A5091203368- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Laser-Plasma Interactions and Diagnostics
- Orbital Angular Momentum in Optics
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Cold Atom Physics and Bose-Einstein Condensates
- Laser Design and Applications
- Terahertz technology and applications
- Quantum optics and atomic interactions
- Nonlinear Photonic Systems
- Quantum Mechanics and Applications
- Crystallography and Radiation Phenomena
- Ion-surface interactions and analysis
- Advanced Electron Microscopy Techniques and Applications
- Quantum Information and Cryptography
- Quantum chaos and dynamical systems
- Quantum, superfluid, helium dynamics
- Spectroscopy and Laser Applications
- Magnetic properties of thin films
- Quantum Chromodynamics and Particle Interactions
- Strong Light-Matter Interactions
Universidad de Salamanca
2015-2024
Bielefeld University
1999-2001
Center for Theoretical Physics
2000
Polish Academy of Sciences
2000
Universitat Autònoma de Barcelona
1991-1996
Universitat Pompeu Fabra
1993
High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding a mid-infrared femtosecond in high-pressure gas, ultrahigh harmonics can be generated, up orders greater than 5000, emerge as bright supercontinuum spans entire electromagnetic spectrum more 1.6 kilo-electron volts, allowing, principle, of pulses short 2.5...
Pulses with a twist and torque Structured light beams can serve as vortex carrying optical angular momentum have been used to enhance communications imaging. Rego et al. generated dynamic pulses by interfering two incident time-delayed different orbital momenta through the process of high harmonic generation. A controlled time delay between allowed extreme-ultraviolet beam exhibit time-dependent momentum, called self-torque. Such could potentially be manipulate nanostructures atoms on...
We present a theoretical study of high-order harmonic generation (HHG) and propagation driven by an infrared field carrying orbital angular momentum (OAM). Our calculations unveil the following relevant phenomena: extreme-ultraviolet vortices are generated survive to effects, transport high-OAM multiples corresponding OAM driving and, finally, different emitted with similar divergence. also show possibility combining HHG phase locking produce attosecond pulses helical pulse structure.
High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light much shorter wavelengths. Optimizing the conversion into soft x-rays typically demands trade-off between two competing factors. Because reduced quantum diffusion radiating electron wave function, emission from each species highest when short-wavelength ultraviolet driving used. However, phase matching--the constructive addition x-ray waves large number atoms--favors...
Light beams carrying orbital angular momentum, such as Laguerre-Gaussian beams, give rise to the violation of standard dipolar selection rules during interaction with matter yielding, in general, an exchange momentum larger than hbar per absorbed photon. By means ab initio 3D numerical simulations, we investigate detail a hydrogen atom intense Gaussian and light pulses. We analyze dependence polarization, carrier-envelope phase light, well relative position between vortex. In addition,...
We demonstrate theoretically that the temporal structure of high harmonic x-ray pulses generated with midinfrared lasers differs substantially from those near-infrared pulses, especially at photon energies. In particular, we show that, although total width bursts spans femtosecond time scales, pulse exhibits a zeptosecond due to interference emission multiple reencounters electron wave packet ion. Properly filtered and without any compensation chirp, regular subattosecond keV waveforms can...
High-order harmonic generation (HHG) has been recently proven to produce extreme-ultraviolet (XUV) vortices from the nonlinear conversion of infrared twisted beams. Previous works have demonstrated a linear scaling law vortex charge with order. We demonstrate that this simple hides an unexpectedly rich scenario for buildup orbital angular momentum (OAM) due nonperturbative behavior HHG. The complexity these XUV beams appears only when HHG is driven by nonpure modes, where OAM content...
High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, date shortest attosecond (as) pulses have been produced only extreme ultraviolet (EUV) region of spectrum below 100 eV, which limits range materials molecular systems that can be explored. Here we use advanced experiment theory demonstrate a remarkable convergence physics: when mid-infrared are used drive high process, conditions for optimal bright soft...
Circularly polarized attosecond pulse trains in the EUV region were reconstructed using 3D metrology.
Intense laser ionization expands Einstein's photoelectric effect rules giving a wealth of phenomena widely studied over the last decades. In all cases, so far, photons were assumed to carry one unit angular momentum. However it is now clear that can possess extra momentum, orbital momentum (OAM), related their spatial profile. We show complete description photoionization by OAM photons, including new selection involving more than explore theoretically interaction single electron atom located...
We present an efficient approach for computing high-order harmonic propagation based on the discrete dipole approximation. In contrast with other approaches, our strategy is total field as superposition of driving radiated by elemental emitters sample. this way we avoid numerical integration wave equation, Maxwell's equations have analytical solution elementary (pointlike) emitter. The valid low-pressure gases interacting strong fields near saturation threshold (i.e., partially ionized),...
