Laser trapping and micro-manipulation using optical vortices
Laser trapping and micro-manipulation using optical vortices
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DOI：
10.1016/j.mee.2004.12.017
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发表时间：
2005-03-01
影响因子：
2.3
通讯作者：
Di Fabrizio, E
中科院分区：
文献类型：
--
作者：
Cojoc, D;Garbin, V;Di Fabrizio, E
这项工作的目的是研究拉盖尔高斯 (LG) 光束（通常称为光学涡旋）对于无法使用高斯光束进行的激光捕获和操纵实验的有用性。拉盖尔高斯光束表现出“甜甜圈”状的横向强度分布并携带轨道角动量（OAM），极大地扩展了激光镊子的能力。这些光束可以通过利用特性设计的衍射光学元件（DOE）转换由普通激光源产生的高斯光束来获得。我们提出了两种捕获系统，第一个基于幅度 DOE，第二个基于相位 DOE。在这两种情况下，DOE 都是在液晶显示器上实现的。演示了在“环形”轮廓上捕获小的介电高折射率颗粒。还观察到 OAM 转移到被捕获的粒子，导致旋转。此外，会被传统高斯光束拒绝的低折射率粒子被捕获在甜甜圈的零强度区域中。 (c) 2004 Elsevier B.V. 保留所有权利。
The aim of this work is to investigate the usefulness of the Laguerre-Gaussian (LG) beams, often referred to as optical vortices, for laser trapping and manipulation experiments that cannot be performed using Gaussian beams. Laguerre-Gaussian beams, exhibiting "doughnut"-like transversal intensity distributions and carrying orbital angular momentum (OAM), greatly extended the capabilities of laser tweezers. These beams can be obtained by converting the Gaussian beam generated by a common laser source, by means of property designed diffractive optical elements (DOEs). We present two trapping systems, the first one based on amplitude DOEs, the second one based on phase DOEs. In both cases the DOE is implemented on a liquid crystal display. Trapping of small dielectric high-index particles on the "doughnut" profile is demonstrated. OAM transfer to trapped particles, that are caused to rotate, is observed as well. Moreover, low-index particles, that would be rejected by a conventional Gaussian beam, are trapped in the zero intensity region of the doughnut. (c) 2004 Elsevier B.V. All rights reserved.