Extreme THz Science with Ultra-Intense Laser Induced Plasma

太赫兹频段(0.3-10太赫兹)一直被认为是电磁频谱中最后的科学空白。由于小规模电子加速器、非接触探头、高场非线性光学和宽带材料表征等多种原因，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，对太赫兹科学技术的研究一直局限于可获得的纳米焦耳到毫焦耳激光脉冲能量的边际功率水平。该项目是基础科学探索、应用设备创新，以及超强激光脉冲极端太赫兹科学的初步试验。大于kJ的激光脉冲能量和小于1ps的激光脉冲持续时间用于太赫兹科学在世界上任何地方都找不到。Pi在激光能量学实验室的初步实验使用了一台多太瓦的激光(脉冲能量为10J，脉冲宽度为1ps)和欧米茄-EP激光(脉冲能量为200J，脉冲宽度为亚ps)来产生微等离子体，并在中间试验中测量了不同激光条件下的太赫兹波产生。PI将通过使用独特的激光(从J到kJ脉冲能量)产生和检测太赫兹波来研究极端的太赫兹科学。建议的超强太赫兹光源将为各种光-物质相互作用应用打开大门。国际和平研究所建议利用最初为大学激光能量实验室的激光聚变而建造的最强激光(千焦耳脉冲能量和ps脉冲宽度)来探索极端太赫兹波科学。罗切斯特的。目标是实现世界上最强的太赫兹源，并研究使用单周期太赫兹脉冲的非线性科学。单次激发时空太赫兹辐射测量将是超强太赫兹光子学的第一个关键发展。拟议的任务包括研究不同目标材料(包括不同原子序数的元素以及有机材料)产生太赫兹波、脉冲激光参数(脉冲宽度、激光波长、光学偏振和功率密度)以及光谱/时间分辨率测量。对于超强激光(两次激光之间的等待时间通常为40分钟或更长)，开发单次THz表征技术势在必行，这也将在我们的实验室进行演示。我们开发的太赫兹光子学项目使跨学科研究成为可能，并推动了大量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理解、发明和过程，并产生广泛的科学影响。由于追求太赫兹科学的进步涉及广泛的跨学科研究，该项目将继续提供极好的合作机会，促进具有不同社会经济背景的学生和代表性不足的群体之间的教学、培训和学习。研究团队将有一名来自少数族裔群体的博士生。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.