Coherent wave control is of key importance across a broad range of fields such as electromagnetics, photonics, and acoustics. It enables us to amplify or suppress the outgoing waves via engineering amplitudes and phases of multiple incidences. However, within a purely spatially (temporally) engineered medium, coherent wave control requires the frequency of the associated incidences to be identical (opposite). In this work, this conventional constraint is broken by generalizing coherent wave control into a spatiotemporally engineered medium is broken, i.e., the system featuring a dynamic interface. Owing to the broken translational symmetry in space and time, both the subluminal and superluminal interfaces allow interference between scattered waves regardless of their different frequencies and wavevectors. Hence, one can flexibly eliminate the backward‐ or forward‐propagating waves scattered from the dynamic interfaces by controlling the incident amplitudes and phases. The work not only presents a generalized way for reshaping arbitrary waveforms but also provides a promising paradigm to generate ultrafast pulses using low‐frequency signals. It has also implemented suppression of forward‐propagating waves in microstrip transmission lines with fast photodiode switches.

中文翻译：

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动态界面上的广义相干波控制


相干波控制在电磁学、光子学和声学等广泛领域中都至关重要。它使我们能够通过工程振幅和多个入射相位来放大或抑制出射波。然而，在纯粹的空间（时间）工程介质中，相干波控制要求相关入射的频率相同（相反）。在这项工作中，通过将相干波控制推广到时空工程介质中来打破这种常规约束，即具有动态界面的系统被打破。由于空间和时间上的平移对称性被打破，亚光速和超光速界面都允许散射波之间的干涉，而不管它们的频率和波矢量如何。因此，可以通过控制入射幅度和相位来灵活地消除从动态界面散射的向后或向前传播的波。这项工作不仅提出了一种重塑任意波形的通用方法，而且还提供了一种使用低频信号生成超快脉冲的有前途的范例。它还使用快速光电二极管开关抑制了微带传输线中的正向传播波。