A5048833601- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Fiber Laser Technologies
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Advanced Electron Microscopy Techniques and Applications
- Photocathodes and Microchannel Plates
- Advanced X-ray Imaging Techniques
- Quantum, superfluid, helium dynamics
- Laser Design and Applications
- Atomic and Molecular Physics
- Photonic Crystals and Applications
- Photonic Crystal and Fiber Optics
- Electron and X-Ray Spectroscopy Techniques
- Solid State Laser Technologies
- Advanced Fluorescence Microscopy Techniques
- Laser-induced spectroscopy and plasma
- Spectroscopy and Laser Applications
- Photonic and Optical Devices
Lund University
2020-2024
Advancements in light engineering have led to the creation of pulsed laser sources capable delivering high-repetition-rate, high-power few-cycle pulses across a wide spectral range, enabling exploration many fascinating nonlinear processes occurring all states matter. High-harmonic generation, one such process, which converts low-frequency photons driver field into soft x-rays, has revolutionized atomic, molecular, and optical physics, leading progress attosecond science ultrafast...
Abstract Attosecond pulses, produced through high-order harmonic generation in gases, have been successfully used for observing ultrafast, subfemtosecond electron dynamics atoms, molecules and solid state systems. Today’s typical attosecond sources, however, are often impaired by their low repetition rate the resulting insufficient statistics, especially when number of detectable events per shot is limited. This case experiments, where several reaction products must be detected coincidence,...
Abstract The photoionization of xenon atoms in the 70–100 eV range reveals several fascinating physical phenomena such as a giant resonance induced by dynamic rearrangement electron cloud after photon absorption, an anomalous branching ratio between intermediate Xe + states separated spin-orbit interaction and multiple Auger decay processes. These have been studied past, using particular synchrotron radiation, but without access to real-time dynamics. Here, we study dynamics 4 d on its...
We propose a continuous variable quantum state tomography protocol of electrons which result from the ionization atoms or molecules by absorption extreme ultraviolet light pulses. Our is benchmarked against direct calculation photoelectrons ejected helium and argon in vicinity Fano resonance. In latter case, we furthermore distill ion-photoelectron entanglement due to spin-orbit splitting. This opens new routes towards investigation coherence properties on ultrafast timescale.
The implementation of attosecond photoelectron-photoion coincidence spectroscopy for the investigation atomic and molecular dynamics calls a high-repetition-rate driving source combined with experimental setups characterized by excellent stability data acquisition over time intervals ranging from few hours up to days. This requirement is crucial processes low cross sections characterization fully differential photoelectron(s) photoion(s) angular energy distributions. We demonstrate that...
We study resonant two-photon ionization of helium atoms via the 1 s 3 p , 4 and 5 P states using 15 th harmonic a titanium-sapphire laser for excitation weak fraction field ionization. The phase photoelectron wavepackets is measured by an attosecond interferometric technique, 17 harmonic. perform experiments with angular resolution velocity map imaging spectrometer high energy magnetic bottle electron spectrometer. Our results are compared to calculations random approximation exchange...
High-order harmonic generation (HHG) provides scalable sources of coherent extreme ultraviolet radiation with pulse duration down to the attosecond time scale. Efficient HHG requires constructive interplay between microscopic and macroscopic effects in volume, which can be achieved over a large range experimental parameters from driving field properties those generating medium. Here, we present systematic study yield as function gas pressure medium length. Two regimes for optimum are...
Attosecond photoelectron spectroscopy has opened up for studying light–matter interaction on ultrafast time scales. It is often performed with interferometric experimental setups that require outstanding stability. We demonstrate and characterize in detail an actively stabilized, versatile, high spectral resolution attosecond beamline based a Mach-Zehnder interferometer. The active stabilization keeps the interferometer ultra-stable several hours RMS stability of 13 as total pump-probe delay...
Fano resonances are ubiquitous phenomena appearing in many fields of physics, e.g. atomic or molecular photoionization, electron transport quantum dots. Recently, attosecond interferometric techniques have been used to measure the amplitude and phase photoelectron wavepackets close argon helium, allowing for retrieval temporal dynamics photoionization process. In this work, we study atoms $3s^13p^64p$ autoionizing state using an technique with high spectral resolution. The shows a monotonic...
Fano resonances are ubiquitous phenomena appearing in many fields of physics, e.g., atomic or molecular photoionization, electron transport quantum dots. Recently, attosecond interferometric techniques have been used to measure the amplitude and phase photoelectron wave packets close argon helium, allowing for retrieval temporal dynamics photoionization process. In this work, we study atoms <a:math...
We present a simple method for choosing an efficient high-order harmonic generation (HHG) gas target, given the driving laser characteristics. The predictions are validated by simulations based on solving time-dependent Schrödinger and propagation equations.
Attosecond photoelectron spectroscopy is often performed with interferometric experimental setups that require outstanding stability. We demonstrate and characterize in detail an actively stabilized, versatile, high spectral resolution attosecond beamline. The active-stabilization system can remain ultra-stable for several hours RMS stability of 13 as a total pump-probe delay scanning range \sim 400 fs. A tunable femtosecond laser source to drive high-order harmonic generation allows...
We demonstrate, using analytic models, simulations and experiments, that efficient generation of high-order harmonics is possible across a large range parameters, if the density medium length follow hyperbolic equation.
A photoelectron, emitted due to the absorption of light quanta as described by photoelectric effect, is often characterized experimentally a classical quantity, its momentum. However, since photoelectron quantum object, rigorous characterization requires reconstruction complete state, photoelectron's density matrix. Here, we use state tomography fully characterize photoelectrons from helium and argon atoms upon ultrashort, extreme ultraviolet pulses. While in measure pure photoelectronic...
Attosecond pulses, produced through high-order harmonic generation in gases, have been successfully used for observing ultrafast, sub-femtosecond electron dynamics atoms, molecules and solid state systems. Today's typical attosecond sources, however, are often impaired by their low repetition rate the resulting insufficient statistics, especially when number of detectable events per shot is limited. This case experiments where several reaction products must be detected coincidence, surface...
We propose a continuous variable quantum state tomography protocol of electrons which result from the ionization atoms or molecules by absorption extreme ultraviolet light pulses. Our is benchmarked against direct calculation photoelectrons ejected helium and argon in vicinity Fano resonance. In latter case, we furthermore distill ion-photoelectron entanglement due to spin-orbit splitting. This opens new routes towards investigation coherence properties on ultrafast timescale.
We study resonant two-photon ionization of helium atoms via the $1s3p$, $1s4p$ and $1s5p^1$P$_1$ states using 15$^\mathrm{th}$ harmonic a titanium-sapphire laser for excitation weak fraction field ionization. The phase photoelectron wavepackets is measured by an attosecond interferometric technique, 17$^\mathrm{th}$ harmonic. perform experiments with angular resolution velocity map imaging spectrometer high energy magnetic bottle electron spectrometer. Our results are compared to...
The implementation of attosecond photoelectron-photoion coincidence spectroscopy for the investigation atomic and molecular dynamics calls a high-repetition-rate driving source combined with experimental setups characterized by excellent stability data acquisition over time intervals ranging from few hours up to days. This requirement is crucial processes low cross sections characterization fully differential photoelectron(s) photoion(s) angular energy distributions. We demonstrate that...
We present a high-repetition rate, atttosecond light source, emitting controlled short trains of attosecond pulses. apply this source to the study photoionization atoms using 3D photoelectron/ion coincidence spectrometer.