Phase-Resolved Mapping of the Near-Field Vector and Polarization State in Nanoscale Antenna Gaps
Phase-Resolved Mapping of the Near-Field Vector and Polarization State in Nanoscale Antenna Gaps
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DOI：
10.1021/nl101693a
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发表时间：
2010-09-01
期刊：
影响因子：
10.8
通讯作者：
Hillenbrand, R.
中科院分区：
文献类型：
--
作者：
Schnell, M.;Garcia-Etxarri, A.;Hillenbrand, R.
我们证明了局部近场矢量和极化状态，在平面天线结构和纳米天线间隙可以确定散射型近场光学显微镜（S-SNOM）。近场矢量的重建从振幅和相位图像的平面内和我们的近场分量得到的偏振分辨干涉检测。中红外反蝴蝶结天线的实验产生一个矢量近场分布与前所未有的分辨率约为10 nm，并在良好的协议与数值模拟。此外，我们提供了第一个直接的实验证据表明，在天线间隙的纳米级限制和强烈增强的领域是线性极化。s-SNOM矢量场映射为在可见光和太赫兹频率之间的宽光谱范围内对纳米光子结构进行全面的近场表征铺平了道路，这对于超材料，光学传感器和波导的未来开发和质量控制至关重要。
We demonstrate that the local near-field vector and polarization state, On planar antenna structures and in nanoscale antenna gaps can be determined by scattering-type near-field optical microscopy (s-SNOM). The near-field vector is reconstructed from the amplitude and phase images of the in- and our-of-plane near-field components obtained by polarization-resolved interferometric detection. Experiments with a mid-infrared inverse bowtie antenna yield a vectorial near-field distribution with unprecedented resolution of about 10 nm and in excellent agreement with numerical simulations. Furthermore, we provide first direct experimental evidence that the nanoscale confined and strongly enhanced fields at the antenna gap are linearly polarized. s-SNOM vector-field mapping paves the way to a full near-field characterization of nanophotonic structures in the broad spectral range between visible and terahertz frequencies, which is essential for future development and quality control of metamaterials, optical sensors, and waveguides.