Double-slit time diffraction at optical frequencies
Double-slit time diffraction at optical frequencies
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DOI：
10.1038/s41567-023-01993-w
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发表时间：
2023-04-03
期刊：
影响因子：
19.6
通讯作者：
Sapienza，Riccardo
中科院分区：
文献类型：
--
作者：
Tirole，Romain;Vezzoli，Stefano;Sapienza，Riccardo
双缝实验波通过空间中的一个薄的双孔传播已经证实了量子物体的波粒二象性，如单光子、电子、中子、原子和大分子。然而，杨氏双缝实验的时间对应物--波与界面的双重时间调制相互作用--仍然难以捉摸。在这里，我们报告这样一个经典的杨氏双缝实验的时域版本：一束光在时间上被选通两次，在频谱上产生干涉。“时间裂缝”，窄到足以产生光频衍射，是由氧化铟锡薄膜在其ε近零点附近的光激发产生的。时间缝之间的间隔决定了频谱中振荡的周期，而条纹可见度在频率上的衰减揭示了时间缝的形状。令人惊讶的是，比现有理论预期的更多的振荡是可见的，这意味着上升时间接近光学周期。这一结果使进一步探索时变物理，对频谱合成的波和应用，如信号处理和神经形态计算。
Double-slit experiments—where a wave is transmitted through a thin double aperture in space—have confirmed the wave–particle duality of quantum objects, such as single photons, electrons, neutrons, atoms and large molecules. Yet, the temporal counterpart of Young’s double-slit experiment—a wave interacting with a double temporal modulation of an interface—remains elusive. Here we report such a time-domain version of the classic Young’s double-slit experiment: a beam of light twice gated in time produces an interference in the frequency spectrum. The ‘time slits’, narrow enough to produce diffraction at optical frequencies, are generated from the optical excitation of a thin film of indium tin oxide near its epsilon-near-zero point. The separation between time slits determines the period of oscillations in the frequency spectrum, whereas the decay of fringe visibility in frequency reveals the shape of the time slits. Surprisingly, many more oscillations are visible than expected from existing theory, implying a rise time that approaches an optical cycle. This result enables the further exploration of time-varying physics, towards the spectral synthesis of waves and applications such as signal processing and neuromorphic computation.