Phase of the electric field localized at surface-immobilized gold nanospheres determined by second-harmonic interferometry
Phase of the electric field localized at surface-immobilized gold nanospheres determined by second-harmonic interferometry
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DOI：
10.1103/physrevb.83.085425
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发表时间：
2011-02-28
影响因子：
3.7
通讯作者：
Kajikawa, Kotaro
中科院分区：
文献类型：
--
作者：
Yamaguchi, Tatsuya;Okawa, Haruki;Kajikawa, Kotaro
固定在金表面上的金纳米球之间有纳米间隙，构成了一个很有前途的等离子体系统。虽然许多工作已经研究了位于等离子体纳米结构中的增强电场的大小，但对它们的相结构知之甚少。为了探测等离子体纳米结构附近电场的相位，我们对表面固定的金纳米球(SIGN)上的半花青单分子膜和纳米间隙中的半花青单分子膜的二次谐波(SH)光进行了干涉测量。从标志上的半花青单分子层开始的SH相几乎与纳米间隙中的半花青单分子层的SH相相反。这一结果得到了基于高阶多极子的局域电场的理论计算的支持。
Gold nanospheres immobilized above a gold surface, with a nanometer gap between, comprise a promising plasmonic system. Although many works have studied the magnitude of the enhanced electric fields that are localized at the plasmonic nanostructure, little is known about their phase. To probe the phase of the electric field localized adjacent to the plasmonic nanostructure, we undertook interferometry for second-harmonic (SH) light from hemicyanine monolayers on the surface-immobilized gold nanospheres (SIGNs), and from a hemicyanine monolayer in the nanogap. The SH phase from the hemicyanine monolayer on the SIGNs was found to be almost opposite to that from the hemicyanine monolayer in the nanogap. This result is supported by a theoretical calculation of the localized electric fields based on higher order multipoles.