Publications by authors named "Nikolay A Panov"

High-intensity (∼1 TW/cm2 and higher) region formed in the propagation of ∼60 GW, 90 fs Ti:Sapphire laser pulse on a ∼100 m path in air spans for several tens of meters and includes a plasma filament and a postfilament light channel. The intensity in this extended region is high enough to generate an infrared supercontinuum wing and to initiate laser-induced discharge in the gap between the electrodes. In the experiment and simulations, we delay the high-intensity region along the propagation direction by inserting metal-wire meshes with square cells at the laser system output.

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By rotating the four-section π-shifted phase plate in the transverse plane relatively to the axes of the elliptical beam of 800-nm, 1.1-mJ, 35-fs pulse propagating in air, we switch between the regime of four parallel plasma channels and the regime of spatial symmetry breakup followed by on-axis plasma channel formation identified on the burnt paper images of the beam. Relaxation of the π-phase shift for 45 phase plate rotation is demonstrated explicitly in 3D+time carrier wave resolved numerical simulations yielding the initial step-like phase distribution degradation along the plasma region.

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We developed a model of femtosecond filamentation which includes high-order Kerr effect and an arbitrary polarization of a laser pulse. We show that a circularly polarized pulse has maximum filament intensity. Also, we show that, independently of the initial pulse polarization, the value of a maximum filament intensity tends to the maximum intensity of either linearly or circularly polarized pulse.

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