近日，华东师范大学的吴健及其研究团队取得一项新进展。经过不懈努力，他们进行了激光诱导k对齐回波和4π相空间分析。相关研究成果已于2024年9月5日在国际知名学生期刊《物理评论A》上发表。

本文报道了关于N₂O分子在由一对具有不同偏振特性的时滞飞秒激光脉冲诱导产生的对齐回波的实验与理论研究。当施加圆偏振踢动脉冲时，激光传播方向上的对齐回波被激活，从而产生负对齐回波。

在这些情况下，传统的2π相空间分析（其中分子仅限于在垂直于激光传播方向的平面内旋转）无法捕获完整的回波信息。

因此，研究人员考虑了分子在三维空间中的旋转动力学，并采用了一种涉及方位角和极角方向演化的全面相空间分析，即4π相空间分析，以揭示负对齐回波背后的物理机制。

该机制源于方位角和极角相空间中丝状结构的共同贡献。该研究的经典与量子模拟结果与实验观测一致。

附：英文原文

Title: Laser-induced k-alignment echoes and 4π phase-space analysis

Author: Chenxu Lu, Long Xu, Lianrong Zhou, Menghang Shi, Peifen Lu, Kang Lin, Jian Wu

Issue&Volume: 2024/09/05

Abstract: We report on the experimental and theoretical investigation of alignment echoes of N₂O molecules induced by a pair of time-delayed femtosecond laser pulses with different polarizations. When circularly polarized kick pulses are applied, the alignment echoes in the laser propagation direction are activated, giving rise to -alignment echoes. In these cases, the conventional 2π phase-space analysis, where molecules are restricted to rotate in the plane perpendicular to the laser propagation direction, cannot capture the complete echo information. Thus, we consider the rotational dynamics of molecules in the three-dimensional space and adopt a full phase-space analysis involving evolution in both azimuthal and polar directions, termed 4π phase-space analysis, to reveal the underlying physical mechanism of -alignment echoes. Its mechanism results from a joint contribution of the filamentation in both azimuthal and polar phase spaces. Our classical and quantum simulations are consistent with the experimental observations.

DOI: 10.1103/PhysRevA.110.033102

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.033102