A5040303145- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Mass Spectrometry Techniques and Applications
- Laser-Plasma Interactions and Diagnostics
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Atomic and Molecular Physics
- Advanced Electron Microscopy Techniques and Applications
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Quantum optics and atomic interactions
- Laser Design and Applications
- Particle Accelerators and Free-Electron Lasers
- Cold Atom Physics and Bose-Einstein Condensates
- Spectroscopy and Laser Applications
- Terahertz technology and applications
- Quantum Information and Cryptography
- Dark Matter and Cosmic Phenomena
- Social and Educational Sciences
- Diamond and Carbon-based Materials Research
- Laser Material Processing Techniques
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Photonic and Optical Devices
- Photoreceptor and optogenetics research
Max-Born-Institute for Nonlinear Optics and Short Pulse Spectroscopy
2019-2025
Lund University
2014-2025
Skåne University Hospital
2022
Stockholm University
2014
AlbaNova
2014
MAX IV Laboratory
2014
Abstract Rabi oscillations are periodic modulations of populations in two-level systems interacting with a time-varying field 1 . They ubiquitous physics applications different areas such as photonics 2 , nano-electronics 3 electron microscopy 4 and quantum information 5 While the theory developed by was intended for fermions gyrating magnetic fields, Autler Townes realized that it could also be used to describe coherent light–matter interactions within rotating-wave approximation 6 Although...
Quantum entanglement between the degrees of freedom encountered in classical world is challenging to observe due surrounding environment. To elucidate this issue, we investigate generated over ultrafast timescales a bipartite quantum system comprising two massive particles: free-moving photoelectron, which expands mesoscopic length scale, and light-dressed atomic ion, represents hybrid state light matter. Although photoelectron spectra are measured classically, allows us reveal information...
Significance In most optics textbooks, one writes the electric field describing an optical wave as a product of temporal and spatial amplitudes. This approximation often breaks down for short pulses. An example such spatiotemporal coupling is chromatic aberrations, where focal properties radiation vary with frequency over pulse bandwidth. this work, we point out significant aberrations attosecond pulses, which depend on geometry generation process. These are intrinsic to process need be...
We present a novel scheme for high-order harmonic generation, enabling the production of spatially separated isolated attosecond pulses. This can be achieved by driving generation process with two identical, but temporally delayed laser pulses, which are noncollinearly overlapping in medium. Our approach provides intense pulses directly from fundamental field, is left undistorted. The method therefore ideally suited pump-probe studies extreme ultraviolet regime and promises new advances...
We measure spectrally and spatially resolved high-order harmonics generated in argon using chirped multi-cycle laser pulses. Using a stable, high-repetition rate we observe detailed interference structures the far-field. The are of two kinds; off-axis from long trajectory only on-axis including short trajectories. former is readily visible far-field spectrum, modulating both spectral spatial profile. To access latter, vary chirp fundamental, imparting different phases on trajectories,...
Cavity-free lasing in atmospheric air has stimulated intense research toward a fundamental understanding of underlying physical mechanisms. In this Letter, we identify new mechanism-a third-harmonic photon mediated resonant energy transfer pathway leading to population inversion argon via an initial three-photon excitation nitrogen molecules irradiated by 261 nm pulses-that enables bidirectional two-color cascaded air. By making pump-probe measurements, conclusively show that such results...
Abstract Multi-pass cells (MPCs) have emerged as very attractive tools for spectral broadening and post-compression applications. We discuss pulse energy limitations of standard MPCs considering basic geometrical scaling principles introduce a novel method using MPC arranged in bow tie geometry. Employing nonlinear propagation simulations, we numerically demonstrate the compression 125 mJ, 1 ps pulses to 50 fs compact 2 m long setup outline routes extend our approach into Joule-regime.
It has been shown by Fano [1] that photoionization of a cesium atom laser pulse tuned to the vicinity Cooper minimum generates spin-polarized electrons. Here we show while rare gases does not provide large spin polarization in minimum, resonances yield much higher overall <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mo stretchy="false">(</a:mo><a:mo>≥</a:mo><a:mn>40</a:mn><a:mo>%</a:mo><a:mo stretchy="false">)</a:mo></a:mrow></a:math>. The increases...
We generate high-order harmonics at high pulse repetition rates using a turnkey laser. High-order 400 kHz are observed when argon is used as target gas. In neon, we achieve generation of photons with energies exceeding 90 eV (∼13 nm) 20 kHz. measure photon flux up to 4.4 × 10(10) per second harmonic in 100 Many experiments employing would benefit from higher rates, and the user-friendly operation opens for applications coherent extreme ultra-violet pulses new research areas.
The authors develop a grid-based implementation of the time-dependent configuration-interaction singles method suitable for computing strong-field ionization small gas-phase molecules. This is then demonstrated in calculations He, LiH, H${}_{2}$O, and C${}_{2}$H${}_{4}$.
