A broadly tunable quantum cascade laser for spectroscopic characterization

用于光谱表征的广泛可调量子级联激光器

• 批准号: 359431-2008
• 负责人: Xu, Yunjie
• 金额: $ 3.5万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366423
• 关键词: broadly; tunable; quantum; cascade; laser

Water plays an active role in stabilizing biological structures and facilitating biological functions. Significant current research efforts are directed toward determining absolute configurations of biomolecules in their (natural) aqueous environment. To achieve this ultimate goal, it is essential to develop an adequate theoretical description of solvation of chiral molecules in aqueous solution.While the solution phase measurements provide information on the combined effects of an enormous amount of intra- and intermolecular hydrogen bonding in solution, it is extremely difficult, if not impossible, to uncover the underlying mechanisms without detailed and accurate experimental input on the molecular level. One of our approaches to tackle this challenge is to apply jet-cooled high resolution infrared laser spectroscopy to characterize the stepwise solvation of a chiral molecule by several water molecules. Studies of these model molecular systems in a well controlled molecular beam environment will allow us to assess the influence of various effects separately. Such a stepwise approach will be extremely valuable for developing a new theoretical description of solvation.A monumental milestone was reached recently in quantum cascade laser (QCL) development with the realization of continuous wave external cavity QCLs that have wide frequency tunability, narrow line width, excellent output power, and super mode quality. These key characters make them an ideal laser source for high resolution infrared laser spectroscopy. We will take advantage of this timely development and implement such a QCL into our recently completed cavity enhanced absorption spectrometer. Funds are requested to purchase an external cavity QCl and a pair of cavity ring down mirrors centred at 6.2µm region. These are two essential components that we need for the spectroscopic characterization of the chiral molecule-(water)_n clusters.

水在稳定生物结构和促进生物功能方面发挥着积极作用。当前的重要研究工作旨在确定生物分子在（天然）水环境中的绝对构型。为了实现这一最终目标，必须对水溶液中手性分子的溶剂化进行充分的理论描述。虽然溶液相测量提供了有关溶液中大量分子内和分子间氢键的综合影响的信息，但如果没有分子水平上详细而准确的实验输入，要揭示潜在的机制是极其困难的，如果不是不可能的话。我们应对这一挑战的方法之一是应用喷射冷却高分辨率红外激光光谱来表征手性分子被多个水分子逐步溶剂化的过程。在良好控制的分子束环境中研究这些模型分子系统将使我们能够分别评估各种效应的影响。这种逐步的方法对于开发新的溶剂化理论描述非常有价值。最近，量子级联激光器（QCL）的发展达到了一个里程碑，实现了具有宽频率可调性、窄线宽、出色的输出功率和超模质量的连续波外腔QCL。这些关键特性使其成为高分辨率红外激光光谱的理想激光源。我们将利用这一及时的开发成果，并将这种 QCL 应用于我们最近完成的腔增强吸收光谱仪中。需要资金购买一个外腔 QCl 和一对以 6.2μm 区域为中心的腔衰荡镜。这是我们对手性分子（水）_n 簇进行光谱表征所需的两个基本组成部分。