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Title: Wake dynamics of air filaments generated by high-energy picosecond laser pulses at 1 kHz repetition rate

We investigated the filamentation in air of 7 ps laser pulses of up to 200 mJ energy from a 1.03 μm-wavelength Yb:YAG laser at repetition rates up tof=1kHz. Interferograms of the wake generated show that while pulses in a train of repetition ratef=0.1kHzencounter a nearly unperturbed environment, atf=1kHz, a channel with an axial air density hole of∼<#comment/>20%<#comment/>is generated and maintained at all times by the cumulative effect of preceding laser pulses. Measurements atf=1kHzshow that the energy deposited decreases proportional to the air channel density depletion, becoming more pronounced as the repetition rate and pulse energy increase. Numerical simulations indicate that contrary to filaments generated by shorter duration pulses, the electron avalanche is the dominant energy loss mechanism during filamentation with 7 ps pulses. The results are of interest for the atmospheric propagation of joule-level picosecond pulses from Yb:YAG lasers, of which average powers now surpass 1 kW, and for channeling other directed energy beams.

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Publication Date:
Journal Name:
Optics Letters
Page Range or eLocation-ID:
Article No. 5449
0146-9592; OPLEDP
Optical Society of America
Sponsoring Org:
National Science Foundation
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