State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, China.
J Chem Phys. 2019 Feb 28;150(8):084302. doi: 10.1063/1.5083898.
We report high resolution electronic spectroscopy of cold magnesium monofluoride (MgF) molecules in the gas phase, which are created by a combination of laser ablation, chemical reaction, and 6 K helium buffer-gas cooling. Thanks to the sufficient population in the low-lying rotational states, the P, Q, and R branches in the electronic transition of the XΣ to AΠ state are able to be measured unambiguously by in-cell absorption spectra. For the first time, we show that the AΠ state of MgF is actually a normal state, not an inverted one. The laser cooling relevant transitions XΣv=0,1,N=1→AΠ(v=0,J=1/2) are also identified, along with the hyperfine structure of the XΣ(v = 0, N = 1) state. This study provides an important step for ongoing laser cooling experiments of MgF molecules.
我们报告了在气相中冷镁单氟化物 (MgF) 分子的高分辨率电子光谱，这些分子是通过激光烧蚀、化学反应和 6K 氦缓冲气体冷却的组合产生的。由于低能旋转态的充分填充，XΣ 到 AΠ 态的电子跃迁的 P、Q 和 R 支能够通过腔内吸收光谱明确地测量。这是首次表明 MgF 的 AΠ 态实际上是正常态，而不是倒置态。我们还识别了与激光冷却相关的跃迁 XΣv=0,1,N=1→AΠ(v=0,J=1/2)，以及 XΣ(v = 0, N = 1) 态的超精细结构。这项研究为正在进行的 MgF 分子激光冷却实验提供了重要的一步。
