The Kerr self-focusing and group-velocity dispersion (GVD) effects play important roles when a high-power pulsed laser beam propagates from the ground through the nonlinear and dispersive atmosphere to space orbits. For an annular pulsed laser beam, the Kerr self-focusing and GVD effects on the beam quality on the target is studied in this paper. Due to self-focusing, the maximum intensity I _max on the target arrives when the beam power P = P _opt ( P _opt is called the optimal beam power), and the intensity on the target will decrease as the beam power P increases further when P > P _opt . The P _opt of nanosecond and picosecond pulsed beams is lower than that of femtosecond pulsed beams, while the maximum intensity I _max on the target of nanosecond and picosecond pulsed beams is higher than that of femtosecond pulsed beams. The P _opt and I _max of annular pulsed beams are higher than those of Gaussian pulsed beams. In addition, the B integral and the Strehl ratio are also adopted to describe the beam quality on the target. On the other hand, because of the interplay of Kerr self-focusing and GVD effects, the temporal pulse splitting and self-healing may take place on propagation, and the temporal pulse splitting may take place more than once. The results obtained in this paper are useful for laser ablation propulsion's applications in space.

中文翻译：

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通过非线性色散大气传播的环形脉冲激光束的光束质量

当高功率脉冲激光束从地面通过非线性色散大气传播到太空轨道时，克尔自聚焦和群速度色散 (GVD) 效应起着重要作用。对于环形脉冲激光束，本文研究了克尔自聚焦和GVD对目标光束质量的影响。由于自聚焦，最大强度一世 当光束功率到达目标时_最大磷 = 磷 _选择( 磷 _opt称为最佳光束功率），目标上的强度将随着光束功率的增加而降低磷 进一步增加时 磷 > 磷 _选择 。这磷 纳秒和皮秒脉冲光束的_opt低于飞秒脉冲光束，而最大强度一世 纳秒和皮秒脉冲束在目标上的_最大值高于飞秒脉冲束。这磷 _选择和一世 环形脉冲光束的_最大值高于高斯脉冲光束的_最大值。除此之外乙还采用积分和斯特列尔比来描述目标上的光束质量。另一方面，由于克尔自聚焦和GVD效应的相互作用，传播过程中可能会发生时间脉冲分裂和自愈，并且时间脉冲分裂可能发生不止一次。本文获得的结果对于激光烧蚀推进在空间中的应用是有用的。