OP: Transforming Table-top Soft X-Ray Lasers into High Average Power Devices

OP：将台式软 X 射线激光器转变为高平均功率设备

• 批准号: 1509925
• 负责人: Jorge Rocca
• 金额: $ 40万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1509925&HistoricalAwards=false
• 关键词: OP; Transforming; Table; top; Soft

Transforming Table-top Soft X-Ray Lasers into High Average Power DevicesAbstractNon-Technical: Recent advances in compact and more readily accessible "table-top" soft x-ray lasers based on plasma amplifiers are enabling nano-scale applications including ultra-high spatial resolution microscopy, the defect-free printing of nanostructures, the study of the electronic structure and reactivity of nano-clusters and molecules, and the development of chemically sensitive nano-probes that will be able to map the composition of nano-scale objects in 3-dimensions. While these lasers have the advantage of their compact size, their use in many applications is still limited by their low average power.The proposed research is designed to advance table-top soft x-ray lasers into high average power devices , with the goal of ultimately achieving multi-milliwatt average power laser beams in the 60-100 eV photon energy region from a compact device, greatly impacting applications in several fields. We plan to achieve a significant increase in average powers by tailoring the plasma amplifier with an unprecedented level of control to achieve higher efficiency while simultaneously increasing the repetition rate by using a new type of diode-pumped high energy ultra-short pulse laser driver.Technical: In the present state-of-the-art collisional soft x-ray lasers only several percent of the laser pump energy is deposited in the gain region. Recent experiments and simulations show that relatively minor alterations in the pump energy temporal distribution can result in a large increase in the soft x-ray laser efficiency. We propose to take advantage of this unexploited high sensitivity to significantly increase the efficiency and output power by tailoring the pump energy deposition rate with a high level of control to create a plasma with larger gain and reduced refraction loses. Extensive sets of hydrodynamic/atomic physics simulations and experiments covering a broad range of pump parameters will be conducted to identify the pump pulse sequence that maximizes the soft x-ray laser output energy. The resulting increase in the soft x-ray laser efficiency will be combined with an increase in repetition rate made possible by a novel high energy diode-pumped solid state laser driver. This could result in table-top soft x-ray laser beams with orders of magnitude higher average output powers in the 60-100 eV photon energy region than presently available compact coherent sources. The more efficient pumping will also facilitate the extension of practical soft x-ray lasers to shorter wavelengths.The transformation of compact soft x-ray lasers into high average power devices can be expected have a broad technology impact in nanoscale imaging, defect-free patterning of materials, and materials characterization. The propose research will provide exciting multi-disciplinary thesis projects for graduate students, with the opportunity of working in both the engineering and the physics of advanced laser systems. The proposed project will also contribute to train a diverse workforce of an area of great industrial interest and economic impact, as the semiconductor industry is approaching the start of the mass production of computer processors using extreme ultraviolet lithography. We plan to use the opportunities offered by the proposed project to involve a diverse group of undergraduates, high school students, and high school teachers in research. We plan to include the participation of high school students in the project during the summers.

将台式软X射线激光器转变为高平均功率器件非技术：基于等离子体放大器的紧凑型和更容易获得的“台式”软X射线激光器的最新进展使纳米级应用成为可能，包括超高空间分辨率显微镜、纳米结构的无缺陷打印、研究纳米团簇和分子的电子结构和反应性，以及开发能够绘制三维纳米级物体组成的化学灵敏纳米探测器。虽然这些激光器具有体积小的优势，但它们在许多应用中的使用仍然受到低平均功率的限制。拟议的研究旨在将台式软X射线激光器推进到高平均功率器件，目标是最终从紧凑的器件获得60-100 eV光子能区的多毫瓦平均功率激光，这将对几个领域的应用产生重大影响。我们计划通过对等离子体放大器进行前所未有的控制来显著提高平均功率，同时使用一种新型的二极管泵浦高能超短脉冲激光驱动器来提高重复频率。技术：在目前最先进的对撞式软X射线激光器中，只有百分之几的激光泵浦能量沉积在增益区。最近的实验和模拟表明，泵浦能量时间分布的相对较小的改变可以导致软X射线激光效率的大幅提高。我们建议利用这种尚未开发的高灵敏度，通过调整泵浦能量沉积速率和高水平的控制来显著提高效率和输出功率，以产生具有更大增益和更小折射损失的等离子体。将进行一系列广泛的流体力学/原子物理模拟和实验，涵盖广泛的泵浦参数，以确定使软X射线激光输出能量最大化的泵浦脉冲序列。由此产生的软X射线激光效率的提高将与由新型高能二极管泵浦的固态激光驱动器实现的重复频率的提高结合在一起。这可能导致桌面软X射线激光光束在60-100 eV光子能区的平均输出功率比目前可用的紧凑相干源高出数量级。更有效的泵浦也将有助于将实用的软X射线激光器扩展到更短的波长。可以预期，紧凑型软X射线激光器向高平均功率器件的转变将在纳米级成像、材料的无缺陷图案化和材料表征方面产生广泛的技术影响。这项拟议的研究将为研究生提供令人兴奋的多学科论文项目，并有机会在先进激光系统的工程和物理方面工作。拟议的项目还将有助于在一个具有重大工业利益和经济影响的领域培训多样化的劳动力，因为半导体行业即将开始使用极端紫外线光刻技术大规模生产计算机处理器。我们计划利用提议的项目提供的机会，让不同的本科生、高中生和高中教师参与研究。我们计划在暑假期间让高中生参与这个项目。