Semiconductor nanowires are promising building blocks for next-generation photonics. Indirect proofs of large absorption cross sections have been reported in nanostructures with subwavelength diameters, an effect that is even more prominent in vertically standing nanowires. In this work we provide a three-dimensional map of the light around vertical GaAs nanowires standing on a substrate by using fluorescence confocal microscopy, where the strong long-range disruption of the light path along the nanowire is illustrated. We find that the actual long-distance perturbation is much larger in size than calculated extinction cross sections. While the size of the perturbation remains similar, the intensity of the interaction changes dramatically over the visible spectrum. Numerical simulations allow us to distinguish the effects of scattering and absorption in the nanowire leading to these phenomena. This work provides a visual understanding of light absorption in semiconductor nanowire structures, which is of high interest for solar energy conversion applications.

中文翻译：

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借助3D荧光共聚焦显微镜对直立的纳米线中的光吸收和波导进行视觉理解

半导体纳米线有望成为下一代光子学的基础。在具有亚波长直径的纳米结构中，已经间接证明了大的吸收截面，这种作用在垂直站立的纳米线中更为明显。在这项工作中，我们通过使用荧光共聚焦显微镜提供了竖立在衬底上的垂直GaAs纳米线周围的光的三维图，其中示出了沿纳米线的光路的强远距离扰动。我们发现，实际的远距离扰动的大小要比计算出的消光横截面大得多。尽管扰动的大小保持相似，但相互作用的强度在可见光谱范围内发生了巨大变化。数值模拟使我们能够区分导致这些现象的纳米线中的散射和吸收效应。这项工作提供了对半导体纳米线结构中光吸收的直观了解，这对于太阳能转换应用非常重要。