Extreme THz Science with Ultra-Intense Laser Induced Plasma

太赫兹频段（0.3 - 10太赫兹）一直被认为是电磁波谱中最后一个科学空白。由于各种原因，包括小型电子加速器、非接触式探针、高场非线性光学和宽带材料表征，该领域显示出巨大的前景。自20世纪80年代末在光导体和电光晶体上使用短脉冲激光激发以来，太赫兹科学技术的研究一直局限于纳米焦耳到mJ激光脉冲能量的可用激光器的边际功率水平。该项目是超强激光脉冲极端太赫兹科学的基础科学探索、应用器件创新和先导试验。在世界上任何地方都没有超过kJ的激光脉冲能量和小于1ps的激光脉冲时间用于太赫兹科学。PI在激光能量学实验室的初步实验使用多太瓦激光器（10 J脉冲能量和1 ps脉冲持续时间）和Omega-EP激光器（200 J脉冲能量和亚ps脉冲持续时间）产生微等离子体，并在中试过程中测量了不同激光条件下太赫兹波的产生。PI将研究极端太赫兹科学，通过使用独特的激光器（从J到kJ脉冲能量）产生和探测太赫兹波。提出的超强太赫兹源将为各种各样的光-物质相互作用应用打开大门。PI计划利用最初在罗切斯特大学激光能量学实验室为激光聚变建造的最强激光器（kJ脉冲能量和ps脉冲持续时间）来探索极端太赫兹波科学。目标是获得世界上最强烈的太赫兹源，并研究单周期太赫兹脉冲的非线性科学。单次太赫兹时空发射测量将是超强太赫兹光子学的第一个关键发展。提出的任务包括研究不同目标材料（包括不同原子序数的元素和有机材料）产生太赫兹波，脉冲激光参数（脉冲持续时间、激光波长、光偏振和功率密度），以及光谱/时间分辨测量。单次发射太赫兹表征技术的发展对于超强激光（激光发射之间的等待时间通常为40分钟或更长）是必不可少的，这也将在我们的实验室中进行演示。我们的太赫兹光子学项目的发展使跨学科研究和推进了许多太赫兹波传感和光谱学的发展。如果这项研究成功，这项高风险的研究可能会带来新的认识、发明和具有广泛科学影响的过程。由于太赫兹科学的进步涉及广泛的跨学科研究，该项目将继续提供良好的合作机会，以促进不同社会经济背景和代表性不足群体的学生的教学，培训和学习。研究团队将有一名来自少数族裔的博士生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The region of THz frequency band (0.3 – 10 THz) has long been considered the last remaining scientific gap in the electromagnetic spectrum. This field shows great promise for a variety of reasons including small-scale electron accelerators, contact-less probes, high-field nonlinear optics, and broadband material characterization. Since the use of short-pulse laser excitation on the photoconductors and the electro-optic crystals in late 1980s’, the research of THz science and technology has been limited to the marginal power level of available lasers with nano-Joule to mJ laser pulse energy. The project is basic scientific exploration, applied device innovation, and a pilot test for the extreme THz science with ultra-intense laser pulses. Greater than kJ laser pulse energy with less than 1 ps laser pulse duration for the THz science is not available anywhere in the world. PI’s preliminary experiment in the Laboratory for Laser Energetics used a multi-terawatt laser (10 J pulse energy and 1 ps pulse duration) and the Omega-EP laser (200 J pulse energy and sub-ps pulse duration) to create micro-plasma and measured THz wave generation under different laser condition during the pilot test. PI will investigate extreme THz science with THz wave generation and detection by using unique lasers (from J to kJ pulse energy). The proposed ultra-intense THz source will open the doors for a large variety of light-matter interaction applications.PI proposes to explore extreme THz wave science with the application of the most intense lasers ( kJ pulse energy and ps pulse duration) originally constructed for laser fusion at the Laboratory for Laser Energetics, Univ. of Rochester. The goal is to achieve the most intense THz sources in the world, and study nonlinear sciences with single cycle THz pulses. Single-shot spatiotemporal THz emission measurement would be the first critical development for the ultra-intense THz photonics. Proposed tasks including study of THz wave generation from different target materials (including elements with different atomic numbers as well as organic materials), pulsed laser parameters (pulse duration, laser wavelength, optical polarization, and power density), and spectral/temporally resolved measurement. The development of a single-shot THz characterization technology is imperative for the ultra-intense lasers (waiting time between the laser shot is often at 40 minutes or longer), which will also be demonstrated in our lab. Our development of the THz photonics project enables interdisciplinary research and advances numerous THz wave sensing and spectroscopy developments. If this is successful, this high-risk study may lead to new understanding, inventions, and processes with broad scientific impact. As the pursuit of progress in THz science involves extensive interdisciplinary research, this project will continue to provide excellent collaborative opportunities in the promotion of teaching, training, and learning among students with diverse socioeconomic backgrounds and within underrepresented groups. The research team will have one PhD student from an underrepresented minority group.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.