A5011624193- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Advanced X-ray Imaging Techniques
- Laser-Plasma Interactions and Diagnostics
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Advanced Electron Microscopy Techniques and Applications
- Advanced Chemical Physics Studies
- Solid State Laser Technologies
- Laser-induced spectroscopy and plasma
- Orbital Angular Momentum in Optics
- Advanced Condensed Matter Physics
- Irish and British Studies
- Photosynthetic Processes and Mechanisms
- Magnetic and transport properties of perovskites and related materials
- Photonic Crystal and Fiber Optics
- Photochemistry and Electron Transfer Studies
- Enzyme Structure and Function
- Physics of Superconductivity and Magnetism
- X-ray Spectroscopy and Fluorescence Analysis
- High-pressure geophysics and materials
- Ion-surface interactions and analysis
- Photonic and Optical Devices
- Magnetism in coordination complexes
- Atomic and Molecular Physics
SLAC National Accelerator Laboratory
2015-2024
National University of Ireland, Maynooth
2019-2024
Linac Coherent Light Source
2013-2023
Fermi National Accelerator Laboratory
2013-2021
Stanford University
2017-2021
Menlo School
2016-2019
Lawrence Livermore National Laboratory
2019
Infrared Laboratories (United States)
2019
Friedrich Schiller University Jena
2019
Czech Technical University in Prague
2019
We demonstrate a technique that uses high-order harmonic generation in molecules to probe nuclear dynamics and structural rearrangement on subfemtosecond time scale. The chirped nature of the electron wavepacket produced by laser ionization strong field gives rise similar chirp photons emitted upon electron-ion recombination. Use this light allows information about be gained with 100-attosecond temporal resolution, from excitation an 8-femtosecond pulse, single shot. Measurements molecular...
Structural rearrangements within single molecules occur on ultrafast time scales. Many aspects of molecular dynamics, such as the energy flow through excited states, have been studied using spectroscopic techniques, yet goal to watch evolve their geometrical structure in real remains challenging. By mapping nuclear motions femtosecond x-ray pulses, we created real-space representations evolving dynamics during a well-known chemical reaction and show series time-sorted structural snapshots...
Absorption of light in hybrid perovskite solar cells leads to ultrafast large-amplitude deformations the inorganic sublattice.
We present the perfect waveform which, during a strong field interaction, generates maximum possible electron recollision energy for any given oscillation period, over 3 times as high that pure sinusoidal wave. This ideal has form of linear ramp with dc offset. A genetic algorithm was employed to find an optimized practically achievable composed longer wavelength field, provide offset, in addition higher frequency components. second is found be capable generating energies those while...
The effects of electronic structure and symmetry are observed in laser driven high-order harmonic generation for aligned conjugated polyatomic molecular systems. dependence the yield on angle between axis polarization driving field is seen to contain fingerprint highest occupied orbitals acetylene allene, a good quantitative agreement with calculations employing strong approximation was found. These measurements support extension recently proposed orbital imaging techniques beyond simple...
Observing the motion of nuclear wavepackets during a molecular reaction, in both space and time, is crucial for understanding controlling outcome photoinduced chemical reactions. We have imaged vibrational wavepacket isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured precision 0.07 {\AA} temporal resolution 230 fs full-width at half-maximum (FWHM). method not only sensitive to position but also shape...
Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with temporal and spatial resolution 30 fs 0.3 Å. This high fidelity is due interference between the nonstationary excitation stationary initial charge distribution. The state as local oscillator for heterodyne amplification excited distribution retrieve real-space movies atomic on ångstrom scales. has not been employed image internal in molecules...
Optical and X-ray free-electron laser measurements reveal ligand substitution in an Fe(<sc>ii</sc>)-centered complex extends its MLCT lifetime.
Abstract Imaging changes in molecular geometries on their natural femtosecond timescale with sub-Angström spatial precision is one of the critical challenges chemical sciences, as nuclear geometry determine reactivity. For photoexcited molecules, dynamics photoenergy conversion path and efficiency. Here we report a gas-phase electron diffraction experiment using megaelectronvolt (MeV) electrons, where captured rotational wavepacket nonadiabatically laser-aligned nitrogen molecules. We...
Abstract Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties molecules, nanomaterials or correlated solids, and enable advanced applications in imaging metrology. Extending to high repetition rates portends great experimental benefits, yet efficient conversion correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source femtosecond at 50-kHz rate, utilizing...
We report a new dynamic two-center interference effect in high-harmonic generation from ${\mathrm{H}}_{2}$, which the attosecond nuclear motion of ${\mathrm{H}}_{2}^{+}$ initiated at ionization causes to be observed lower harmonic orders than would case for static nuclei. To enable this measurement we utilize recently developed technique probing dynamics small molecules. The experimental results are reproduced by theoretical analysis based upon strong-field approximation incorporates...
High harmonic generation (HHG) of intense infrared laser radiation (Ferray et al., J. Phys. B: At. Mol. Opt. 21:L31, 1988; McPherson Soc. Am. B 4:595, 1987) enables coherent vacuum-UV (VUV) to soft-X-ray sources. In the usual setup, energetic femtosecond pulses are strongly focused into a gas jet, restricting interaction length Rayleigh range focus. The average photon flux is limited by low conversion efficiency and power complex amplifier systems (Keller, Nature 424:831, 2003; Südmeyer Nat....
Understanding interfacial charge-transfer processes on the atomic level is crucial to support rational design of energy-challenge relevant systems such as solar cells, batteries, and photocatalysts. A femtosecond time-resolved core-level photoelectron spectroscopy study performed that probes electronic structure interface between ruthenium-based N3 dye molecules ZnO nanocrystals within first picosecond after photoexcitation from unique perspective Ru reporter atom at center dye. transient...
We describe a complete technological system at Imperial College London for Attosecond Science studies. The comprises few-cycle, carrier envelope phase stabilized laser source which delivers sub 4 fs pulses to vibration-isolated attosecond vacuum beamline. beamline is used the generation of isolated in extreme ultraviolet (XUV) kilohertz repetition rates through laser-driven high harmonic gas targets. incorporates: interferometers producing pulse sequences pump-probe studies; facility...
Dynamics of a ground-state chemical reaction are revealed by ultrafast x-ray scattering.