Max-Planck-Institut für Festkorperförschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany.
Nano Lett. 2010 Sep 8;10(9):3596-603. doi: 10.1021/nl101921y.
Recent advances in nanolithography have allowed shifting of the resonance frequency of antennas into the optical and visible wavelength range with potential applications, for example, in single molecule spectroscopy by fluorescence and directionality enhancement of molecules. Despite such great promise, the analytical means to describe the properties of optical antennas is still lacking. As the phase velocity of currents at optical frequencies in metals is much below the speed of light, standard radio frequency (RF) antenna theory does not apply directly. For the fundamental linear wire antenna, we present an analytical description that overcomes this shortage and reveals profound differences between RF and plasmonic antennas. It is fully supported by apertureless scanning near-field optical microscope measurements and finite-difference time-domain simulations. This theory is a starting point for the development of analytical models of more complex antenna structures.
最近的纳米光刻技术进展使得天线的共振频率能够转移到光学和可见光波长范围内，具有潜在的应用，例如通过荧光和分子的方向性增强进行单分子光谱学。尽管有如此巨大的前景，但描述光学天线特性的分析手段仍然缺乏。由于金属中光频电流的相速度远低于光速，因此标准的射频 (RF) 天线理论不能直接应用。对于基本的线性导线天线，我们提出了一种分析描述，克服了这一不足，并揭示了 RF 和等离子体天线之间的深刻差异。它得到了无掩模扫描近场光学显微镜测量和有限差分时域模拟的完全支持。该理论是开发更复杂天线结构的分析模型的起点。
