Optical Trapping of Quantum Dots Based on Gap-Mode-Excitation of Localized Surface Plasmon
Optical Trapping of Quantum Dots Based on Gap-Mode-Excitation of Localized Surface Plasmon
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DOI：
10.1021/jz100659x
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发表时间：
2010-08-05
影响因子：
5.7
通讯作者：
Ishihara, Hajime
中科院分区：
文献类型：
--
作者：
Tsuboi, Yasuyuki;Shoji, Tatsuya;Ishihara, Hajime
基于表面等离子体激元的纳米/微米粒子的光捕获是等离子体学和纳米光子学领域的一个热点。到目前为止，通过间隙模式等离子体激元进行这种捕获的实验证明仅限于少数报道，其中亚微米聚合物珠被MW/cm（2）的强辐射捕获，满足U > kT的能量条件。（U是陷阱的势能，kT是平均热背景能量。）我们展示了发光量子点（Q点，直径>= 10 nm）的基于等离子体激元的光学捕获，具有非常弱的照射（0.5-10 kW/cm（2））。最重要的发现是，即使在U < kT的能量条件下，也可以通过发光检测清楚地观察到Q点捕获，在此基础上，我们提出了一个新的概念，这是纳米间隙处基于等离子体的捕获所特有的。
One of the recent hot topics in the fields of plasmonics and related nanophotonics is optical trapping of nano/microparticles based on surface plasmon. Experimental demonstration of such trapping by gap-mode plasmon has hitherto been limited so far to a few reports in which submicrometer polymer beads were trapped with intense irradiation at MW/cm(2), satisfying an energetic condition of U > kT. (U is the potential energy of the trap and kT is an averaged thermal background energy.) We demonstrate plasmon-based optical trapping of a luminescent quantum dot (Q dot, diameter >= 10 nm) with a very weak irradiation (0.5-10 kW/cm(2)). The most important discovery is that the Q dot trapping was clearly observed through luminescence detection even under an energetic condition of U < kT, on the basis of which we propose a novel concept that is peculiar to plasmon-based trapping at a nanogap.