In this paper, we describe a new method to improve fast-light transmission, which uses cascades. We design a simple plasmonic device that enables plasmonic-induced absorption (PIA). It consists mainly of two parallel rectangular cavities. The numerical results simulated by using the finite element method (FEM) confirm its function. The corresponding group delay-time can reach –0.146 ps for the PIA window. Based on this result, we propose a cascade device, with the dual-rectangular cavity system as building block, to improve fast-light transmission even more. The results indicate that the cascade scheme can increase the group delay-time to –0.456 ps, which means the fast-light feature is substantially enhanced compared with the non-cascading approach. The effect of the distance between two cascade resonators and other structural parameters is also investigated. Finally, we use this design concept to build a refractive-index sensor with a sensitivity of 701 nm/RIU.

中文翻译：

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级联方案增强等离子体诱导的吸收及其在折射率传感器中的应用

在本文中，我们描述了一种使用级联技术改善快速光透射的新方法。我们设计了一个简单的等离子设备，可实现等离子诱导吸收（PIA）。它主要由两个平行的矩形腔组成。使用有限元方法（FEM）进行的数值模拟证实了其功能。对于PIA窗口，相应的组延迟时间可以达到–0.146 ps。基于此结果，我们提出了一种以双矩形腔系统为构建模块的级联设备，以进一步提高快速透光率。结果表明，级联方案可以将群延迟时间增加到–0.456 ps，这意味着与非级联方法相比，快速发光功能得到了显着增强。还研究了两个级联谐振器之间的距离和其他结构参数的影响。最后，我们使用该设计概念来构建灵敏度为701 nm / RIU的折射率传感器。