决于颗粒尺寸，并且在同一个双锥体天线内可以实现三种不同的状态：接触捕获、非接触捕获或推动。这种双共振结构为新一代高效光学镊子的设计开辟了道路，这种光学镊子只需改变操作波长就能实现对纳米颗粒的操控。
