Dual-Comb Spectroscopy Instrument for Remote Sensing

原子和分子物理学中的现代量子技术以及量子光学使环境测量达到了一个新的灵敏度和分辨率水平，从而为可持续资源利用和有效可验证的气候保护创造了知识基础。不同的方法已经找到了自己的方式，从用于调查基础科学问题到应用于环境物理学。在海德堡，我们已经迈出了从量子气体实验中的单粒子检测到单原子水平的痕量分析的一步，用于环境科学中相关的水和冰的年代测定。有了这个建议，我们希望在量子光学领域进行另一个步骤，即转移技术，这些技术尚未处于直接用于遥感的商业阶段，即双梳光谱。近年来，双梳状光谱（DCS）已被证明适用于遥感，我们希望将该方法应用于海德堡最先进的傅里叶变换光谱并对其进行基准测试。在这里，我们申请了一个光谱设置，允许进入这项技术的第一步，并为海德堡的一个新的研究方向奠定了基础。该项目将由量子光学（Oberthaler教授）和环境物理与遥感（Butz教授）领域的专家组成的团队推进。该仪器将由两个高度可控的超稳定频率梳装置组成，并将锁定在绝对频率标准上，以确保相互相干。这是将光谱特性从光域转移到射频域的先决条件，可以用单个、快速和灵敏的光子探测器直接检测。该装置的性能将在实验室中使用参考气体样本进行持续监测，这也将用于探索新的检测方案，以优化某些分子物种的信噪比。对于遥感，光输出将被转移到海德堡市上空的一个长开放路径装置，在那里必须安装特殊的护理和调整，以确保双梳状光谱的最佳性能。有了额外的光谱控制水平，将实现对特定分子的最高灵敏度，并将作为未来专门设计的激光系统的测试案例，在环境物理的不同监测和检测活动中寻找应用。双梳装置将作为进一步发展的基础，最终将导致基于量子光学技术的遥感建设的质量达到一个新的水平。

Modern quantum technologies in atomic and molecular physics as well as quantum optics enable measurements in the environment at a new level of sensitivity and resolution, thus creating a knowledge base for sustainable resource use and effective and verifiable climate protection. Different methods have already found their way from being used in the context of investigating fundamental science questions to application in environmental physics. In Heidelberg we have already undertaken the step from single particle detection in quantum gas experiments to trace analysis at single atom level for dating of water and ice relevant in environmental science. With this proposal, we would like to undertake another step of transferring knowhow in the quantum optics community which is not yet at the stage of being directly commercially available for remote sensing i.e. dual comb spectroscopy. In recent years it has been demonstrated that dual comb spectroscopy (DCS) is applicable to remote sensing and we would like to apply and benchmark this method with state-of-the-art Fourier-transform spectroscopy available in Heidelberg. Here, we apply for a spectroscopy setup which allows for the first steps of entering in this technology and with that setting the stage for a new research direction in Heidelberg. This project will be pushed forward by a team of experts in the field of quantum optics (Prof. Oberthaler) and environmental physics and remote sensing (Prof. Butz). The instrument will consist of two ultra-stable frequency comb setups which are highly controlled and shall be locked to an absolute frequency standard to ensure mutual coherence. This is the prerequisite for transferring the spectral properties from the optical domain to the radio frequency domain directly detected with a single, fast and sensitive photon detector. The performance of the setup will be constantly monitored with a reference gas sample in the lab, which will also be used to explore new detection schemes to optimize signal to noise for certain molecular species. For remote sensing, the light output will be transferred to a long open-path setup over the city of Heidelberg, where special care and adaptions have to be installed to ensure the optimal performance of the dual comb spectroscopy. With the additional level of spectral control, the highest sensitivity for specific molecules will be implemented and will act as a test case for future specifically designed laser systems finding application in different monitoring and detecting campaigns in environmental physics. The dual-comb setup will act as the basis for further developments which ultimately will lead to a new level of quality of remote sensing building on quantum optical techniques.