Excitation of Molecules by Strong Laser Fields

了解光如何与物质相互作用在科学研究和应用中很重要。例如，自然界中最重要的过程之一是植物在光合作用中吸收太阳能。科学家使用激光制造具有特殊性质的光形式，用于研究和光通信等技术。该项目支持的研究将调查极强的激光如何与小分子相互作用。我们将深入了解三个主要领域。1)当分子与强激光相互作用时，分子可以反过来产生具有独特性质的新型辐射。在这种情况下，产生的光可以具有非常短的波长和非常短的时间持续时间。这些性质可用于研究非常快的过程，如化学反应。2)强激光可以驱动分子中的过程，使人们能够更多地了解分子结构。3)强激光可以用来控制分子的振动运动，这是用于存储和传递能量的分子的特性之一。通过控制分子振动，人们将从根本上更好地理解分子中的能量传递。4)这些实验中使用的技术和仪器为学生提供了极好的培训，使他们能够获得在许多工业和研究实验室中使用的技能。本项目特别关注在分子中引起激发的强场过程。虽然强场对分子的激发是无处不在的，但与其他强场物理领域相比，关于这方面的实验和理论工作几乎没有那么多。此外，激发的可能机制的范围在很大程度上仍未被探索。然而，人们对这一领域的兴趣与日俱增，因为激发的一种途径涉及到内轨道电离。事实证明，这种激发可以如此显著，以至于它可以通过强激光束丝在大气中导致激光。然而，氮气中反转形成的确切过程仍然不完全清楚。所有这些目标的共同主题是理解强激光场对分子的激发，以及这种激发对核间分离的依赖。这些实验的成功结果应该会大大扩展对强光如何与物质相互作用的理解，特别是关于分子结构和动力学的理解。

Understanding how light interacts with matter is important in scientific research and applications. For example, one of the most vital processes in nature is the absorption of solar energy by plants in photosynthesis. Scientists use lasers to make forms of light with special properties that are used in research and technologies such as optical communications. The research supported in this project will investigate how extremely intense laser light interacts with small molecules. Insight will be gained into three main areas. 1) When molecules interact with intense laser light, the molecules can, in turn, generate new types of radiation with unique properties. In this case, the generated light can have very short wavelengths and very short durations in time. These properties can be used to study very fast processes such as chemical reactions. 2) Intense laser light can drive processes in molecules in a way that allows more to be learned about the structure of molecules. 3) Intense laser light can be used to control the vibrational motions of molecules, which is one of the properties of molecules used for storing and transferring energy. Energy transfer in molecules will be better understood at the fundamental level by controlling molecular vibrations. 4) The techniques and instrumentation used in these experiments provide excellent training for students to acquire skills used in many industries and research laboratories.This project focuses specifically on strong field processes that give rise to excitation in molecules. Although the excitation of molecules by strong fields is ubiquitous, there is not nearly as much experimental and theoretical work on this compared to other areas of strong field physics. Moreover, the range of possible mechanisms for excitation remains largely unexplored. However, there is increasing interest in this field, as one pathway to excitation involves inner orbital ionization. It turns out that excitation can be so significant that it can lead to lasing in the atmosphere by intense laser beam filaments. Nevertheless, the exact process by which inversions are formed in nitrogen is still not fully understood. The common theme to all of these goals is to understand the excitation of molecules by strong laser fields and the dependence of this excitation on internuclear separation. Successful outcomes of these experiments should greatly expand the understanding of how intense light interacts with matter, particularly regarding molecular structure and dynamics.