Widely Tunable Cavity-Enhanced Ultrafast Spectroscopy and the Dynamics of Hydrogen Bond Networks

在化学系化学测量和成像计划的支持下，埃里森教授和他在石溪大学的研究小组进一步开发了一种用于记录气体分子行为的新型光谱仪。特别是，艾利森教授记录了当几个水分子粘在一起形成一个环，但以其他方式与环境隔离时，水分子之间氢键振动的快照。这些简单系统的快照有助于理解在液态水等更复杂的网络中氢原子的运动是如何相互耦合的。这些信息使科学家能够对氢键物质建立更好的计算机模型。艾利森实验室开发的新超快光谱仪将能够记录比目前可能的更多稀薄样品的信号。艾利森教授的技术一旦被开发出来，就可以用来研究其他分子系统的运动，并在基础和应用研究中找到许多用途。例如，开发的技术可以让科学家研究水分子如何相互作用，以了解云是如何形成的，或者研究蛋白质分子如何与周围的分子相互作用，以了解生物过程中的酶功能。艾利森教授在这项研究中与研究生和本科生密切合作。他还参加了校园里一个针对高中生的学校暑期计划。超快光谱学方法，如瞬时吸收光谱学和二维光谱学，被广泛应用于许多学科。然而，这些技术通常仅限于光学厚度的样品，如固体和液体溶液。艾利森教授和他的团队致力于研制一种可广泛调谐的腔增强型超快光谱仪，并将其应用于基本氢键网络的动力学研究。这涉及到大量的仪器开发，同时对喷射冷却的气相分子和团簇进行了一系列实验。腔增强二维红外光谱(CE-2DIR)是研究氢键羧酸二聚体的另一种技术。对小的氚水团簇的研究将为理解和模拟液态水的复杂性提供关键数据。可广泛调谐的腔增强型超快光谱仪的发展有望为许多未来的应用提供新的机会，在这些应用中，经典的超快光谱已经受到其灵敏度和光谱信息的限制。该项目为参与该项目的学生提供了一个跨学科的研究机会。艾利森教授还参与了该大学的激光教学中心，为高中生和普通公众提供服务。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Professor Allison and his research group at Stony Brook University further develop a new type of spectrometer for recording the behavior of gas molecules. In particular, Professor Allison records snapshots of the vibrations of hydrogen bonds between water molecules when a few water molecules stick together in a ring but are otherwise isolated from the environment. These snapshots of simple systems help to understand how the motions of hydrogen atoms in more complex networks such as liquid water are coupled to one another. The information allows scientists to make better computer models of hydrogen-bonded matter. The new ultrafast spectrometers developed by the Allison Lab will be able to record signals from much more dilute samples than currently possible. Professor Allison's techniques, once developed, can be used to study motions of other molecular systems and find many uses in fundamental and applied research. For example, the developed technique could allow scientists to study how water molecules interact with each other to understand how clouds form or to study how protein molecules interact with their surrounding molecules to understand enzymatic functions in biological processes.Professor Allison works with graduate and undergraduate students closely in the research. He also participates in a school summer program on campus targeting high school students. Ultrafast optical spectroscopy methods, such as transient absorption spectroscopy and two-dimensional spectroscopy, are widely used across many disciplines. However, these techniques have been typically restricted to optically thick samples, such as solids and liquid solutions. Professor Allison and his group work on a widely tunable cavity-enhanced ultrafast spectrometer and apply it to the dynamics of elementary hydrogen bond networks. This involves substantial instrument development in concert with a series of experiments on jet-cooled gas-phase molecules and clusters. Cavity-enhanced two-dimensional infrared (CE-2DIR) spectroscopy is another technique to be developed to study hydrogen-bonded carboxylic acid dimers. The study of small deuterated water clusters will provide critical data for understanding and modeling the complexities of liquid water. The development of a widely tunable cavity-enhanced ultrafast spectrometer is expected to open new opportunities for many future applications where classic ultrafast spectroscopy has been limited by its sensitivity and spectral information. The project provides students involved in the project with an interdisciplinary research opportunity. Professor Allison also participates in the University's laser teaching center for the outreach to high school students and general publics.