基于TPPs-SPPs混合模式的激发以增强单纳米缝异常透射

发布时间：2018-01-21 18:53

  本文关键词： 异常透射 塔姆激元 表面等离子体激元 类法布里-珀罗腔共振　出处：《物理学报》2016年20期 　论文类型：期刊论文

【摘要】：单纳米金属缝结构,由于其结构紧凑、易于集成、耦合效率高,常常在基于表面等离子体激元(surface plasmon polaritons,SPPs)的纳米结构器件中用于构建光源.但是,单纳米缝的低透射率一直是该结构向实际应用转化中的问题;实际上,如何有效地增强其透射率一直是研究的重点.本文提出了一种有效增强单纳米缝异常透射的方法和结构,该结构由分布式布拉格反射镜(distributed bragg reflector,DBR)和金属银薄膜纳米缝构成.当TM偏振光由DBR侧入射至DBR-银纳米缝结构时,DBR-银膜界面上的塔姆激元(Tamm plasmon polaritons,TPPs)和纳米缝中的SPPs能够同时被有效激发,并相互耦合形成TPPs-SPPs混合模式,当TPPs与SPPs满足波矢匹配条件时,利用TPPs的局域场增强效应可显著提高SPPs的激发效率,结合纳米缝中的类法布里-珀罗腔共振效应,最终可实现对单纳米缝异常透射率的有效增强.本文利用传输矩阵法和有限元算法分析了DBR-银纳米缝结构上单纳米缝的透射特性.经过参数优化,在银膜厚度为100 nm、纳米缝宽为11 nm时,DBR-银纳米缝结构的最大透射率为0.166,相对于TiO_2银纳米缝结构(无DBR)的透射率(0.01),提高了16倍.该研究从基本物理机理出发,实现了对单纳米缝异常透射的增强,研究结果在纳米光子学、近场光学成像与探测、极化激元激光器等相关领域具有潜在的应用价值.
[Abstract]:Because of its compact structure, easy integration and high coupling efficiency, single nanometallic slit structure is often used in surface plasmon polaritons based on surface plasmon excitation. However, the low transmittance of single nanocrystalline slit is always a problem in the conversion of the structure to practical application. In fact, how to effectively enhance its transmittance has been the focus of research. In this paper, an effective method and structure for enhancing the abnormal transmission of single nano-slit is proposed. The bragg reflector is distributed by distributed Bragg reflector. When TM polarized light is incident from the DBR side to the DBR- silver nanostructure. Both the Tamm plasmon polaritons at the interface of DBR- silver film and the SPPs in the nanocrystalline can be effectively excited at the same time. When TPPs and SPPs satisfy the condition of wave vector matching, the local field enhancement effect of TPPs can significantly improve the excitation efficiency of SPPs. Combined with the Fabry-Perot cavity resonance effect in the nanocracks. In this paper, the transmission characteristics of DBR- silver nanostructure are analyzed by transmission matrix method and finite element method, and the parameters are optimized. The maximum transmittance of DBR- silver nanostructure is 0.166 when the silver film thickness is 100 nm and the gap width is 11 nm. The transmittance of TiO_2 silver nanostructure (no DBR) was increased by 16 times compared with that of silver nanostructure (no DBR). This study realized the enhancement of abnormal transmission of single nano-slit based on the basic physical mechanism. The results have potential applications in the fields of nano-photonics, near-field optical imaging and detection, polarimetric lasers and so on.
【作者单位】： 南京邮电大学光电工程学院;
【基金】：国家自然科学基金(批准号:61575096);国家自然科学基金青年科学基金(批准号:11404170) 国家教育部留学回国人员科研启动基金(批准号:105757) 江苏省基础研究计划基金(批准号:BK20131383)资助的课题~~
【分类号】：TB383.1
【正文快照】： 1引言 光学异常透射(extraordinary optical transmission,EOT)现象突破了传统孔径理论的限制,而基于EOT现象的纳米光子器件在纳米光子集成、纳米光刻、近场成像与探测、生物传感器等领域的相关应用引起人们越来越多的关注,成为近年来纳米光子学的一个研究热点[1-7].1998年Eb，

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