MRI: Development of a high energy, ultrabroadband, ultrashort infrared laser source

获得由化学研究仪器和设施(CRIF)计划共同资助的化学专业研究仪器(MRI)计划颁发的这一奖项，坦普尔大学的Eric Borguet教授将与他的同事Hai-Long Dai、Robert Stanley和Robert Levis合作开发一种仪器，通过泵浦AgGaS2和AgGaSe2等非线性光学材料，能够作为波长超过2500 nm的超短红外(IR)脉冲的高能超宽带源。这个新系统将产生阿秒脉冲，可以实时研究电子在原子和分子中的运动。这种中红外脉冲激光光源将为探索材料、生物分子和化学反应打开一扇窗。该系统将建立在现有技术的基础上，包括非共线光学参数放大(NOPA)。这一新的光源将允许研究人员进行新类型的非线性实验，如多维红外光谱和界面敏感振动和频率光谱。强烈的中红外光子将高次谐波产生(HHG)过程中的截止能量扩展到更深的X射线区域。该建议旨在加强各级的研究和教育，特别是在下列领域：(A)界面的非线性光学光谱；(B)多维红外光谱；(C)胶体界面的和频产生振动光谱；(D)光生物过程的超宽带红外光谱；(E)红外脉冲成丝；(F)通过振动激发进行相干控制；以及(G)作为高次谐波产生驱动器的长波超短脉冲源。这是十亿分之一秒。客观地说，一阿秒相当于一秒，就像一秒相当于大约320亿年。这种类型的光可以直接激发分子的振动运动，并随后将这种能量分配到材料中。这项技术推动了超快激光技术的发展。随着磁场的增长，分子现象在阿秒和更短的时间尺度上的意义正在被认识到。可以说，化学中的一些最基本的过程(例如，键的断裂和形成、电子转移等)发生在这些超快的时间尺度上。这项开发工作将创造一种具有高度通用性的新仪器，将用于不断增长的超快光谱领域。该仪器是一个项目的一部分，该项目旨在开发强大的超快光谱能力，以刺激一些研究项目，并为与同事的合作提供基础。这些独特的属性表明，新的文书将在许多领域具有广泛的适用性。在仪器的开发、建造、测试和调试过程中，许多学生将参与其中。这将在不断发展的超快方法学领域提供丰富的培训经验，同时允许研究不稳定的反应产物或分子的激发状态，同时结合光谱学(提供结构信息)和动力学(揭示反应事件的细节)来确定它们的结构。

With this award from the Chemistry Major Research Instrumentation (MRI) Program that is co-funded by the Chemistry Research Instrumentation and Facilities (CRIF) Program, Professor Eric Borguet from Temple University in collaboration with his colleagues Hai-Lung Dai, Robert Stanley and Robert Levis will develop an instrument capable of acting as a high energy, ultrabroadband source of ultrashort infrared (IR) pulses at wavelengths beyond 2500 nm by pumping nonlinear optical materials such as AgGaS2 and AgGaSe2. This new system will produce attosecond pulses that will allow study of electron motions in atoms and molecules in real time. This mid-infrared pulsed laser source will open a window for exploration of materials, biomolecules and chemical reactions. The system will build upon existing techniques including non-collinear optical parameter amplification (NOPA). This new source will allow researchers to do new types of nonlinear experiments such as mutidimensional IR spectroscopy and interface sensitive vibrational sum frequency spectroscopy. Intense mid-IR photons will extend the cut-off energy in high-harmonic generation (HHG) processes deeper into the X-ray region. The proposal is aimed at enhancing research and education at all levels, especially in areas such as (a) nonlinear optical spectroscopy of interfaces; (b) multidimensional infrared spectroscopy; (c) sum frequency generation vibrational spectroscopy of colloid interfaces; (d) ultrabroadband infrared spectroscopy of photobiological processes; (e) filamentation with IR pulses; (f) coherent control via vibrational excitation; and (g) long-wavelength ultrashort pulse sources as a driver of high-harmonic generation.The laser system to be developed will generate electromagnetic radiation, light, in the infrared region of extremely short duration, attoseconds. This is one quintillionth of a second. To put this into perspective, an attosecond is to a second, what a second is to about 32 billion years. This type of light can directly excite the vibrational motion of molecules and the subsequent distribution of this energy into a material. This technique advances ultrafast laser technology. As the field grows, the significance of molecular phenomena on time scales of attoseconds and shorter is being realized. Arguably, some of the most fundamental processes in chemistry (e.g., bond breaking and formation, electron transfer, and others) occur on these ultrafast time scales. This development effort will create a new instrument with high versatility that will be used in the growing field of ultrafast spectroscopy. The instrument is part of a program to develop a strong ultrafast spectroscopic capability to stimulate a number of research programs as well as to provide a base for collaborations with colleagues. These unique attributes indicate that the new instrument will have broad applicability across many fields. During development, construction, testing and commissioning of the instrument many students will participate. This will provide a rich training experience in the growing field of ultrafast methodology while allowing study of unstable reaction products or excited states of molecules, and at the same time determining their structure while combining spectroscopy (giving structural information) and dynamics (revealing details of the reactive events).