Keren-Zur Shay, Tal Mai, Fleischer Sharly, Mittleman Daniel M, Ellenbogen Tal
Department of Physical Electronics, School of Electrical Engineering, Tel-Aviv University, 6997801, Tel Aviv, Israel.
Center for Light-Matter Interaction, Tel-Aviv University, 6779801, Tel-Aviv, Israel.
Nat Commun. 2019 Apr 16;10(1):1778. doi: 10.1038/s41467-019-09811-9.
The past two decades have witnessed an ever-growing number of emerging applications that utilize terahertz (THz) waves, ranging from advanced biomedical imaging, through novel security applications, fast wireless communications, and new abilities to study and control matter in all of its phases. The development and deployment of these emerging technologies is however held back, due to a substantial lack of simple methods for efficient generation, detection and manipulation of THz waves. Recently it was shown that uniform nonlinear metasurfaces can efficiently generate broadband single-cycle THz pulses. Here we show that judicious engineering of the single-emitters that comprise the metasurface, enables to obtain unprecedented control of the spatiotemporal properties of the emitted THz wavepackets. We specifically demonstrate generation of propagating spatiotemporal quadrupole and few-cycles THz pulses with engineered angular dispersion. Our results place nonlinear metasurfaces as a new promising tool for generating application-tailored THz fields with controlled spatial and temporal characteristics.
在过去二十年中，利用太赫兹（THz）波的新兴应用不断涌现，数量日益增多，涵盖了先进的生物医学成像、新型安全应用、高速无线通信以及研究和控制物质所有相态的新能力等领域。然而，由于严重缺乏用于高效产生、检测和操纵太赫兹波的简单方法，这些新兴技术的开发和部署受到了阻碍。最近有研究表明，均匀非线性超表面能够高效产生宽带单周期太赫兹脉冲。在此我们表明，对构成超表面的单个发射器进行明智的设计，能够实现对所发射太赫兹波包的时空特性前所未有的控制。我们特别展示了利用工程化角色散产生传播的时空四极子和少周期太赫兹脉冲。我们的结果表明，非线性超表面是一种有前景的新工具，可用于产生具有可控空间和时间特性的、适用于特定应用的太赫兹场。
