Directional excitation of surface plasmon polaritons via nanoslits under varied incidence observed using leakage radiation microscopy.
Directional excitation of surface plasmon polaritons via nanoslits under varied incidence observed using leakage radiation microscopy.
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DOI：
10.1364/oe.20.004893
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发表时间：
2012-02
期刊：
影响因子：
3.8
通讯作者：
Y. Sonnefraud;Sarp Kerman;G. Di Martino;D. Lei;S. Maier
中科院分区：
文献类型：
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作者：
Y. Sonnefraud;Sarp Kerman;G. Di Martino;D. Lei;S. Maier
表面等离子体激元（SPP）激发在薄的金膜和空气之间的界面处通过蚀刻到膜中的纳米狭缝的照明。利用泄漏辐射显微镜测量了泵浦光入射角从0°到20°变化时，远离狭缝的两个传输方向的耦合效率。我们发现，在单缝和缝对的情况下，非垂直入射可以实现SPP向一个方向的优先耦合。在一个方向上激发的SPP的比例可以超过90%。我们进一步提供了一个简单的模型的过程中，并直接比较两种方法的性能。
Surface Plasmon Polaritons (SPPs) are excited at the interface between a thin gold film and air via the illumination of nanoslits etched into the film. The coupling efficiency to the two propagation directions away from the slits is determined by leakage radiation microscopy, when the angle of incidence of the pump beam is changed from 0° to 20°. We find that preferential coupling of SPPs into one direction can be achieved for non-normal incidence in the case of single slits and slit pairs. The proportion of SPP excited into one direction can be in excess of 90%. We further provide a simple model of the process, and directly compare the performances of the two approaches.