The highly energetic photons of ultraviolet light drive electronic and rovibronic transitions in all molecular species. This radiation is thus a prime tool for strongly selective spectroscopic fingerprinting and real-time environmental monitoring if broad spectral coverage, short acquisition times, and high spectral resolution are achieved–requirements that are in mutual competition in traditional applications. As an approach with intrinsic potency in all three aspects, here we introduce ultraviolet dual comb spectroscopy using two broadband ultraviolet frequency combs centered at 871 THz and covering a spectral bandwidth of 35.7 THz. Within a 100 µs acquisition time window, we obtain rotational state-resolved absorption spectra of formaldehyde, a prototype molecule with high relevance for laser spectroscopy and environmental sciences. To our knowledge, this is the first realization of broadband dual comb spectroscopy in the ultraviolet spectral region and a pioneering tool to allow for real-time monitoring of rovibronic transitions.

中文翻译：

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宽带近紫外双梳光谱

紫外线的高能光子驱动所有分子物种中的电子和振动电子跃迁。因此，如果能够实现宽光谱覆盖、短采集时间和高光谱分辨率（传统应用中相互竞争的要求），那么这种辐射将成为强选择性光谱指纹识别和实时环境监测的主要工具。作为一种在所有三个方面都具有内在效力的方法，我们在这里介绍紫外双梳光谱学，使用两个以 871 THz 为中心的宽带紫外频率梳，覆盖 35.7 THz 的光谱带宽。在 100 µs 采集时间窗口内，我们获得了甲醛的旋转状态分辨吸收光谱，甲醛是一种与激光光谱学和环境科学高度相关的原型分子。据我们所知，这是在紫外光谱区域首次实现宽带双梳光谱，也是实时监测振动电子跃迁的开创性工具。