Ultrafast dynamics in complex systems

自1895年发现以来，X射线带来了对物质结构的新见解，这是以前用传统光学方法无法获得的。在过去的十年里，来自不同科学领域的研究人员正在等待X射线脉冲来探测高时间分辨率的动力学过程。这一探索推动了X射线自由电子激光设施的建设。除了巨额的初始财务投资(数十亿美元)外，它们的缺点是可获得性有限，限制了可能进行的实验的数量。*因此，对替代超短X射线源进行了密集的开发。近年来，我的团队利用先进激光光源(ALLS，位于INRS-ERMT)开发了频域光学参数放大器(FOPA)，这是一个国际上非常重视的概念。这种独特的桌面激光技术具有产生高亮度飞秒到阿秒脉冲的潜力，最高可达软X射线，并通过产生强烈的超短太赫兹脉冲得到电磁光谱的另一个极端的补充。*基于最近的进展，我的发现号研究计划旨在推动从太赫兹到软X射线的超快技术。通过组合这种宽频率范围内的脉冲，我的目标是拍摄分子和固体中动力学的完整电影。在接下来的五年里，我提出了一项雄心勃勃的计划，以应对超快科学和技术的三大挑战：*利用频域非线性光学技术，包括FOPA，用于高峰值功率红外和中红外激光脉冲，直到单周期脉冲持续时间，并利用它们产生高亮度软X射线，完全与超短THz脉冲同步。*通过探索大分子的结构和电子动力学，将这些独特的来源用于尚未探索的分子科学领域。特别是，由核心电子电离引发的分子中的超快化学反应将被成像，以获得与放射生物学领域相关的过程的基本了解。*研究先进材料中的超快动力学及其控制。我们将研究如何使用超短高场太赫兹脉冲来精确控制二氧化钒的光学性质，二氧化钒是一种非常有希望的材料，用于开发未来的信息和通信技术设备。*通过这些需要激光工程、物理、化学和材料科学方面的多学科专业知识的努力，我提议在未来五年内招募相当数量的年轻研究人员，培训10名实习生、2名硕士和8名博士生。这些受训人员将在ALL这一世界级激光设备中进行实验，并将加入各种国家、国际和行业合作。

Since there discovery in 1895, X-rays have led to new insight on the structure of matter, previously inaccessible with conventional optical methods. Over the last decade, researchers from a broad diversity of scientific horizons are awaiting X-ray pulses to probe dynamical processes with high temporal resolution. This quest motivates the construction of X-ray Free Electron Laser facilities. Their drawback besides a huge initial financial investment (billions of dollars) is limited availability, restraining the number of possible experiments. ******Thus, intense development on alternative ultrashort X-ray sources is undertaken. Over the recent years, my team has capitalized on access to the Advanced Laser Light Source (ALLS, located at INRS-ÉMT) to develop the Frequency domain Optical Parametric Amplifier (FOPA), a concept internationally valued. This unique table-top laser technology bears the potential to generate high brightness femto- to attosecond pulses up to the soft X-rays, complemented by the other extreme of the electromagnetic spectrum through the generation of intense ultrashort THz pulses. ******Founded on this recent progress, my Discovery research program aims to push ultrafast technologies, from the THz to the soft X-rays. By combining pulses within this wide range of frequencies, my goal is to shoot complete movies of dynamics in molecules and solids. Over the next five years, I propose an ambitious program to address three major challenges of ultrafast science and technologies:****** To capitalize on Frequency domain Nonlinear Optical Technologies including FOPA for high peak power infrared and mid-infrared laser pulses, down to single-cycle pulse duration, and to use them for generating high brightness soft X-rays, fully synchronized to intense ultrashort THz pulses.****** To exploit these unique sources for yet unexplored fields of molecular science by probing structural and electronic dynamics in large molecules. In particular, ultrafast chemical reactions in molecules, triggered by the ionization of core electrons will be imaged to gain fundamental understanding of processes relevant to the field of radiobiology.****** To investigate ultrafast dynamics and its control in advanced materials. We will study how ultrashort high-field THz pulses can be used to control precisely the optical properties of vanadium dioxide, a highly promising material for the development of future devices for information and communication technologies.******Through these efforts that require multidisciplinary expertise in laser engineering, physics, chemistry, and material science, I propose to enrol a critical mass of young researchers with the training of 10 internships, 2 M.Sc., and 8 Ph.D. students over the next five years. These trainees will perform their experiments at ALLS, a world-class laser facility, and will join various national, international, and industrial collaborations.