相关论文: Macroscopic effects in attosecond pulse generation
Plasma high harmonics generation from an extremely intense short-pulse laser is explored by including the effects of ion motion, electron-ion collisions and radiation reaction force in the plasma dynamics. The laser radiation pressure…
In contrast to the case of quasi-monochromatic waves, a focused optical pulse in the few-cycle limit may exhibit two independent curved wavefronts, associated with phase and group retardations, respectively. Focusing optical elements will…
We investigate the self-phase modulation of intense femtosecond laser pulses propagating in an ionizing gas and its effects on collective properties of high-order harmonics generated in the medium. Plasmas produced in the medium are shown…
Intense attosecond magnetic field pulses are predicted to be produced by intense few cycle circularly polarized UV pulses. Numerical solutions of the time dependent Schr\"{o}dinger equation for H$_2^+$ are used to study the dynamical…
We numerically investigate the use of strong THz radiation in assisting single attosecond pulse generation by few-cycle, 800 nm laser pulses. We optimize focusing conditions to generate short and powerful single attosecond pulses of…
Attosecond pulses produced by High-order Harmonic Generation (HHG) in gases driven by intense laser fields have become a cornerstone technique for probing ultrafast electronic motion in matter. These applications require a good knowledge of…
The temporal response of resonances in nanoplasmonic structures typically converts an incoming few-cycle field into a much longer near-field at the spot where non-linear physical phenomena including electron emission, recollision and…
Resonant enhancement of high harmonic generation can be obtained in plasmas containing ions with strong radiative transitions resonant with harmonic orders. The mechanism for this enhancement is still debated. We perform the first temporal…
Ultrafast processes in matter can be captured and even controlled by using sequences of few-cycle optical pulses, which need to be well characterized, both in amplitude and phase. The same degree of control has not yet been achieved for…
The generation of isolated attosecond pulses with high efficiency and high beam quality is essential for attosec- ond spectroscopy. We numerically investigate the supercontinuum generation in a neutral rare-gas medium driven by a two-color…
We report theoretical calculations of high harmonic generation (HHG) by intense infrared lasers in atomic and molecular targets taking into account the macroscopic propagation of both fundamental and harmonic fields. On the examples of Ar…
Attosecond pulses, produced through high-order harmonic generation in gases, have been successfully used for observing ultrafast, sub-femtosecond electron dynamics in atoms, molecules and solid state systems. Today's typical attosecond…
Generation of high intensity attopulses is investigated in cylindrical geometry by using 3D particle-in-cell plasma simulation code. Due to the rotation symmetric target, a circularly polarized laser pulse is considered propagating on the…
We present ab initio calculations using the $R$-matrix with time dependence (RMT) method for high-order harmonic generation (HHG) in argon in a short, intense pulse regime. The calculations employ a $6$-cycle $\sin^2$ pulse at $850$ nm with…
We present a combined theoretical and experimental study of spatio-temporal propagation effects in terahertz (THz) generation in gases using two-color ionizing laser pulses. The observed strong broadening of the THz spectra with increasing…
The dynamics of magnetic fields with amplitude of several tens of Megagauss, generated at both sides of a solid target irradiated with a high intensity (? 1019W/cm2) picosecond laser pulse, has been spatially and temporally resolved using a…
The main effects of an intense THz pulse on gas high harmonic generation are studied via trajectory analysis on the single atom level. Spectral and temporal modifications to the generated radiation are highlighted.
High-order harmonic generation (HHG) in gases has been studied for almost 40 years in many different conditions, varying the laser wavelength, intensity, focusing geometry, target design, gas species, etc. However, no systematic…
The birth of attosecond light sources is expected to inspire a breakthrough in ultrafast optics, which may extend human real-time measurement and control techniques into atomic-scale electronic dynamics. For applications, it is essential to…
Laser-accelerated electron bunches and the secondary radiation sources they produce exhibit unique temporal resolution for probing ultrafast physical processes due to their ultrashort pulse duration. The inherently short temporal profile of…