High-order harmonic generation (HHG) driven by beams carrying orbital angular momentum has been recently demonstrated as a unique process to generate spatio-temporal coherent extreme ultraviolet (XUV)/x-ray radiation with attosecond helical structure. We explore the details of mapping driving vortex its spectrum. In particular we show that geometry vortices is complex, arising from superposition contribution short and long quantum paths responsible HHG. Transversal phase-matching path...
Structured light in the short-wavelength regime opens exciting avenues for study of ultrafast spin and electronic dynamics. Here, we demonstrate theoretically experimentally generation vector-vortex beams (VVB) extreme ultraviolet through high-order harmonic (HHG). The up-conversion VVB, which are spatially tailored their orbital angular momentum, is ruled by conservation topological Pancharatnam charge HHG. Despite complex propagation driving beam, high-harmonic VVB robustly generated with...
The extreme nonlinear optical process of high-harmonic generation (HHG) makes it possible to map the properties a laser beam onto radiating electron wave function and, in turn, emitted x-ray light. Bright HHG beams typically emerge from longitudinal phased distribution atomic-scale quantum antennae. Here, we form transverse necklace-shaped array linearly polarized emitters, where orbital angular momentum conservation allows us tune line spacing and divergence ultraviolet soft combs. on-axis...
Abstract Linearly polarized vector beams are structured lasers whose topology is characterized by a well-defined Poincaré index, which topological invariant during high-order harmonic generation. As such, harmonics produced as extreme-ultraviolet that inherit the of driver. This holds for isotropic targets such noble gases, but analogous behaviour in crystalline solids still open to discussion. Here, we demonstrate this conservation rule breaks solids, virtue their anisotropic non-linear...
We present ab initio computations of the ionization two-electron atoms by short pulses intense linearly polarized Ti:sapphire laser radiation beyond one-dimensional approximation. In model electron correlation is included in its full dimensionality, while center-of-mass motion restricted along polarization axis. Our results exhibit a rich double quantum dynamics direction transversal to field polarization, which neglected previous models based on
The physics of laser-mater interactions beyond the perturbative limit configures field extreme non-linear optics. Although most experiments have been done in near infrared ( lambda <or= 1 microm), situation is changing nowadays with development sources at longer wavelengths (<5 opening new perspectives synthesis shorter XUV attosecond pulses and higher frequencies. theory intense-field based either on exact numerical integration time-dependent Schrödinger equation or models, mostly...
Vortex light beams are structures of the electromagnetic field with a spiral phase ramp around point-phase singularity. These vortices have many applications in optical regime, ranging from trapping and quantum information to spectroscopy microscopy. The extension into extreme-ultraviolet (XUV)/X-ray regime constitutes significant step forward bring those nanometer or even atomic scale. recent development new generation X-ray sources, refinement other techniques, such as harmonic generation,...
High-order harmonic generation stands as a unique nonlinear optical up-conversion process, mediated by laser-driven electron recollision mechanism, which has been shown to conserve energy, momentum, and spin orbital angular momentum. Here we present theoretical simulations demonstrate that this process also conserves mixture of the latter, torus-knot momentum $J_\gamma$, producing high-order harmonics with driving pulses are invariant under coordinated rotations. We charge $J_\gamma$ emitted...
High harmonic generation in atomic or molecular targets stands as a robust mechanism to produce coherent ultrashort pulses with controllable polarization the extreme-ultraviolet. However, production of elliptically circularly-polarized harmonics is not straightforward, demanding complex combinations drivers, use alignment techniques. Nevertheless, recent studies show feasibility high-harmonic solids. In contrast atoms and molecules, solids are high-density therefore more efficient radiation...
Recent developments of high harmonic generation (HHG) have enabled the production structured extreme-ultraviolet (EUV) ultrafast laser beams with orbital angular momentum (OAM). Precise manipulation and characterization their spatial structure are paramount for application in state-of-the-art studies. In this work, we report EUV vortex bearing a topological charge as 100. Thanks to OAM conservation, HHG noble gases offers unique opportunity generate from low infrared beams. A high-resolution...
The landscape of ultrafast structured light pulses has significantly advanced thanks to the ability high-order harmonic generation (HHG) translate spatial properties infrared laser beams extreme-ultraviolet (EUV) spectral range. In particular, up-conversion orbital angular momentum (OAM) enabled harmonics whose OAM scales linearly with order and topological charge driving field. Having a well-defined OAM, each is emitted as an EUV femtosecond vortex pulse. However, order-dependent across...