Crouse David, Keshavareddy Pavan
Opt Express. 2005 Oct 3;13(20):7760-71. doi: 10.1364/opex.13.007760.
An analysis of several types of one-dimensional transmission gratings structures with different metal contact geometries is used to study the role of horizontally oriented surface plasmons, cavity modes and other optical modes in enhanced transmission. Several competing theories of enhanced transmission are presented and the analysis of the structures in this work clearly establishes that horizontal surface plasmons can enhance or inhibit transmission depending on whether the HSPs establish vortices of energy that circulate in a direction that enhances or inhibits the flow of energy through the center of the grooves. Also, we show that enhanced transmission can be achieved using a different mechanism than previously reported in the literature. This new mechanism is a Fabry-Perot resonance produced by small notches in the top metal surface, which concentrates the energy from the incident beam and steers it through the slit openings and into the substrate. Finally, applications of the different structures and their optical modes are discussed including chemical and biological sensors and high bandwidth, high responsivity InGaAs metal-semiconductor-metal photodetectors.
通过对具有不同金属接触几何形状的几种一维透射光栅结构进行分析，来研究水平取向表面等离子体激元、腔模和其他光学模式在增强透射中的作用。文中介绍了几种关于增强透射的相互竞争的理论，并且对这项工作中的结构分析清楚地表明，水平表面等离子体激元是增强还是抑制透射，取决于它们是否形成能量涡旋，这些涡旋沿增强或抑制通过凹槽中心的能量流动的方向循环。此外，我们表明可以使用一种不同于文献中先前报道的机制来实现增强透射。这种新机制是由顶部金属表面的小凹槽产生的法布里-珀罗共振，它将入射光束的能量集中起来，并引导其通过狭缝开口进入衬底。最后，讨论了不同结构及其光学模式的应用，包括化学和生物传感器以及高带宽、高响应度的铟镓砷金属-半导体-金属光电探测器。
