Optical Parametric Oscillator (OPO)

实验室天体物理学小组(AG Schlemmer)开发了分子光谱学的新方法。为此使用了各种放射源。一个独特的研究领域涉及捕获的分子离子的作用光谱，这导致了在《科学》、《自然》、《自然化学》和《自然评论物理学》上发表文章。在所要求的CW OPO的帮助下，新的两种颜色实验成为可能。一种(现有的)颜色用于处理分子离子，以便它们与我们的离子捕获器中的母离子相区别的产物发生反应。由于在这些实验中只存储了有限的离子系综，因此可以确定反应离子和非反应离子的比例，并可以测量不同母体离子的支化比。因此，可以分离出结构异构体、构象异构体，甚至是核自旋异构体。通过第二种颜色，也可以在相同的实验中处理其他物种。因此，他们也离开了父母的合唱团。在一项有两个异构体的实验中，这可能会导致所有亲本物种从群体中消失。然而，当在光耗尽系综的两个周期之间的陷阱中添加中性碰撞伙伴时，将发生异构体转化，并不是所有的反应物分子都将转化。结果，可以确定用于这种转换处理的速率。这种基本的过程，例如通过化学反应的核自旋转换，对于从分子云中形成恒星的过程可能是至关重要的。这里提出的OPO将首次使此类实验成为可能。区分同分异构体是一个具有很大应用潜力的话题(分析)。两个颜色实验也将能够展开没有规则结构的软性分子的光谱，例如神秘的质子化甲烷分子。

The laboratory astrophysics group (AG Schlemmer) develops new methods of molecule spectroscopy. Various radiation sources are used for this purpose. One unique field of research concerns the action spectroscopy of trapped molecular ions which led to publications in Science, Nature, Nature Chemistry and Nature Review Physics. With the help of the requested cw OPO new two color experiments become possible. One (existing) color is used to address a molecular ion such that they are reacting to products which can be distinguished from the parent ion in our ion trap instruments. Since onle y finite ensemble of ions is stored in these experients the fraction of reacting ions and non-reacting ions can be determined and a branching ratio of different parent ions can be measured. Thus structural isomers, conformers and even nuclear spin isomers can be isolated. Via the second color also the other species can be addressed in the same experiment. So they leave the parent ensemble as well. In an experiment with two isomers this could lead to the loss of all parent species from the ensemble. However, when a neutral collision partner is added to the trap inbetween the periods when the light is depleting the ensemble, isomer conversion will happen and not all reactant molecules will be converted. As a result the rate for such a conversion process can be determined. Such fundamental processes, e.g., nuclear spin converion via chemical reactions, can be crucial for the process of star formation out of a molecular cloud. The OPO proposed here will make such experiments possible for the first time. Distinguishing isomers is a topic with large potential for applications (analytics). Two color experiments will also enable to unfold spectra of floppy molecules without a regular structure, e.g. the enigmatic protonated methane molecule.