Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
Max Planck Centre for Extreme and Quantum Photonics, Ottawa, ON, K1N 6N5, Canada.
Nat Commun. 2023 May 5;14(1):2595. doi: 10.1038/s41467-023-38354-3.
Slow motion movies allow us to see intricate details of the mechanical dynamics of complex phenomena. If the images in each frame are replaced by terahertz (THz) waves, such movies can monitor low-energy resonances and reveal fast structural or chemical transitions. Here, we combine THz spectroscopy as a non-invasive optical probe with a real-time monitoring technique to demonstrate the ability to resolve non-reproducible phenomena at 50k frames per second, extracting each of the generated THz waveforms every 20 μs. The concept, based on a photonic time-stretch technique to achieve unprecedented data acquisition speeds, is demonstrated by monitoring sub-millisecond dynamics of hot carriers injected in silicon by successive resonant pulses as a saturation density is established. Our experimental configuration will play a crucial role in revealing fast irreversible physical and chemical processes at THz frequencies with microsecond resolution to enable new applications in fundamental research as well as in industry.
慢动作电影使我们能够看到复杂现象的机械动力学的复杂细节。如果每一帧的图像都被太赫兹（THz）波所取代，这样的电影可以监测低能量共振，并揭示快速的结构或化学转变。在这里，我们将太赫兹光谱学作为一种非侵入性的光学探针与实时监测技术相结合，以证明以每秒 50k 帧的速度解析不可重复现象的能力，每 20μs 提取生成的每一个太赫兹波形。该概念基于一种光电子时间拉伸技术，以实现前所未有的数据采集速度，通过监测连续共振脉冲注入硅中的热载流子的亚毫秒动力学来实现，当达到饱和密度时，该技术作为一个饱和密度被建立。我们的实验配置将在以微秒分辨率在太赫兹频率下揭示快速不可逆物理和化学过程方面发挥关键作用，从而为基础研究以及工业中的新应用开辟道路。
