Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London, UK.
ACS Nano. 2009 Oct 27;3(10):3077-84. doi: 10.1021/nn900818n.
We analyze the rotational dynamics of light driven nanorotors, made of nanotube bundles and gold nanorods aggregates, with nonsymmetric shapes, trapped in optical tweezers. We identify two different regimes depending on dimensions and optical properties of the nanostructures. These correspond to alignment with either the laser propagation axis or the dominant polarization direction, or rotational motions caused by either unbalanced radiation pressure or polarization torque. By analyzing the motion correlations of the trapped nanostructures, we measure with high accuracy both the optical trapping parameters and the rotation frequency induced by the radiation pressure. Our results pave the way to improved all-optical detection, control over rotating nanomachines, and rotation detection in nano-optomechanics.
我们分析了在光镊中捕获的、由非对称形状的碳纳米管束和金纳米棒聚集体组成的光驱动纳米转子的旋转动力学。我们根据纳米结构的尺寸和光学特性确定了两种不同的状态。这些状态对应于与激光传播轴或主要偏振方向对齐的状态，或者由不平衡的光辐射压力或偏振扭矩引起的旋转运动。通过分析被捕获纳米结构的运动相关性，我们以高精度测量了光镊的参数和由辐射压力引起的旋转频率。我们的研究结果为改进全光检测、对旋转纳米机器的控制以及纳米光机械学中的旋转检测铺平了道路。
