A comprehensive theoretical treatment of laser-assisted electron-atom radiative recombination in the presence of short laser pulses is presented. Our formulation lacks various unphysical effects observed in previous works, such as oscillations and high-energy tails in the spectrum of emitted radiation; however, it accounts for a contribution from the field-free process. As a result, the energy distribution of emitted radiation consists of a point spectrum embedded in a continuum. We demonstrate that the features of the latter are determined by the laser field. For instance, in the case of a train of pulses, comb structures appear in the radiation spectrum. We attribute them to constructive interference between probability amplitudes of recombination assisted by each pulse from the train. Finally, we show that the vector potential describing the laser field is encoded in the spectrogram of emitted radiation. This suggests the use of the spectrogram for a complete temporal reconstruction of the laser field, irrespective of whether it is an isolated pulse or a pulse train.

中文翻译：

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短激光脉冲中的激光辅助电子原子辐射复合

提出了在存在短激光脉冲的情况下激光辅助电子原子辐射复合的综合理论处理。我们的公式缺乏以前工作中观察到的各种非物理效应，例如发射辐射光谱中的振荡和高能尾；然而，它说明了无场过程的贡献。因此，发射辐射的能量分布由嵌入连续谱中的点光谱组成。我们证明后者的特征是由激光场决定的。例如，在脉冲串的情况下，梳状结构出现在辐射光谱中。我们将它们归因于由来自列车的每个脉冲辅助的重组概率幅度之间的建设性干扰。最后，我们展示了描述激光场的矢量势在发射辐射的光谱图中编码。这表明使用频谱图对激光场进行完整的时间重建，而不管它是孤立脉冲还是脉冲序列。