Sensing equation modification for spatially spaced non-linear foci
V.K. Oshlakov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: atmosphere, aerosol, femtosecond laser, nonlinear focusing, post-filamentation channel, supercontinuum
Abstract
The study of the propagation of high-power ultrashort pulses in the atmosphere is an urgent problem in optics and laser physics. In this paper, we consider the conditions for modifying the basic sensing equation using supercontinuum radiation concentrated in postfilament channels associated with nonlinear foci and filamentation zones of a high-power femtosecond laser pulse. A method for determining the attenuation coefficient is proposed, similar to the well-known logarithmic derivative method used in single-frequency laser sensing. As an example, for a layered homogeneous non-absorbing medium in the single-scattering approximation, the attenuation coefficient is found using radiation at the wavelengths of the supercontinuum concentrated in postfilament channels formed in two spatially spaced nonlinear foci. It is concluded that the modified sensing equation for spatially spaced nonlinear foci is promising for evaluating the effectiveness of broadband optoelectronic communication systems, location detection, and rangefinding.
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