Effect of input pulse chirp on nonlinear energy deposition and plasma excitation in water

We analyze numerically and experimentally the effect of the input pulse chirp on the nonlinear energy deposition from $5\ \mu$J fs-pulses at $800$ nm to water. Numerical results are also shown for pulses at $400$ nm, where linear losses are minimized, and for different focusing geometries. Input chirp is found to have a big impact on the deposited energy and on the plasma distribution around focus, thus providing a simple and effective mechanism to tune the electron density and energy deposition. We identify three relevant ways in which plasma features may be tuned.Comment: 9 pages, 7 figure

Space and time-resolved study of plasma columns generated by laser filamentation guided electric discharges

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Triggering and Guiding of High-Voltage Tesla Coil Discharges by Femtosecond Laser-Induced Plasma Filaments in Air

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High-voltage Tesla coil discharges triggered and guided by femtosecond laser filaments in air

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A radio-frequency plasma antenna produced by filamentation in air

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Laser guided discharges from a compact Marx generator

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Guiding 1-m scale discharge created by a Tesla generator triggered with femtosecond laser filament in air

International audienceoral presentation We report experiments on laser guided discharges obtained in air by the high voltage delivered by a compact Tesla coil. The home-made Tesla generator provides bursts of voltage oscillations at 100 kHz with peak amplitude of about 350 kV. The voltage is applied between two spherical electrodes. The discharge is triggered by a laser pulse at 800 nm of 350 mJ energy and 700 fs duration. Before reaching the electrodes, the pulse undergoes filamentation, producing thereby a 2 m long continuous plasma column with a diameter of 5 mm and a nearly constant electron density of n ~ 1016 electrons/cm3. No electric discharge is produced by the Tesla generator in the absence of the laser when the interelectrode distance is larger than 32 cm because the electric field is less than the critical value for spontaneous breakdown. Guided discharges activated by filament plasma column are obtained up to an interelectrode distance of 150 cm. The triggering of the guided discharge depends sensitively on the laser arrival time with respect to the phase and amplitude of theTesla voltage cycles. Data on the discharge current, delay between the laser arrival and the initiation of the discharge will be presented. Images of the discharging path guided by the filament will be shown as well

Guiding of meter scale AC discharges by laser filamentation in air

International audienceWe report experiments of laser-guided discharges obtained in air with high voltage bursts delivered by a compact Tesla coil. Characteristics of the guided discharges are studied for electrode gaps ranging from 30 to 170 cm