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.

太赫兹 (THz) 辐射位于近红外 (NIR) 和微波区域之间，与这两个光谱域具有相同的特性，使其成为光谱应用的独特工具。一方面，其较高的光子能量覆盖了与声子、激子和分子振动等各种基本激发相互作用的理想范围，这就是为什么太赫兹辐射越来越多地应用于学术界和工业界来表征半导体、成像生物组织和识别化学试剂。另一方面，它的波长仍然足够长，使得超快近红外脉冲能够通过称为电光采样的技术追踪其相对缓慢的振荡电场。通过比较入射到样品上并通过样品传输的时间分辨太赫兹脉冲，可以检索该材料的完整复杂介电响应。该信息还可以作为相对于同步激发泵脉冲的时间延迟的函数来提取，以执行超快太赫兹光谱并监测动态凝聚态物质系统。