Regularities of femtosecond laser radiation filamentation in air under aberration focusing
D.V. Apeksimov, Yu.E. Geints, A.M. Kabanov, A.V. Petrov, E.E. Khoroshaeva
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: ultrashort laser radiation, structured light, Kerr effect, self-focusing, high-intensity light channels
Abstract
Results of laboratory experiments on control of the filamentation domain of a focused femtosecond laser beam with a spatially structured (using a deformable mirror) wavefront are described. Aberration beams consisting of coherent interleaved ring subapertures obtained with a deformable mirror of specific form are studied. This allows producing inhomogeneities of the distribution of the optical field amplitude during laser beam propagation; these inhomogeneities can subsequently become seeds for light filaments. This approach to control high-power radiation filamentation does not require compensation for distortions of the initial beam profile; on the contrary, it is based on controllable introduction of pre-calculated wavefront aberrations.
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