The James Franck Institute, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, United States.
ACS Nano. 2012 Sep 25;6(9):8144-55. doi: 10.1021/nn302795j. Epub 2012 Aug 17.
We demonstrate controlled trapping and manipulation of single silver (Ag) nanowires in two dimensions at a surface using structured light fields generated with a spatial light modulator. The Ag nanowires are attracted toward the regions of maximal optical intensity along the surface when the trapping laser light is linearly polarized and are repelled toward the minima of optical intensity when the light is circularly polarized. For linearly polarized light, stably trapped nanowires are oriented perpendicular to the polarization direction due to a torque induced by an asymmetrical response of the nanowire to the electric field. The attractive interactions with linearly polarized trapping laser light, which is at 800 nm for all measurements, enable stable trapping and translation of Ag nanowires in the antinodes of optical gratings and in zero-order Bessel beams. Trapped nanowires can be positioned and oriented on a transparent dielectric substrate, making possible the nonmechanical assembly of plasmonic nanostructures for particular functions.
我们展示了使用空间光调制器产生的结构化光场，在二维表面上对单个银（Ag）纳米线进行受控捕获和操纵。当捕获激光光是线性偏振光时，Ag 纳米线会被吸引到表面上的最大光强区域，而当光为圆偏振光时，纳米线会被排斥到光强的最小值处。对于线性偏振光，由于纳米线对电场的不对称响应产生的扭矩，稳定捕获的纳米线会垂直于偏振方向取向。与线性偏振捕获激光光的吸引力相互作用，对于所有测量，该激光光的波长为 800nm，使 Ag 纳米线能够在光学光栅的节点和零阶贝塞尔光束中稳定地捕获和移动。捕获的纳米线可以在透明介电基底上进行定位和定向，从而实现用于特定功能的等离子体纳米结构的非机械组装。
