Termal self-action of high-power continuons pulse-periodic CO2 laser radiation in air. I. Numerical modeling of transfer along the atmospheric path
Yu.E. Geints1, G.N. Grachev2, A.A. Zemlyanov1, A.M. Kabanov1, A.A. Pavlov2, A.G. Ponomarenko2, V.N. Tishchenko2
1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk
Academician Zuev square, Tomsk, 634021, Russia
ygeints@iao.ru
2Institute of Laser Physics of Siberian Branch of the Russian Academy of Science,
13/3, Ac. Lavrentyev's prosp., Novosibirsk, 630090 Russia
tvn25@ngs.ru
Keywords: laser radiation, propagation, absorption, thermal lens, defocusing, modeling
Abstract
A problem of transportation of high-power laser radiation energy at a wavelength of 10.6 μm in the atmosphere is theoretically considered under the conditions of development of its thermal and wind nonlinearities. The power characteristics of continuous and pulse-periodic radiations during propagation along a surface kilometer-long atmospheric path at sharp focusing onto receiver are studied. The main factors having the largest effect on distribution of the influencing radiation are determined. It is established that one succeeds in reducing of undesirable effect of thermal defocusing using a train of low-power short pulses with rather high repetition rate at the expense of the effect of light-induced “blooming” of the gas medium. The questions of scaling of the optical paths from the viewpoint of their equivalence in appearing of thermal nonlinearity are discussed.
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