Extreme-ultraviolet light generation in plasmonic nanostructures
Extreme-ultraviolet light generation in plasmonic nanostructures
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DOI：
10.1038/nphys2590
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发表时间：
2013-03
期刊：
影响因子：
19.6
通讯作者：
M. Sivis;M. Duwe;B. Abel;C. Ropers
中科院分区：
文献类型：
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作者：
M. Sivis;M. Duwe;B. Abel;C. Ropers
光学纳米结构中的强场现象使纳米光子学、等离子体学和阿秒光谱学的集成成为可能。例如，纳米结构增强高谐波产生的报道引发了巨大的兴奋。然而，极紫外和阿秒脉冲产生在纳米尺度上的巨大前景与缺乏成功实现之间的紧张关系越来越大。在这里，我们通过研究暴露在气体中的领结纳米天线的高度非线性光学过程来解决这个问题。我们发现多光子和强场诱导的原子激发和电离导致极紫外荧光，以及纳米结构固有的三次和五次谐波产生。识别原子荧光的强度依赖光谱指纹，我们测量局部等离子体场。虽然在近场确实实现了足以产生高谐波的强度，但发现纳米级的体积阻碍了有效的转换。我们的结果说明了高度非线性等离子体及其扩展到极紫外的机遇和挑战。
Strong-field phenomena in optical nanostructures have enabled the integration of nanophotonics, plasmonics and attosecond spectroscopy. For example, tremendous excitement was sparked by reports of nanostructure-enhanced high-harmonic generation. However, there is growing tension between the great promise held by extreme-ultraviolet and attosecond-pulse generation on the nanoscale, and the lack of successful implementations. Here, we address this problem in a study of highly nonlinear optical processes in gas-exposed bow-tie nanoantennas. We find multiphoton- and strong-field-induced atomic excitation and ionization resulting in extreme-ultraviolet fluorescence, as well as third- and fifth-harmonic generation intrinsic to the nanostructures. Identifying the intensity-dependent spectral fingerprint of atomic fluorescence, we gauge local plasmonic fields. Whereas intensities sufficient for high-harmonic generation are indeed achieved in the near-field, the nanoscopic volume is found to prohibit an efficient conversion. Our results illustrate opportunities and challenges in highly nonlinear plasmonics and its extension to the extreme ultraviolet.