AI 中文总结
本研究利用反应显微镜结合逐事件时间重建技术，探究全光阱中激光冷却锂原子的低强度多色光电离，识别5p、5f态共振激发及额外电离通道，揭示光电离产额的偏振依赖机制。
AI 中文摘要
由囚禁激光与辅助激光场诱导的光电离是许多激光冷却和光阱实验的固有特征，但其微观动力学很少被直接研究。本研究采用反应显微镜，结合逐事件光电离时间检索技术，将动量分辨光电子能谱拓展至连续波激光-原子相互作用领域。我们研究了全光阱中束缚的激光冷却锂原子的低强度多色光电离过程，针对不同激光波长与偏振构型记录了完整的三维电子动量分布与动能谱，识别出5p与5f态的共振激发，并揭示了5f态自发衰变至4d态后产生的额外电离通道。光电离产额的显著偏振依赖性可通过磁子能级选择定则及不同虚激发路径的相干干涉加以解释。这些结果表明，反应显微镜结合逐事件时间重建技术，为研究激光冷却原子系统中的微观电子动力学提供了有力手段，并为光阱过程中发生的光电离过程提供了新的见解。
英文摘要
Photoionization induced by trapping and auxiliary laser fields is an inherent feature of many laser-cooling and optical trapping experiments, yet its microscopic dynamics are rarely investigated directly. In this work, we employ a reaction microscope implementing an event-by-event photoionization time retrieval technique to extend momentum-resolved photoelectron spectroscopy to continuous-wave laser--atom interactions. We investigate low-intensity multicolor photoionization of laser-cooled lithium atoms confined in an all-optical trap. Complete three-dimensional electron momentum distributions and kinetic-energy spectra recorded for different laser wavelengths and polarization configurations identify resonant excitation of the $5p$ and $5f$ states and reveal an additional ionization channel following spontaneous decay from the $5f$ to the $4d$ state. A pronounced polarization dependence of the photoionization yield is explained by magnetic-sublevel selection rules and the coherent interference of different virtual excitation pathways. These results demonstrate that reaction microscopy combined with event-by-event time reconstruction provides a powerful approach for investigating microscopic electronic dynamics in laser-cooled atomic systems and offers new insight into photoionization processes occurring during optical trapping.
