Ultrafast terahertz monitoring of extremely high nonlinearities in semiconductors and dynamical excitons in strongly correlated materials

超快太赫兹监测半导体中的极高非线性和强相关材料中的动态激子

• 批准号: RTI-2018-00990
• 负责人: Ménard, JeanMichel
• 金额: $ 10.91万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=642254
• 关键词: Ultrafast; terahertz; monitoring; extremely; nonlinearities

Located between the near-infrared (NIR) and the microwave regions, terahertz (THz) radiation shares properties with these two spectral domains making it a unique tool for spectroscopic applications. On one hand, its moderately high photon energy covers an ideal range to interact with various elementary excitations such as phonons, excitons, and molecular vibrations, which is why THz radiation is increasingly used in academia and industry to characterize semiconductors, image bio-tissues and identify chemical agents. On the other hand, its wavelength is still long enough to enable ultrafast NIR pulses to trace its relatively slow oscillating electric field via a technique called electro-optic sampling. By comparing the time-resolved THz pulse incident on and transmitted through a sample, one can retrieve the full complex dielectric response of that material. This information can also be extracted as a function of time delay relative to a synchronized excitation pump pulse to perform ultrafast THz spectroscopy and monitor dynamical condensed-matter systems.

Terahertz（THz）辐射位于近红外（NIR）和微波区域之间，与这两个光谱域共享特性，使其成为光谱应用的独特工具。一方面，其中等高的光子能量涵盖了与各种基本激发相互作用的理想范围，例如声子，激子和分子振动，这就是为什么在学术界和工业中越来越多地使用THZ辐射来表征半导体，图像生物生物 - 生物组织和识别化学剂的原因。另一方面，其波长仍然足够长，可以使超快NIR脉冲通过称为电光抽样的技术追踪其相对较慢的振动电场。通过比较在样品上的时间分辨的THZ脉冲和通过样品传输，可以检索该材料的完整复杂介电响应。相对于同步激发泵脉冲的时间延迟，也可以提取此信息，以执行超快THZ光谱并监视动力学凝结系统。