Related papers: Two statistical regimes in the transition to filam…

The filamentation instability of counterpropagating symmetric beams of electrons is examined with 1D and 2D particle-in-cell (PIC) simulations, which are oriented orthogonally to the beam velocity vector. The beams are uniform, warm and…

We measure the emission of energetic electrons from the interaction between ultrashort laser pulses and a solid density plasma in the relativistic regime. We detect an electron beam that only appears with few-cycle pulses (< 10 fs) and…

Using numerical simulations, we study propagation of ultrashort light pulses in an inhomogeneously broadened two-level medium. There are two main issues in our study. The first one concerns the transient process of self-induced transparency…

Bandwidth smearing is a chromatic aberration due to the finite frequency bandwidth. In long-baseline optical interferometry terms, it is when the angular extension of the source is greater than the coherence length of the interferogram. As…

The leading amplified spike in backward Raman amplifiers can reach nearly relativistic intensities before the saturation by the relativistic electron nonlinearity, which sets an upper limit to the largest achievable leading spike intensity.…

We describe optimized coherent control methods for two-photon transitions in atoms of a ladder-type three-state energy configuration. Our approach is based on the spatial coherent control scheme which utilizes counter-propagating ultrashort…

The complex internal atomic structure involved in radiative transitions has an effect on the spectrum of fluctuations (noise) of the transmitted light. A degenerate transition has different properties in this respect than a pure two-level…

A new evolution pattern for parametric instabilities in the non-linear stage driven by a broadband laser is studied with kinetic particle-in-cell simulations. It is found that an intermittent excitation of parametric instabilities caused by…

Two dimensional particle-in-cell simulations characterizing the interaction of ultraintense short pulse lasers in the range 10^{18} \leq I \leq 10^{20} W/cm^{2} with converging target geometries are presented. Seeking to examine intensity…

Particle-in-cell (PIC) simulations of collisionless jets of electrons and positrons in an ambient electron-proton plasma have revealed an acceleration of positrons at the expense of electron kinetic energy. The dominant instability within…

Non-linear Compton scattering in ultra-short intense laser pulses is discussed with the focus on angular distributions of the emitted photon energy. This is an observable which is accessible easily experimentally. Asymmetries of the…

We investigate the influence of ultrashort laser filaments on high-voltage discharges and spark-free unloading at various repetition rates and wind conditions. For electric fields well below, close to and above the threshold for discharges,…

We present the results of a 2-D, two fluid (ions and neutrals) simulation of the ambipolar filamentation process, in which a magnetized, weakly ionized plasma is stirred by turbulence in the ambipolar frequency range. The higher turbulent…

We present experimental measurements of the femtosecond time-scale generation of strong magnetic-field fluctuations during the interaction of ultrashort, moderately relativistic laser pulses with solid targets. These fields were probed…

In the frequency power spectral density, periodic oscillations appear as a Dirac comb at integer multiples of the frequency of the period. In weakly nonlinear systems or systems close to the primary instability threshold, the periodicity…

Dual and multi-wavelength lasers, i.e., lasers with the ability to emit at two or more wavelengths in a controlled fashion, represent an exciting new twist in laser physics. Harnessing the mode competition to control them better remains,…

Observations suggest that in normal period radio pulsars, coherent curvature radiation is excited within 10$\%$ of the light cylinder. The coherence is attributed to Langmuir mode instability in a relativistically streaming one-dimensional…

High-power femtosecond laser radiation during the propagation in air (and other transparent media) experiences multiple filamentation. Filamentation is a unique nonlinear optical phenomenon, which is accompanied by a wealth of nonlinear…

The use of strong-field (i.e. intensities in excess of 10^13 Wcm-2) few-cycle ultrafast (durations of 10 femtoseconds or less) laser pulses to create, manipulate and image vibrational wavepackets is investigated. Quasi-classical modelling…

The electric field in laser-driven plasma wakefield acceleration is orders of magnitude higher than conventional radio-frequency cavities, but the energy gain is limited by dephasing between the ultra-relativistic electron bunch and the…