Probing Intermolecular Dynamics with Nonlinear Ultrafast THz Spectroscopy

用非线性超快太赫兹光谱探测分子间动力学

• 批准号: 2316042
• 负责人: Geoffrey Blake
• 金额: $ 53.5万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2316042&HistoricalAwards=false
• 关键词: Probing; Intermolecular; Dynamics; Nonlinear; Ultrafast

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) program in the Division of Chemistry, Geoffrey Blake and Scott Cushing of the California Institute of Technology (Caltech) are developing sophisticated spectroscopies to study the structure and dynamics of liquids and liquid mixtures. The forces between molecules that determine the properties of liquid water, for example, can be directly probed only using light that is much lower frequency than that of visible light, on the order of a few terahertz (THz). Still, the motions in liquids are very fast, and a significant technical challenge is to develop very short, yet tailored, pulses of THz light. Drs. Blake and Cushing and their students will advance ultrafast nonlinear THz spectroscopies to study the intermolecular forces in hydrogen bonding liquids (e.g., water) in the presence of dissolved ions. Their discoveries could lead to new THz methodologies that advance applications in sustainable energy, telecommunications, and national security. The project will provide a highly interdisciplinary environment that includes graduate students and undergraduates, not only from Caltech but from nearby minority/Hispanic serving institutions, lowering the barriers for entry into quantum science.Direct probes of intermolecular forces in liquids and other molecular materials, especially those involving hydrogen bonds, require THz photons, yet the necessary time resolution is sub-picosecond. Thus, multi-octave pulses with controllable frequency and carrier envelope phase content must be generated. This collaborative Caltech team will combine the near-IR/Visible pulse compression expertise in the Cushing group with novel THz emitters fabricated at Caltech to drive pump-probe and THz-THz-Raman (TTR) approaches pioneered in the Blake group into the 10-30 femtosecond regime. The principal scientific focus will be studies of the hydrogen bond dynamics in liquid water and mixtures, especially at high ionic strength and with components such as alcohols that demonstrate unusual thermodynamics of mixing. The broader scientific applications of the tailored THz pulse capabilities include the selective nonlinear studies of a broad range of processes in sustainable energy generation and storage, and in quantum information science.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.

在化学系化学结构、动力学和机理 A (CSDM-A) 项目的支持下，加州理工学院 (Caltech) 的杰弗里·布莱克 (Geoffrey Blake) 和斯科特·库欣 (Scott Cushing) 正在开发复杂的光谱学来研究液体和液体混合物。例如，决定液态水性质的分子之间的力只能使用比可见光频率低得多的光直接探测，约为几个太赫兹（THz）。尽管如此，液体中的运动仍然非常快，一个重大的技术挑战是开发非常短但定制的太赫兹光脉冲。博士。布莱克和库欣以及他们的学生将推进超快非线性太赫兹光谱，以研究溶解离子存在下氢键液体（例如水）中的分子间力。他们的发现可能会带来新的太赫兹方法，从而推动可持续能源、电信和国家安全领域的应用。该项目将提供一个高度跨学科的环境，包括研究生和本科生，不仅来自加州理工学院，还包括来自附近少数族裔/西班牙裔服务机构的研究生和本科生，降低进入量子科学的门槛。直接探测液体和其他分子材料中的分子间力，特别是涉及氢键的那些需要太赫兹光子，但所需的时间分辨率是亚皮秒。因此，必须生成具有可控频率和载波包络相位内容的多倍频程脉冲。这个加州理工学院的合作团队将把库欣小组的近红外/可见光脉冲压缩专业知识与加州理工学院制造的新型太赫兹发射器结合起来，以推动布莱克小组首创的泵浦探针和太赫兹-太赫兹-拉曼（TTR）方法进入10- 30飞秒制度。主要的科学重点将是研究液态水和混合物中的氢键动力学，特别是在高离子强度和醇等成分的情况下，这些成分表现出不寻常的混合热力学。定制太赫兹脉冲功能的更广泛的科学应用包括对可持续能源生成和存储以及量子信息科学中广泛过程的选择性非线性研究。该奖项反映了 NSF 的法定使命，并通过使用评估结果被认为值得支持。基金会的智力价值和更广泛的影响审查标准。