Institut national de la recherche scientifique, Centre Énergie Matériaux Télécommunications, Varennes, QC, J3X 1P7, Canada.
Nat Commun. 2023 Mar 27;14(1):1704. doi: 10.1038/s41467-023-37285-3.
Multidimensional imaging of transient events has proven pivotal in unveiling many fundamental mechanisms in physics, chemistry, and biology. In particular, real-time imaging modalities with ultrahigh temporal resolutions are required for capturing ultrashort events on picosecond timescales. Despite recent approaches witnessing a dramatic boost in high-speed photography, current single-shot ultrafast imaging schemes operate only at conventional optical wavelengths, being suitable solely within an optically-transparent framework. Here, leveraging on the unique penetration capability of terahertz radiation, we demonstrate a single-shot ultrafast terahertz photography system that can capture multiple frames of a complex ultrafast scene in non-transparent media with sub-picosecond temporal resolution. By multiplexing an optical probe beam in both the time and spatial-frequency domains, we encode the terahertz-captured three-dimensional dynamics into distinct spatial-frequency regions of a superimposed optical image, which is then computationally decoded and reconstructed. Our approach opens up the investigation of non-repeatable or destructive events that occur in optically-opaque scenarios.
瞬态事件的多维成像已被证明是揭示物理、化学和生物学中许多基本机制的关键。特别是，需要具有超高时间分辨率的实时成像模式来捕获皮秒时间尺度上的超短事件。尽管最近的方法在高速摄影方面取得了显著的进步，但目前的单次超快成像方案仅在传统光学波长下运行，仅适用于光学透明的框架内。在这里，我们利用太赫兹辐射的独特穿透能力，展示了一种单次超快太赫兹摄影系统，该系统可以在非透明介质中以亚皮秒的时间分辨率捕获复杂超快场景的多个帧。通过在时间和空间频率域中复用光学探测光束，我们将太赫兹捕获的三维动力学编码到叠加光学图像的不同空间频率区域中，然后通过计算进行解码和重建。我们的方法为研究在光学不透明场景中发生的不可重复或破坏性事件开辟了道路。
