Results of theoretical study of the femtosecond Ti:Sa laser pulse propagation in air under the influence of the normal group velocity dispersion are presented. The use of the diffraction-ray tube method for an analysis of numerical solutions of the nonlinear Schrödinger equation in chromatic dispersion medium with the Kerr and plasma nonlinearity makes it possible to determine the main regularities of the femtosecond laser pulse selffocusing and filamentation in air for various pulse durations, initial beam radii, and peak powers. It is shown that under the influence of the group velocity dispersion, the filamentation terminates with an increase in the initial radius of the laser beam even at high values of supercritical powers. With an increase in the dispersion distortions of the pulse, the radius of the energetically replenishing diffraction-ray tube, the angular divergence of the post-filamentation light channel, and the nonlinear focus coordinate normalized to the Rayleigh length increase in the central time slices of the laser pulse and its integral pattern.

中文翻译：

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法向群速度色散作用下飞秒激光脉冲在空气中传播的衍射射线光学

给出了在正常群速度色散影响下飞秒 Ti:Sa 激光脉冲在空气中传播的理论研究结果。使用衍射射线管法对具有克尔和等离子体非线性的色散介质中非线性薛定谔方程的数值解进行分析，可以确定飞秒激光脉冲在空气中自聚焦和成丝的主要规律。脉冲持续时间、初始光束半径和峰值功率。结果表明，在群速度色散的影响下，即使在高超临界功率值下，细丝也会随着激光束初始半径的增加而终止。随着脉冲色散失真的增加，