Marqués R, Mesa F, Jelinek L, Medina F
Departamento de Electrónica y Electromagnetismo, Universidad de Sevilla, Sevilla, Spain.
Opt Express. 2009 Mar 30;17(7):5571-9. doi: 10.1364/oe.17.005571.
In this letter, the problem of extraordinary (ET) transmission of electromagnetic waves through opaque screens perforated with subwave-length holes is addressed from an analytical point of view. Our purpose was to find a closed-form expression for the transmission coefficient in a simple case in order to explore and clarify, as much as possible, the physical background of the phenomenon. The solution of this canonical example, apart from matching quite well with numerical simulations given by commercial solvers, has provided new insight in extraordinary transmission as well as Wood's anomaly. Thus, our analysis has revealed that one of the key factors behind ET is the continuous increase of excess electric energy around the holes as the frequency approaches the onset of some of the higher-order modes associated with the periodicity of the screen. The same analysis also helps to clarify the role of surface modes -or spoof plasmons- in the onset of ET.
在这封信中，从分析的角度探讨了电磁波通过带有亚波长孔的不透明屏幕的异常（ET）传输问题。我们的目的是在一个简单的情况下找到传输系数的封闭形式表达式，以便尽可能地探索和阐明该现象的物理背景。这个典型例子的解决方案，除了与商业求解器给出的数值模拟相当吻合外，还为异常传输以及伍德异常提供了新的见解。因此，我们的分析表明，ET背后的关键因素之一是随着频率接近与屏幕周期性相关的一些高阶模式的起始频率，孔周围多余电能的持续增加。同样的分析也有助于阐明表面模式——或虚拟等离激元——在ET起始中的作用。
