Local optical responses of plasmon resonances visualised by near-field optical imaging
Local optical responses of plasmon resonances visualised by near-field optical imaging
复制标题
DOI：
10.1039/c4cp05951d
复制
发表时间：
2015-01-01
影响因子：
3.3
通讯作者：
Imura, Kohei
中科院分区：
文献类型：
--
作者：
Okamoto, Hiromi;Narushima, Tetsuya;Imura, Kohei
贵金属纳米结构独特的光学特性主要来源于表面等离子体共振。为了利用和设计等离子体激元的独特特性，研究纳米结构附近的光场结构是至关重要的。由于光场结构的空间尺度基本上小于与等离子体共振的辐射波长，因此需要实现超过光的衍射极限的空间分辨率的光学成像方法来可视化场。在这篇文章中，我们回顾了近场光学显微镜等离子体共振直接实验可视化的研究。我们简要描述了近场光学显微镜用于研究贵金属纳米粒子的方法，并与几个典型的单金纳米粒子的等离子体共振的空间特征，特别是驻波函数的等离子体，可以直接可视化近场成像。然后，我们描述了我们最近的努力，可视化超快动力学的金属纳米结构等离子体激元激发后，这是基于近场超快成像测量。最近引起注意的金属纳米结构的另一个值得注意的方面是等离子体的手性。在这里，我们描述了近场光学成像和分析的方法和例子的手性等离子体激发金属纳米结构。
The unique optical characteristics of noble metal nanostructures have their origin principally in surface plasmon resonances. To exploit and design the unique characteristics arising from plasmons, an investigation of optical field structures adjacent to the nanostructure is of fundamental importance. As the spatial scale of the optical field structures is essentially smaller than the radiation wavelength in resonance with the plasmon, optical imaging methods that achieve spatial resolution beyond the diffraction limit of light are necessary to visualise the fields. In this article, we review the studies of direct experimental visualisation of plasmon resonances using near-field optical microscopy. We briefly describe the method of near-field optical microscopy used to study noble metal nanoparticles and show with several typical single gold nanoparticles that the spatial features of plasmon resonances, in particular the standing wave functions of the plasmons, can be directly visualised by near-field imaging. We then describe our recent efforts to visualise ultrafast dynamics in metal nanostructures following plasmonic excitation, which are based on near-field ultrafast imaging measurements. Another notable aspect of metal nanostructures that has attracted attention recently is the chirality of plasmons. Here, we describe a method and examples of near-field optical imaging and analyses of chiral plasmons excited on metal nanostructures.