Nanometric optical tweezers based on nanostructured substrates
Nanometric optical tweezers based on nanostructured substrates
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DOI：
10.1038/nphoton.2008.78
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发表时间：
2008-06-01
期刊：
影响因子：
35
通讯作者：
Zhang, Y.
中科院分区：
文献类型：
--
作者：
Grigorenko, A. N.;Roberts, N. W.;Zhang, Y.
以纳米精度控制介观物体的位置的能力对于纳米科学的快速发展是重要的。实现这种控制的最有前途的工具之一是光镊，它可以捕获激光束焦点附近的物体。然而，传统镊子的缺点包括被捕获的纳米物体的衍射受限和显著的布朗运动的捕获体积。在这里，我们报告的第一个实验实现的三维纳米光镊是基于纳米结构的基板。使用电磁耦合对金纳米点在标准的光镊设置，我们创建了一个阵列的亚波长等离子体光学陷阱，提供了显着增加的捕获效率。纳米点光学近场减少了超过衍射极限的捕获体积，并且与在相同捕获条件下操作的常规镊子相比，将捕获的纳米颗粒的布朗运动猝灭几乎一个数量级。我们的镊子以显著更小的激光功率实现了对实体的纳米级控制，并为脆弱生物物体的纳米操纵开辟了新的途径。
The ability to control the position of a mesoscopic object with nanometric precision is important for the rapid progress of nanoscience. One of the most promising tools to achieve such control is optical tweezers, which trap objects near the focus of a laser beam. However, the drawbacks of conventional tweezers include a trapping volume that is diffraction-limited and significant brownian motion of trapped nanoobjects. Here, we report the first experimental realization of three-dimensional nanometric optical tweezers that are based on nanostructured substrates. Using electromagnetically coupled pairs of gold nanodots in a standard optical tweezers set-up, we create an array of subwavelength plasmonic optical traps that offer a significant increase in trapping efficiency. The nanodot optical near-fields reduce the trapping volume beyond the diffraction limit and quench brownian motion of the trapped nanoparticles by almost an order of magnitude as compared to conventional tweezers operating under the same trapping conditions. Our tweezers achieve nanoscale control of entities at significantly smaller laser powers and open new avenues for nanomanipulation of fragile biological objects.