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arXiv · 1508.01891

Energy deposition from focused terawatt laser pulses in air undergoing multifilamentation

Guillaume Point·Emmanuelle Thouin·André Mysyrowicz·Aurélien Houard
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Abstract

Laser filamentation is responsible for the deposition of a significant part of the laser pulse energy in the propagation medium. We found that using terawatt laser pulses and relatively tight focusing conditions in air, resulting in a bundle of co-propagating multifilaments, more than 60 % of the pulses energy is transferred to the medium, eventually degrading into heat. This results in a strong hydrodynamic reaction of air with the generation of shock waves and associated underdense channels for each short-scale filament. In the focal zone, where filaments are close to each other, these discrete channels eventually merge to form a single cylindrical low-density tube over a $\sim 1 μ\mathrm{s}$ timescale. We measured the maximum lineic deposited energy to be more than 1 J/m.

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Guillaume Point, Emmanuelle Thouin, André Mysyrowicz, Aurélien Houard. 2015-10-13. Energy deposition from focused terawatt laser pulses in air undergoing multifilamentation. https://doi.org/10.1364/oe.24.006271

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