Apeksimov D V, Geints Yu E, Matvienko G G, Oshlakov V K, Zemlyanov A A
Appl Opt. 2022 Feb 20;61(6):1300-1306. doi: 10.1364/AO.447023.
We present the results of our experimental study of the propagation dynamics of high-power femtosecond laser radiation in air with initially imposed amplitude and/or phase modulations. Depending on the modulation type and magnitude, the laser pulse upon nonlinear propagation breaks up into several high-intensity spatially localized light channels, which may or may not contain air plasma and thus are referred to as laser filaments, post-filaments, or plasmaless channels. The pulse modulations are implemented by means of control of the phase or amplitude front using a bimorph deformable mirror or amplitude masks, respectively. We show that the distance of formation and spatial length of high-intensity light channels along a propagation path strongly depend on the shapes and spatial positions of the inhomogeneities created in the transverse phase/amplitude pulse profile, but weakly depend on their sizes.
我们展示了高功率飞秒激光辐射在空气中传播动力学的实验研究结果，该激光辐射初始施加了幅度和/或相位调制。根据调制类型和幅度，激光脉冲在非线性传播时会分裂成几个高强度的空间局域光通道，这些通道可能包含也可能不包含空气等离子体，因此被称为激光细丝、后细丝或无等离子体通道。脉冲调制分别通过使用双压电晶片变形镜控制相位前沿或使用幅度掩模控制幅度前沿来实现。我们表明，沿传播路径的高强度光通道的形成距离和空间长度强烈依赖于在横向相位/幅度脉冲轮廓中创建的不均匀性的形状和空间位置，但对其尺寸的依赖性较弱。
