Toward Efficient Optical Trapping of Sub-10-nm Particles with Coaxial Plasmonic Apertures
Toward Efficient Optical Trapping of Sub-10-nm Particles with Coaxial Plasmonic Apertures
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DOI：
10.1021/nl302627c
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发表时间：
2012-11-01
期刊：
影响因子：
10.8
通讯作者：
Dionne, Jennifer A.
中科院分区：
文献类型：
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作者：
Saleh, Amr A. E.;Dionne, Jennifer A.
使用聚焦激光束的光学捕获已经成为生物和物理科学中的强大工具。然而，由于光的衍射极限和纳米级捕获所需的高功率水平，将这种技术扩展到纳米级物体具有挑战性。在本文中，我们提出了等离子体同轴孔作为低功率光陷阱的纳米样品。用线偏振平面波照射同轴小孔，产生一个双光阱。捕获直径小于10 nm的电介质颗粒，同时保持捕获功率水平低于20 mW。通过逐渐减小同轴电介质通道的厚度，可以将捕获扩展到亚2纳米颗粒。所提出的结构可以实现从单个蛋白质到以前无法达到的大小的小分子的电介质颗粒的光学捕获和操纵。
Optical trapping using focused laser beams has emerged as a powerful tool in the biological and physical sciences. However, scaling this technique to nanosized objects challenging due to the diffraction limit of light and the high power levels required for nanoscale trapping. In this paper, we propose plasmonic coaxial apertures as low power optical traps for nanosized specimens. The illumination of a coaxial aperture with a linearly polarized plane wave generates a dual optical trapping potential well We theoretically show that this potential can stably. trap dielectric particles smaller than 10 nm in diameter while keeping the trapping power level below 20 mW. By tapering the thickness of the coaxial dielectric channel, trapping can be extended to sub-2-nm particles. The proposed structures may enable optical trapping and manipulation of dielectric particles ranging from single proteins to small molecules with sizes previously inaccessible.