Wildi Thibault, Voumard Thibault, Brasch Victor, Yilmaz Gürkan, Herr Tobias
Swiss Center for Electronics and Microtechnology (CSEM), Rue de l'Observatoire 58, 2000, Neuchâtel, Switzerland.
Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607, Hamburg, Germany.
Nat Commun. 2020 Aug 20;11(1):4164. doi: 10.1038/s41467-020-17908-9.
Photo-acoustic spectroscopy (PAS) is one of the most sensitive non-destructive analysis techniques for gases, fluids and solids. It can operate background-free at any wavelength and is applicable to microscopic and even non-transparent samples. Extension of PAS to broadband wavelength coverage is a powerful tool, though challenging to implement without sacrifice of wavelength resolution and acquisition speed. Here we show that dual-frequency comb spectroscopy (DCS) and its potential for unmatched precision, speed and wavelength coverage can be combined with the advantages of photo-acoustic detection. Acoustic wave interferograms are generated in the sample by dual-comb absorption and detected by a microphone. As an example, weak gas absorption features are precisely and rapidly sampled; long-term coherent averaging further increases the sensitivity. This novel approach of dual-frequency comb photo-acoustic spectroscopy (DCPAS) generates unprecedented opportunities for rapid and sensitive multi-species molecular analysis across all wavelengths of light.
光声光谱（PAS）是用于气体、流体和固体的最灵敏的无损分析技术之一。它可以在任何波长下无背景运行，适用于微观甚至不透明的样品。将PAS扩展到宽带波长范围是一个强大的工具，不过在不牺牲波长分辨率和采集速度的情况下实施具有挑战性。在此，我们展示了双频梳状光谱（DCS）及其无与伦比的精度、速度和波长覆盖范围的潜力可以与光声检测的优势相结合。通过双梳状吸收在样品中产生声波干涉图，并由麦克风进行检测。例如，弱气体吸收特征被精确且快速地采样；长期相干平均进一步提高了灵敏度。这种双频梳状光声光谱（DCPAS）的新方法为跨所有光波长的快速灵敏多物种分子分析带来了前所未有的机遇。
