Wave absorption in time-invariant, passive thin films is fundamentally limited by a trade-off between bandwidth and overall thickness. In this work, we investigate the use of temporal switching to reduce signal reflections from a thin grounded slab over broader bandwidths. We extend quasi-normal mode theory to time switching, developing an ab initio formalism that can model a broad class of time-switched structures. Our formalism provides optimal switching strategies to maximize the bandwidth over which minimal reflection is achieved, showing promising prospects for time-switched nanophotonic and metamaterial systems to overcome the limits of time-invariant, passive structures.

中文翻译：

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临时切换以扩展薄吸收体的带宽

时不变的无源薄膜中的波吸收从根本上受到带宽和总厚度之间的折衷的限制。在这项工作中，我们研究了使用时间切换来减少较薄的接地板在更宽的带宽上的信号反射。我们将准法则模式理论扩展到时间切换，开发了一种从头算形式主义，可以对大范围的时间切换结构进行建模。我们的形式主义提供了最佳的切换策略，以最大化实现最小反射的带宽，这显示了时光转换纳米光子和超材料系统有望克服时不变，无源结构的局限性的广阔前景。