Abstract

The fluorescence dynamics of optically dense but dilute atomic ensembles cooled to sub-Doppler temperatures and excited by resonant pulsed radiation is studied. Apart from total radiation intensity, the temporal variations of the spectral composition of fluorescence and its polarization, as well as the variation of the spatial distribution of excitation in the atomic ensemble, are analyzed. Based on this analysis, it is shown that the role of radiation trapping becomes smaller with time, and subradiance quantum states formed as a result of the resonant dipole–dipole interatomic interaction become the main factor determining the slow atomic excitation decay. The dependence of the subradiance form on the ensemble size is analyzed.

中文翻译：

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共振脉冲辐射激发的冷原子和稀释原子集合的亚辐射

摘要

研究了光学致密但稀薄的原子团簇的荧光动力学，该原子团簇冷却至亚多普勒温度并被共振脉冲辐射激发。除了总辐射强度，还分析了荧光光谱成分及其偏振态的时间变化，以及原子团中激发空间分布的变化。基于此分析，结果表明，辐射俘获的作用随时间而变小，并且由于共振偶极-偶极原子间相互作用而形成的亚辐射量子态成为决定慢原子激发衰变的主要因素。分析了亚辐射形式对集合大小的依赖性。