Energy deposition from focused terawatt laser pulses in air undergoing multifilamentation

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 $\sim 1\mu \mathrm{s}$ timescale. We measured the maximum lineic deposited energy to be more than 1 J/m.

7 pages, 7 figures

References in corpus (5)

• Superfilamentation in air
• Generation of long-lived underdense channels using femtosecond filamentation in air
• Direct measurement of the acoustic waves generated by femtosecond filaments in air
• Sensitivity of propagation and energy deposition in femtosecond filamentation to the nonlinear refractive index
• Two-color interferometer for the study of laser filamentation triggered electric discharges in air

Cited by in corpus (4)

• Filamentation of Mid-IR pulses in ambient air in the vicinity of molecular resonances
• Optimal laser pulse energy partitioning for air ionization
• Plasma dynamics of a laser filamentation-guided spark
• Maximizing energy deposition by shaping few-cycle laser pulses