Polaritonics Platform for Terahertz Signal Processing, MultipleScattering, and Field Enhancement

该项目的目的是研究：(i)在传感和成像应用中的多重散射太赫兹信号，以及（ii）在光谱学中的太赫兹场增强。在主题(i)中，多重电磁波散射模型将使用太赫兹极化电子学平台进行测试。飞秒激光加工将用于在铌酸锂晶体薄膜上钻孔和雕刻具有不同尺寸和空间分布特性的指定结构。太赫兹波将在薄膜中产生并被探测到。该结果将指导太赫兹成像方法的发展。在主题（ii）中，将开发掺杂半导体腔和波导来提供太赫兹场增强。这些场可能足以驱动高度非线性的材料响应，包括结构相变和介电击穿。这将允许直接的时间分辨光学观测以及对复杂材料转换的广泛控制。与微波和光学相比，太赫兹频谱一直没有得到充分利用，这在很大程度上是因为缺乏信号源和探测器。这些领域的最新进展为控制太赫兹信号、成像和光谱学的新方法提供了机会，这些主题将得到讨论。更广泛的影响两名博士生将获得该奖项的支持。在麻省理工学院，该项目将与纳尔逊集团开展的大学预科外展项目的计划扩展相吻合。在普渡大学，本科生将被招募到韦伯小组参与这个项目。

Objective The objectives if this project are to investigate: (i) Multiply-scattered terahertz signals in sensing and imaging applications, and (ii) Terahertz field enhancement for spectroscopy. In Topic (i), models of multiple electromagnetic wave scattering will be tested using a terahertz polaritonics platform. Femtosecond laser machining will be used to drill holes and carve specified structures with different dimensions and spatial distribution properties into lithium niobate crystalline films. Terahertz waves will be generated and detected in the films. The results will guide the development of methods for terahertz imaging. In Topic (ii), doped semiconductor cavities and waveguides will be developed to provide terahertz field enhancement. The fields may be sufficient to drive highly nonlinear material responses including structural phase transitions and dielectric breakdown. This will permit direct time-resolved optical observation as well as extensive control over complex material transformations.Intellectual MeritThe terahertz spectrum has been underutilized, relative to microwaves and optics, in large part because of a dearth of sources and detectors. Recent progress in these areas presents opportunities for new methods for controlling terahertz signals, for imaging, and for spectroscopy, and these topics will be addressed. Broader ImpactTwo Ph.D. students will be supported by this award. At MIT, the project will dovetail with a planned expansion of a pre-college outreach program run by the Nelson group. At Purdue, undergraduate students will be recruited to work on this project in the Webb group.