A5001256775- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Orbital Angular Momentum in Optics
- Quantum Information and Cryptography
- Photosynthetic Processes and Mechanisms
- Quantum optics and atomic interactions
- Laser-Plasma Interactions and Diagnostics
- Advanced Chemical Physics Studies
- Carbon Nanotubes in Composites
- Spectroscopy Techniques in Biomedical and Chemical Research
Universidad de Salamanca
2016-2024
Spanish Center for Pulsed Lasers
2016
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...
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...
The photon spectrum in macrocoherent atomic de-excitation via radiative emission of neutrino pairs (RENP) has been proposed as a sensitive probe the mass spectrum, capable competing with conventional experiments. In this paper we revisit intriguing technique order to quantify requirements for statistical determination some properties particular scale and ordering. Our results are sobering. We find that, even under ideal conditions, parameters needs experimental live times days years several...
Recent studies in high-order harmonic generation (HHG) solid targets reveal new scenarios of extraordinary rich electronic dynamics, comparison to the atomic and molecular cases. For later, main aspects process can be described semiclassically terms electrons that recombine when trajectories revisit parent ion. HHG solids has been by an analogous mechanism, this case involving electron-hole pair recombinations. However, it recently reported a substantial part emission corresponds situations...
Isolated attosecond pulse (IAP) generation usually involves the use of short-medium gas cells operated at high pressures. In contrast, long-medium schemes low pressures are commonly perceived as inherently unsuitable for IAP due to nonlinear phenomena that challenge favourable phase-matching conditions. Here we provide clear experimental evidence on isolated extreme-ultraviolet pulses in a semi-infinite cell, demonstrating extended-medium geometries effective production IAPs. To gain deeper...
We study high-order harmonic generation (HHG) in armchair-type single-wall carbon nanotubes (SWNTs) driven by ultrashort, mid-infrared laser pulses. For a SWNT with chiral indices (n, n), we demonstrate that HHG is dominated bands |m| = n - 1 and the cut-off frequency saturates intensity, as it occurs case of single layer graphene. As consequence, SWNTs can be described effectively one-dimensional periodic system, whose high-frequency emission modified through proper control structural...
The efficiency of high-harmonic generation (HHG) from a macroscopic sample is strongly linked to the proper phase matching contributions microscopic emitters. We develop combined micro+macroscopic theoretical model that allows us distinguish relevance high-order harmonic in single-layer graphene. For Gaussian driving beam, our simulations show relevant HHG emission spatially constrained phase-matched ring around beam axis. This remarkable finding direct consequence non-perturbative behavior...
Present mass production of large-area single-layer graphene relies fundamentally on chemical vapor deposition methods. The generation grain boundaries, which divides the sample into a set crystalline domains, is inherent to these fabrication Recent studies have demonstrated strong anisotropy in ultrafast non-linear response when subjected non-perturbative, intense laser fields below damage threshold. We propose exploit this characterize size distribution domains polycrystals via high-order...
Abstract Structured ultrafast laser beams offer unique opportunities to explore the interplay of angular momentum light with matter at femtosecond scale. Linearly polarized vector are paradigmatic examples structured whose topology is characterized by a well-defined Poincaré index. It has been demonstrated that index topological invariant during high-order harmonic generation from isotropic targets, such as noble gases. As result, harmonics produced extreme-ultraviolet same driver. In this...
During the last five years, there has been an increasing interest in generating high-frequency -short wavelength- beams with controllable polarization, due to their potential applications perform ultrafast studies of chiral and/or dichroic systems at nanometer scales. Rather sophisticated configurations have already demonstrated polarization control sub-femtosecond scale through high-order harmonic generation (HHG) atomic gases [1,2]. In parallel, different works recently shown suitability...
Structured laser beams-coherent light beams with nontrivial spatio(temporal) distributions of polarization, phase or intensity-have emerged as unique tools to unravel the electronic dynamics at ultrafast and nanometric scales. A paradigmatic example is high-order harmonic generation (HHG) driven by structured beams, whose deep understanding has triggered emergence a wide variety high-frequency sources topologies that evolve timescales [1]. HHG been mainly studied in atomic molecular gases,...
High-order harmonic generation (HHG) is an ubiquitous tool of great interest in many fields research from imaging to ultrafast spectroscopy [1]. In its most common implementation, intense <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\approx 10^{14}\ \mathrm{W}/\text{cm}^{2})$</tex> infrared (IR) pulse focused on a noble gas target yielding train attosecond pulses the extreme ultraviolet (XUV) spectral region. By adopting proper strategies...
Understanding high-order harmonic generation (HHG) from solid targets holds the key of potential technological innovations in field high-frequency coherent sources. Solids present optical nonlinearities at lower driving intensities, and harmonics can be efficiently emitted due to increased electron density comparison with atomic molecular counterparts. In addition, crystalline solids introduce a new complexity, as symmetries play role anisotropic character response. An extraordinary...
Structured ultrafast laser beams offer unique opportunities to explore the interplay of angular momentum light with matter at femtosecond scale. Linearly polarized vector are paradigmatic examples structured whose topology is characterized by a well-defined Poincar\'e index. It has been demonstrated that index topological invariant during high-order harmonic generation from isotropic targets, such as noble gases. As result, harmonics produced extreme-ultraviolet beams, same driver. We...
We study the macroscopic build-up of high-harmonic signal in single-layer graphene. Our results show that emission is dominated by a phase-matched ring.
We analyse the high harmonic emission from single-layer graphene driven by infrared vector beams. demonstrate that graphene’s anisotropy offers a privileged scenario to explore non-trivial light spin-orbit couplings, which substantially extends possibilities for generation of high-harmonic structured beams currently studied in atomic and molecular targets. In our case, crystal symmetry introduces spin-dependent diffraction pattern that, coupled with fundamental conservation driver’s...
The development of ultrafast laser pulses is enabling unprecedented studies the electronic dynamics Dirac-Weyl materials subjected to intense fields. In particular, generation high-order harmonics in solid systems emerging as a robust process unveil such through harmonic spectroscopy. general case, high-harmonic (HHG) solids performed finite-gap [1] , [2] which electrons are promoted from valence band conduction tunnel excitation, counterpart ionization gases. However, gapless solids—such...
High-order harmonic generation (HHG) has been demonstrated as a successful technique to produce extreme ultraviolet (XUV) coherent light with controlled spin, or polarization, (SAM) and orbital angular momentum (OAM). For gaseous targets, the composition rules follow from independent simultaneous conservation of each type momenta [1] . However, beams can exchange SAM OAM at nanoscale when propagating through inhomogeneous media [2] Although spin-orbit optical interactions are often regarded...