Excellence in Research: Seeding Stimulated Raman Backscattering with Intense and Ultra-Intense Laser Pulses

实现高峰值强度和极高功率的激光脉冲处于激光发展的前沿。为提高激光功率而不断调整的比例很快就会达到固态材料损伤阈值所规定的极限；等离子体可以提供另一种激光增益介质，有可能使激光功率达到非凡的水平。该项目提供了一个模拟驱动的发现和实验验证平台，以实现以等离子体为放大介质的下一级高激光强度。这代表着长达十年的研究工作取得了新的进展，目的是了解激光等离子体过程背后的丰富物理学原理，以及产生高功率、超短激光脉冲的过程。该项目将有助于提高特拉华州立大学在STEM方面的研究能力，并将有助于在特拉华州立大学建立超快科学和等离子体物理交界处的核心研究基础设施。该项目涉及激光物理和工程、等离子体物理和计算物理，涉及多学科性质，将为来自服务不足社区的研究生和本科生带来独特的教育和培训机会。该项目的目标是建立一个坚实的理论理解，并模拟和测试等离子体中受激拉曼背散射(SRBS)方案的稳健性，通过该方案在等离子体通道中产生相干的、超短、超强的激光脉冲。这种SRBS方案旨在克服以往工作中面临的饱和障碍，这限制了转换效率和最大放大种子能量。以仿真为指导，揭示方案的全部容量和方案中的物理机制。在实验上，将使用强和超强输入种子脉冲对该方案进行详细研究。超强脉冲的放大和压缩为超快和等离子体科学研究提供了令人兴奋的新现象。产生的超短、超强的SRBS脉冲将为产生阿秒脉冲和水窗X射线激光开辟新的和独特的机会。这项工作将通过理论、计算和实验的综合小组努力进行，依靠特拉华州立大学以及普林斯顿大学和劳伦斯·利弗莫尔国家实验室的合作伙伴的联合专业知识。该项目由物理学部管理，并由历史上的黑人学院和大学卓越研究计划和既定的激励竞争研究计划(EPSCoR)共同资助。该奖项反映了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。

Achieving high peak intensity and extreme power of laser pulses stands on the leading edge of laser developments. The continued scaling of lasers to increase power will soon reach the limits dictated by the damage threshold of solid state materials; plasmas can provide an alternative laser gain medium, potentially allowing laser power to reach extraordinary levels. This project provides a simulation-driven discovery and experimental verification platform to achieve the next level of high laser intensity using plasma as the amplification medium. This represents a new advance in decade-long research efforts to understand the rich physics behind laser-plasma processes and the production of high-power, ultra-short laser pulses. This project will contribute to increasing the research capacity of Delaware State University (DSU) in STEM and will help to build the core infrastructure in research at the interface of ultrafast science and plasma physics at DSU. The multi-disciplinary nature of the project, involving laser physics and engineering, plasma physics, and computational physics, will bring unique education and training opportunities to graduate and undergraduate students from under-served communities. The collaborations within DSU and other institutions will also offer the students a chance to work with world-class scientists.The goal of this project is to develop a solid theoretical understanding and to simulate and test the robustness of a Stimulated Raman Back Scattering (SRBS) scheme in plasma, through which a coherent, ultrashort, ultra-intense laser pulse is generated in a plasma channel. This SRBS scheme aims to overcome the saturation barrier faced in previous efforts, which limits the conversion efficiency and the maximum amplified seed energy. Using simulations as the guide, the full capacity of the scheme and the physical mechanisms in the scheme will be revealed and explored. Experimentally, the scheme will be investigated in detail using intense and ultra-intense input seed pulses. The amplification and compression of the ultra-intense pulse provides exciting and new phenomena in ultrafast and plasma science research. The generated ultrashort, ultra-intense SRBS pulse will open up new and unique opportunities for generating atto-second pulses, and water-window x-ray lasers. The work will be carried out through integrated group efforts of theory, computation, and experiment relying on joint expertise from Delaware State University and partners at Princeton University and Lawrence Livermore National Laboratory. This project is managed by the Division of Physics and jointly funded by the Historically Black Colleges and Universities Excellence in Research Program and the Established Program to Stimulate Competitive Research (EPSCoR).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.