Tóbiás Roland, Furtenbacher Tibor, Simkó Irén, Császár Attila G, Diouf Meissa L, Cozijn Frank M J, Staa Joey M A, Salumbides Edcel J, Ubachs Wim
ELTE Eötvös Loránd University and MTA-ELTE Complex Chemical Systems Research Group, Laboratory of Molecular Structure and Dynamics, Institute of Chemistry, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary.
Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands.
Nat Commun. 2020 Apr 6;11(1):1708. doi: 10.1038/s41467-020-15430-6.
Frequency combs and cavity-enhanced optical techniques have revolutionized molecular spectroscopy: their combination allows recording saturated Doppler-free lines with ultrahigh precision. Network theory, based on the generalized Ritz principle, offers a powerful tool for the intelligent design and validation of such precision-spectroscopy experiments and the subsequent derivation of accurate energy differences. As a proof of concept, 156 carefully-selected near-infrared transitions are detected for HO, a benchmark system of molecular spectroscopy, at kHz accuracy. These measurements, augmented with 28 extremely-accurate literature lines to ensure overall connectivity, allow the precise determination of the lowest ortho-HO energy, now set at 23.794 361 22(25) cm, and 160 energy levels with similarly high accuracy. Based on the limited number of observed transitions, 1219 calibration-quality lines are obtained in a wide wavenumber interval, which can be used to improve spectroscopic databases and applied to frequency metrology, astrophysics, atmospheric sensing, and combustion chemistry.
它们的结合使得能够以超高精度记录饱和无多普勒谱线。基于广义里兹原理的网络理论为这类精密光谱实验的智能设计与验证以及随后精确能量差的推导提供了一个强大工具。作为概念验证，对分子光谱学的一个基准系统HO，以千赫兹精度检测了156条精心挑选的近红外跃迁。这些测量结果，再加上28条极其精确的文献谱线以确保整体连通性，使得能够精确确定最低的正HO能量，目前确定为23.794 361 22(25)厘米⁻¹，以及160个具有同样高精度的能级。基于有限数量的观测跃迁，在很宽的波数区间内获得了1219条校准质量的谱线，这些谱线可用于改进光谱数据库，并应用于频率计量学、天体物理学、大气传感和燃烧化学。
