Bautista Godofredo, Kakko Joona-Pekko, Dhaka Veer, Zang Xiaorun, Karvonen Lasse, Jiang Hua, Kauppinen Esko, Lipsanen Harri, Kauranen Martti
Opt Express. 2017 May 29;25(11):12463-12468. doi: 10.1364/OE.25.012463.
The three-dimensional (3D) optical fields that arise from the focusing of cylindrical vector beams (CVB) with radial and azimuthal polarizations provide new sources of contrast for optical microscopy of nano-objects. So far, these demonstrations have been restricted to two-dimensional transversal scanning, i.e., along the focal plane of interest, or use of point-like objects, i.e., single molecules and nanoparticles. Here, we demonstrate the first application of CVBs for 3D imaging of 3D nano-objects. This technique is done by acquiring 3D image scans of the second-harmonic generation signal from vertically-aligned semiconductor nanowires, whose second-order response is primarily driven by the longitudinal electric field, i.e., the field component along the nanowire axis. Our technique provides a new way to study individual nano-objects in three dimensions through the unique combination of nonlinear microscopy and CVBs.
由具有径向和方位角偏振的圆柱矢量光束（CVB）聚焦产生的三维（3D）光场为纳米物体的光学显微镜提供了新的对比度来源。到目前为止，这些演示仅限于二维横向扫描，即沿着感兴趣的焦平面，或者使用点状物体，即单分子和纳米颗粒。在这里，我们展示了CVB在三维纳米物体三维成像中的首次应用。该技术是通过获取垂直排列的半导体纳米线的二次谐波产生信号的三维图像扫描来实现的，其二次响应主要由纵向电场驱动，即沿纳米线轴的场分量。我们的技术通过非线性显微镜和CVB的独特组合，提供了一种在三维空间中研究单个纳米物体的新方法。
