闭合锥形间隙的共振等离子体纳米聚焦。

Resonant plasmon nanofocusing by closed tapered gaps.

机构信息

Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, Aalborg Øst, Denmark.

出版信息

Nano Lett. 2010 Jan;10(1):291-5. doi: 10.1021/nl903563e.

PMID:20028028

Abstract

We study radiation nanofocusing by closed tapered gaps, i.e. metal V-grooves, under normal illumination, and discover that the local field inside a groove can be resonantly enhanced due to interference of counter-propagating gap plasmons. Considering V-grooves milled in gold, we analyze this phenomenon theoretically, deriving an analytic expression for the resonance condition and predicting more than 550-fold intensity enhancements at resonance, and observe it experimentally with two-photon photoluminescence microscopy, demonstrating more than 100-fold intensity enhancements.

摘要

我们研究了在正常照明下通过封闭的锥形间隙（即金属 V 型槽）实现的辐射纳米聚焦，并发现由于反向传播的间隙等离子体激元的干涉，槽内的局部场可以产生共振增强。考虑到在金中铣制的 V 型槽，我们从理论上对此现象进行了分析，得出了共振条件的解析表达式，并预测在共振时强度可增强 550 多倍，我们用双光子光致发光显微镜进行了实验观察，证实了强度可增强 100 多倍。