Near-field optical imaging of plasmon modes in gold nanorods
Near-field optical imaging of plasmon modes in gold nanorods
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DOI：
10.1063/1.1873692
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发表时间：
2005-04-15
影响因子：
4.4
通讯作者：
Okamoto, H
中科院分区：
文献类型：
--
作者：
Imura, K;Nagahara, T;Okamoto, H
利用孔径型扫描近场光学显微镜研究了单金纳米棒的光学性质。单金纳米棒的近场透射谱显示出多个纵向表面等离子体共振。在这些共振波长处观察到的透射图像显示沿纳米棒长轴的振荡模式。振荡次数随观测波长的减小而增加。这些空间特征可以通过计算的局部态密度图很好地再现，并归因于纳米棒内部等离子体模式的空间特征。通过绘制等离子体模式的共振频率与透射图像的波矢量的关系，得到了金纳米棒中等离子体的色散关系。(c) 2005年美国物理研究所。
We have investigated optical properties of single gold nanorods by using an apertured-type scanning near-field optical microscope. Near-field transmission spectrum of single gold nanorod shows several longitudinal surface plasmon resonances. Transmission images observed at these resonance wavelengths show oscillating pattern along the long axis of the nanorod. The number of oscillation increases with decrement of observing wavelength. These spatial characteristics were well reproduced by calculated local density-of-states maps and were attributed to spatial characteristics of plasmon modes inside the nanorods. Dispersion relation for plasmons in gold nanorods was obtained by plotting the resonance frequencies of the plasmon modes versus the wave vectors obtained from the transmission images. (c) 2005 American Institute of Physics.