A5055689940- Laser-Matter Interactions and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Advanced Fiber Laser Technologies
- Molecular spectroscopy and chirality
- Mass Spectrometry Techniques and Applications
- Laser-Plasma Interactions and Diagnostics
- Spectroscopy and Laser Applications
- Solid State Laser Technologies
- Photonic Crystal and Fiber Optics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Molecular Spectroscopy and Structure
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Laser-induced spectroscopy and plasma
- Laser Design and Applications
- Quantum optics and atomic interactions
- Quantum, superfluid, helium dynamics
- Planetary Science and Exploration
- Photoreceptor and optogenetics research
- Advanced X-ray Imaging Techniques
- Atomic and Molecular Physics
- Quantum chaos and dynamical systems
Amplitude Systèmes (France)
2025
Centre Lasers Intenses et Applications
2014-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2024
Centre National de la Recherche Scientifique
2016-2024
Université de Bordeaux
2016-2024
Politecnico di Milano
2017-2022
Bipar
2016
Chiral light-matter interactions have been investigated for two centuries, leading to the discovery of many chiroptical processes used discrimination enantiomers. Whereas most effects result from a response bound electrons, photoionization can produce much stronger chiral signals that manifest as asymmetries in angular distribution photoelectrons along light propagation axis. Here we implement self-referenced attosecond photoelectron interferometry measure temporal profile forward and...
Unravelling the main initial dynamics responsible for chiral recognition is a key stepin understanding of many biological processes. However this challenging task requires sensitive enantiospecic probe to investigate molecular on their natural femtosecond timescale. Here we show that, in gas phase, ultrafast relaxationdynamics photoexcited molecules can be tracked by recording Time-ResolvedPhotoElectron Circular Dichroism (TR-PECD) resulting from photoionisation bya circularly polarized...
We investigate the role of excited states in High-order Harmonic Generation by studying spectral, spatial and temporal characteristics radiation produced near ionization threshold argon few-cycle laser pulses. show that population can lead either to direct XUV emission through Free Induction Decay or generation high-order harmonics from these recombination ground state. By using attosecond lighthouse technique, we demonstrate high-harmonic is temporally delayed a few femtoseconds compared...
Abstract The fast and accurate analysis of chiral chemical mixtures is crucial for many applications but remains challenging. Here we use elliptically-polarized femtosecond laser pulses at high repetition rates to photoionize molecules. 3D photoelectron angular distribution produced provides molecular fingerprints, showing a strong forward-backward asymmetry which depends sensitively on the structure degree ellipticity. Continuously scanning ellipticity analyzing evolution rich,...
Measuring the ultrafast dynamics of chiral molecules in gas phase has been a long standing and challenging quest molecular physics. The main limitation to reach that goal lack highly sensitive chiroptical measurement. By enabling discrimination with up several 10% sensitivity, photoelectron circular dichroism (PECD) offers solution this issue. However, tracking processes requires measuring PECD ultrashort light pulses. Here we compare obtained different sources, from extreme ultraviolet...
Controlling the polarization state of electromagnetic radiation enables investigation fundamental symmetry properties matter through chiroptical processes. Over past decades, many strategies have been developed to reveal structural or dynamical information about chiral molecules with high sensitivity, from microwave extreme ultraviolet range. Most schemes employ circularly elliptically polarized radiation, and more sophisticated configurations involve, for instance, light pulses time-varying...
Strong laser pulses enable probing molecules with their own electrons. The oscillating electric field tears electrons off a molecule, accelerates them, and drives them back toward parent ion within few femtoseconds. are then diffracted by the molecular potential, encoding its structure dynamics angstrom attosecond resolutions. Using elliptically polarized pulses, we show that laser-induced electron diffraction is sensitive to chirality of target. selectively ionizes given orientation along...
We present a spectral phase-only shaping technique allowing to generate arbitrary temporal shapes and demonstrate its use for ultrafast ytterbium-based laser sources. This is based on the introduction of nonlinear chirp that determined solely by input intensity target intensity. describe working principle experimentally generation triangle-shaped pulses at output source, which delivers 150 μ J, sub-200 fs kHz. These are then passed through multipass cell observe wavelength shifting via...
Recent progresses in femtosecond ytterbium-doped fiber laser technology are opening new perspectives strong field physics and attosecond science. High-order harmonic generation from these systems is particularly interesting because it provides high flux beams of ultrashort extreme ultraviolet radiation. A great deal effort has been devoted to optimize the macroscopic parameters. Here we investigate possibility enhancing single-atom response by producing high-order harmonics second, third...
