Chen Jingdong, Xiang Jin, Jiang Shuai, Dai Qiaofeng, Tie Shaolong, Lan Sheng
Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China.
College of Physics and Information Engineering, Minnan Normal University, Zhangzhou 363000, China.
Nanomaterials (Basel). 2019 Jan 31;9(2):175. doi: 10.3390/nano9020175.
We proposed the use of the evanescent wave generated in a total internal reflection configuration to excite large gold nanospheres and investigated the radiations of the high-order plasmon modes supported in gold nanospheres. It was revealed that the evanescent wave excitation is equivalent to the excitation by using both the incident and reflected light, offering us the opportunity to control the orientation of the electric field used to excite nanoparticles. In addition, it was found that the scattering light intensity is greatly enhanced and the background noise is considerably suppressed, making it possible to detect the radiations from high-order plasmon modes. Moreover, the influence of the mirror images on the scattering induced by a metal substrate is eliminated as compared with the surface plasmon polariton excitation. By exciting a gold nanosphere with -polarized light and detecting the scattering light with a -polarized analyzer, we were able to reveal the radiation from the electric quadrupole mode of the gold nanosphere in both the spatial and the frequency domains. Our findings are important for characterizing the radiations from the high-order modes of large nanoparticles and useful for designing nanoscale photonic devices.
我们提出利用全内反射配置中产生的倏逝波来激发大尺寸金纳米球，并研究了金纳米球中支持的高阶等离子体模式的辐射。结果表明，倏逝波激发等同于使用入射光和反射光进行激发，这为我们提供了控制用于激发纳米粒子的电场方向的机会。此外，发现散射光强度大大增强，背景噪声得到显著抑制，从而有可能检测高阶等离子体模式的辐射。而且，与表面等离子体激元激发相比，消除了镜像对金属基板诱导散射的影响。通过用偏振光激发金纳米球并用偏振分析仪检测散射光，我们能够在空间和频域中揭示金纳米球电四极模式的辐射。我们的发现对于表征大尺寸纳米粒子高阶模式的辐射很重要，并且对于设计纳米级光子器件很有用。