Ionisation with ultrashort pulses in the extreme ultraviolet (XUV) regime can be used to prepare an ion a superposition of spin–orbit substates. In this work, we study coherence properties such superposition, created by ionising xenon atoms using two phase-locked XUV at different frequencies. general, if duration driving pulse exceeds quantum beat period, dephasing will occur. If however, frequency difference matches splitting, efficiently increased and does not
Ultrafast processes in matter can be captured and even controlled by using sequences of few-cycle optical pulses, which need to well characterized, both amplitude phase. The same degree control has not yet been achieved for extreme ultraviolet pulses generated high-order harmonic generation gases, with duration the attosecond range. Here, we show that varying spectral phase carrier-envelope (CEP) a high-repetition rate laser, dispersion glass, achieve high relative CEP between consecutive...
We present a specialization of the grid-based implementation time-dependent configuration-interaction singles described in preceding paper (arXiv:2204.09966) to case spherical symmetry. describe intricate time propagator detail, and conclude with few example calculations. Among these, note are high-resolution photoelectron spectra vicinity Fano resonances photoionization neon, spin-polarized photoelectrons from xenon, agreement recent experiments.
Abstract The sub-cycle dynamics of electrons driven by strong laser fields is central to the emerging field attosecond science. We demonstrate how can be probed through high-order harmonic generation, where different trajectories leading same order are initiated at times, thereby probing strengths. find large differences between with respect both their sensitivity driving ellipticity and resonant enhancement. To accurately describe dependence long trajectory harmonics we must include a...
Using only linearly polarized light, we study the possibility of generating spin-polarized photoelectrons from xenon atoms. No net spin polarization is possible, since ground state spinless, but when are measured in coincidence with residual ion, emerges. Furthermore, show that ultrafast dynamics recolliding contribute to an apparent flipping photoelectron, a process has been completely neglected so far all analyses recollision-based processes. We link this phenomenon ``spin-orbit clock''...
When small quantum systems, atoms or molecules, absorb a high-energy photon, electrons are emitted with well-defined energy and highly symmetric angular distribution, ruled by quantization parity conservation. These rules based on approximations symmetries which may break down when exposed to ultrashort intense optical pulses. This raises the question of their universality for simplest case photoelectric effect. Here we investigate photoionization helium sequence attosecond pulses in...
Abstract The development in attosecond physics allows for unprecedented control of atoms and molecules the time domain. Here, ultrashort pulses are used to prepare atomic ions specific magnetic states, which may be important controlling charge migration molecules. Our work fills knowledge gap relativistic hole alignment prepared by femtosecond pulses. research focuses on optimizing central frequency duration exploit spectral features, such as Fano profiles, Cooper minima, giant resonances....
Attosecond pulses in the extreme ultraviolet (XUV) spectral range are today routinely generated via high-order harmonic generation (HHG), when intense ultrashort laser focused into a gaseous medium. The effect is most easily understood semi-classical picture [1]. An electron can tunnel ionize from distorted atomic potential, pick up kinetic energy field, potentially return to its parent ion and recombine. excess emitted as XUV photon. process repeats for every half-cycle of driving resulting...
We study a model for frustrated tunneling ionization using ultrashort laser pulses. The is based on the strong field approximation and it employs saddle point to predict quasiclassical trajectories that are captured Rydberg states. present classification of saddle-point solutions explore their behavior as functions angular momentum final state, well carrier--envelope phase (CEP) pulse. compare state population computed by results obtained numerical propagation time-dependent Schr\"odinger...
The Thomas--Reiche--Kuhn sum rule is used to form an effective potential that added the time-dependent configuration-interaction singles (TDCIS) equations of motion in velocity gauge. purpose include virtual coupling from doubles, which required for size-consistent velocity-gauge TDCIS results. proposed method compared length-gauge results laser-assisted photoionization. Finally, a dynamical interference effect controlled by two-color fields predicted atomic targets.
Cavity-free lasing in atmospheric air has stimulated intense research towards fundamental understanding of underlying physical mechanisms. In this Letter, we identify a new mechanism -- third harmonic photon mediated resonant energy transfer pathway leading to population inversion argon via initial three-photon excitation nitrogen molecules irradiated by 261 nm pulses that enables bidirectional two-color cascaded air. By making pump-probe measurements, conclusively show such results from...
In the last few decades development of ultrafast lasers has revolutionized our ability to gain insight into light-matter interactions. The appearance few-cycle light sources available from visible mid-infrared spectral range and attosecond extreme ultraviolet x-ray technologies provide for first time possibility directly observe control electron dynamics in matter on their natural scale. However, few-fs have hardly been deep (DUV; 4-6 eV, 300-200 nm) are unavailable vacuum (VUV; 6-12 200-100...