通过搭建飞秒时间分辨的泵浦探测阴影成像系统，研究了聚焦的飞秒激光脉冲产生空气等离子体的瞬态演化特性，并对不同聚焦条件下空气等离子体的时间特性进行了数值模拟。实验结果表明：聚焦的飞秒激光电离空气等离子体的电子瞬态密度峰值先升高后缓慢下降；同时得到了高时间分辨下的电离速度变化与电子数密度的空间分布。计算结果显示：更高的单脉冲能量对应更高的饱和电子数密度，高数值孔径聚焦条件下隧穿电离也更早出现，表明飞秒时间分辨的泵浦探测阴影成像可为超快激光微加工的瞬态过程提供观测手段，同时可对超快激光微加工过程中的等离子屏蔽效应提供机理解释与加工工艺的优化参考。

ZnGeP₂ (ZGP) crystals have attracted tremendous attention for their applications as frequency conversion devices. Nevertheless, the existence of native point defects, including at the surface and in the bulk, lowers their laser-induced damage threshold by increasing their absorption and forming starting points of the damage, limiting their applications. Here, native point defects in a ZGP crystal are fully studied by the combination of high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and optical measurements. The atomic structures of the native point defects of the Zn vacancy, P vacancy, and Ge-Zn antisite were directly obtained through an HAADF-STEM, and proved by photoluminescence (PL) spectra at 77 K. The carrier dynamics of these defects are further studied by ultrafast pump-probe spectroscopy, and the decay lifetimes of 180.49, 346.73, and 322.82 ps are attributed to the donor V_p⁺ → valence band maximum (VBM) recombination, donor Ge_Zn⁺ → VBM recombination, and donor–acceptor pair recombination of V_p⁺ → V_Zn^-, respectively, which further confirms the assignment of the electron transitions. The diagrams for the energy bands and excited electron dynamics are established based on these ultrahigh spatial and temporal results. Our work is helpful for understanding the interaction mechanism between a ZGP crystal and ultrafast laser, doing good to the ZGP crystal growth and device fabrication.