Related papers: Avalanche effect and gain saturation in high harmo…
Generation of collimated, quasi-monoenergetic electron beams (peak energy ~17-22MeV, divergence ~10mrad, energy spread ~20%) by interaction of Ti:sapphire laser pulse of 200fs duration, focussed to an intensity of ~ 2.1x10^18 W/cm^2,with an…
We theoretically investigate high-order harmonic generation (HHG) and its ellipticity in gapped graphene, driven by a femtosecond short-pulse laser at various orientation angles, employing the two-band density-matrix equations within the…
High harmonic generation (HHG) is a highly nonlinear emission process in which systems driven by intense laser pulses emit integer multiples (harmonics) of the driving field. This feature is considered universal to all occurrences of HHG.…
We present the operation of the recently introduced Photon Assisted Cascaded Electron Multiplier (PACEM) in xenon at high pressure. The PACEM is a multi step electron multiplier where the VUV scintillation produced in the electron…
Attosecond science promises to reveal the most fundamental electronic dynamics occurring in matter and it can develop further by meeting two linked technological goals related to high-order harmonic sources: higher photon flux (permitting…
We present experimental results showing the appearance of a near-continuum in the high-order harmonic generation (HHG) spectra of atomic and molecular species as the driving laser intensity of an infrared pulse increases. Detailed…
We employ the two-band density-matrix equations and time-dependent density functional theory to calculate high-order harmonic generation (HOHG) in graphene under a femtosecond laser irradiation. Our investigation uncovers a striking…
We present a variational augmentation procedure to optimize the exponents of Gaussian continuum basis sets for simulating strong-field laser ionization phenomena such as higher harmonic generation (HHG) in atoms and ions using the…
High-order harmonic generation (HHG) has become a standard technique for producing attosecond XUV pulses in the laboratory, yet the high flux necessary for nonlinear XUV photoionization remains accessible to only a few research groups.…
We propose an effective scheme for the generation of intense coherent extreme ultraviolet light beams carrying orbital angular momentum (OAM). The light is produced by a high-gain harmonic-generation free-electron laser (FEL), seeded using…
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…
Free-electron lasers (FELs) generate the brightest coherent X-ray pulses available, enabling atomic-resolution and femtosecond-timescale studies across physics, chemistry, and biology. Realising their full potential at extreme peak powers…
Strong-field ionization generally produces ions in a superposition of ionic eigenstates. This superposition is generally not fully coherent und must be described in terms of a density matrix. A recent experiment [E. Goulielmakis et al.,…
Strongly laser-driven semiconductor crystals offer substantial advantages for the study of many-body physics and ultrafast optoelectronics via the high harmonic generation process. While this phenomenon has been employed to investigate the…
Avalanche photodiodes (APDs) are the semiconducting analogue of photomultiplier tubes offering very high internal current gain and fast response. APDs are interesting for a wide range of applications in communications1, laser ranging2,…
We present a study of high-order-harmonic generation (HHG) assisted by extreme ultraviolet (XUV) attosecond pulses, which can lead to the excitation of inner-shell electrons and the generation of a second HHG plateau. With the treatment of…
High-harmonic generation (HHG) in the two topological phases of a finite, one-dimensional, periodic structure is investigated using a self-consistent time-dependent density functional theory (TDDFT) approach. For harmonic photon energies…
Bright betatron x-ray has been generated using an Ar clustering gas jet target irradiated with a 3 TW ultra-high contrast laser. The measured emission flux with photon energy > 2.4 keV reaches 2\times10^8 photons/shot. It is ten-fold…
Absorption induced transparency is an optical phenomenon that occurs in metallic arrays of nanoholes when materials featuring narrow lines in their absorption spectra are deposited on top of it. First reported in the visible range, using…
We studied the high-harmonic generation by the interaction of sub-cycle laser pulses with the He atom. The sub-cycle pulses are modeled using the complex source vector beam model, which is an exact solution to Maxwell's equations and…