The effect of turbulence on generation of intense light channels during propagation of femtosecond laser pulses along 100-meter air path
D.V. Apeksimov, P.A. Babushkin, A.A. Zemlyanov, A.M. Kabanov, D.I. Kochetov, V.K. Oshlakov, 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 pulse, high-intensity light channels, turbulence, multiple filamentation
Abstract
Remote control of intense laser beams is an important problem of atmospheric optics. It is of special interest for atmospheric sounding, where turbulence can affect beam propagation. We experimentally study the effect of a turbulent layer produced at the beginning of a laser radiation propagation path on the characteristics of the filamentation domain and generation of high-intensity plasmaless channels for laser beams 2.5 and 5 cm diameter, including under the phase control of the transverse beam structure with a deformable mirror. Turbulence leads to the approach of the beginning of multifilamentation domain to the radiation source, which is, however, insignificant (< 10% of the path length). More important that a turbulent layer formed at the beginning of the path results in a multiple increase in the number of intense (mean intensity is ~ 1011 - 1012 W/cm2) light channels in a laser beam during its nonlinear propagation, which induce two-photon fluorescence of dyes at a distance of longer than 100 m from the radiation source with the signal level sufficient for its recording by the lidar scheme. Hence, this laser beam structure can be used for sounding natural and anthropogenic aerosols.
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