We investigate the photoionization of 16 chiral molecules by elliptical femtosecond pulses in an optical cavity. The photoelectron dichroism is highly sensitive to molecular structure and enables precise measurements enantiomeric excess.
Single photon laser enabled Auger decay (spLEAD) has been redicted theoretically [Phys. Rev. Lett. 111, 083004 (2013)] and here we report its first experimental observation in neon. Using coherent, bichromatic free-electron pulses, have detected the process coherently controlled angular distribution of emitted electrons by varying phase difference between two fields. Since spLEAD is highly sensitive to electron correlation, this a promising method for probing both correlation ultrafast hole...
We present a novel time- and phase-resolved, background-free scheme to study the extreme ultraviolet dipole emission of bound electronic wavepacket, without use any exciting pulse. Using multiphoton transitions, we populate superposition quantum states which coherently emit radiation through free induction decay. This is probed controlled, both in amplitude phase, by time-delayed infrared femtosecond directly measure laser-induced dephasing using simple heterodyne detection based on...
Light-matter interaction based on strong laser fields enables probing the structure and dynamics of atomic molecular systems with unprecedented resolutions, through high-order harmonic spectroscopy, laser-induced electron diffraction, holography. All strong-field processes rely a primary ionization mechanism where electrons tunnel target potential barrier lowered by field. Tunnel is, thus, paramount importance in physics attoscience. However, tunneling properties outgoing electronic wave...
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We present an efficient and robust scheme to produce energetic sub-15 fs pulses centered at 515 nm with a peak power exceeding 3 GW. Combining second-harmonic generation of 135 fs, 50 W Yb-doped fiber amplifier low-loss capillary-based visible pulse compression stage, we reach overall efficiency higher than <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>></mml:mo> </mml:mrow> <mml:mn>20</mml:mn> <mml:mi...
Photoionization of randomly oriented chiral molecules with circularly polarized light leads to a strong forward/backward asymmetry in the photoelectron angular distribution. This chiroptical effect, referred as Photoelectron Circular Dichroism (PECD), was shown take place all ionization regimes, from single photon tunnel ionization. In Resonance Enhanced Multiphoton Ionisation (REMPI) regime, where most table-top PECD experiments have been performed, understanding role intermediate...
We investigate the spatio-spectral properties of extreme ultraviolet (XUV) high harmonic radiation driven by repetition rate femtosecond laser systems. In domain, ring-shaped structures at each order associated with long-trajectory electrons are found to form arrow-shaped cutoff. These observed two different systems: an optical parametric chirped-pulse amplifier system a central wavelength 1.55 μm and 125 kHz rate, temporally compressed ytterbium fiber 1.03 100 rate. As recently pointed out,...
After decades of supremacy the Titanium:Sapphire technology, Ytterbium-based high-order harmonic sources are emerging as an interesting alternative for experiments requiring high flux ultrashort extreme ultraviolet (XUV) radiation. In this article we describe a versatile experimental setup delivering XUV photons in 10-50 eV range. The use cascaded high-harmonic generation enables us to reach 1.8 mW average power at 18 eV. Several spectral focusing schemes presented, select either single or...
Abstract In this work, the photoionization of chiral molecules by an elliptically polarized, high repetition rate, femtosecond laser is probed. The resulting 3D photoelectron angular distribution shows a strong forward–backward asymmetry, which highly dependent not only on molecular structure but also ellipticity pulse. By continuously varying ellipticity, we can observe and enantiomer changes in real time at previously unseen speed precision. technique allows enantiomeric excess pure...
We report on the development of a high-order harmonic generation (HHG)-based ultrafast high-repetition-rate (250 kHz) monochromatic extreme ultraviolet (21.6 eV) source with polarization tunability, specifically designed for multi-modal dichroism in time- and angle-resolved photoemission spectroscopy. Driving HHG using an annular beam allows us to spatially separate high-power 515 nm driving laser from XUV beamlet while preserving linear axis angle tunability. This enables controlling state...
In coherent control schemes, pathways connecting an initial and a final state can be independently controlled by manipulating the complex amplitudes of their transition matrix elements. For paths characterized absorption multiple photons, these quantities depend on magnitude phase between intermediate steps, are expected to strongly affected presence resonances. We investigate photoemission process in neon using phase-controlled two-color extreme ultraviolet pulse with frequency proximity...