Strong-Field Dynamics Team

Dr. Boris Bergues

Research team leader
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Curriculum Vitae List of publications

Research interests

  • Imaging of ultrafast processes in atoms and molecules
    • Electron Imaging Spectroscopy (VMI)
    • Electron Ion Coincidence Momentum Spectroscopy (COLTRIMS)
    • Nonlinear interactions of matter with attosecond XUV pulses
    • Generation of intense attosecond XUV pulses
    • Ion microscopy
    • Theory of strong field processes
    • Semiclassical calculations
    • Quantum trajectory approaches
    • TDSE, TDDFT
    • Strong field processes in solids
    • Light driven currents in solid materials
    • Time domain THz spectroscopy

Team members

Msc. Najd Altwaijry
Msc. Ritika Dagar
Franz Haniel
Msc. Weiwei Li
Msc. Sambit Mitra
Msc. Philipp Rosenberger
Dr. Philipp Rupp
Dr. Zilong Wang

What happens when matter is exposed to intense laser pulses with electric fields comparable to those holding the electrons bound to the nuclei? How can we use such strong electric fields to control and steer the electron motion with a precision reaching down into the attosecond time scale? These are questions addressed in the strong field physics team. We are working with different experimental setups to investigate these questions in various materials, ranging from atoms and molecules to solids. The work horse of our experimental research are ultrashort laser pulses generated with state-of-the-art laser systems, and with durations barely longer than a single light wave oscillation.

Current Projects

3D Coincidence momentum spectroscopy

In the COLTRIMS (COLd Target Recoil Ion Momentum Spectroscopy) project, the interaction of near single cycle laser pulses with atoms and molecules is studied by measuring the momentum of the fragments (electrons and ions) in coincidence. The combination of COLTRIMS with single-shot carrier-envelope phase measurements enables the control of ionization and dissociation processes with sub-cycle temporal resolution.

 

Ion Microscopy

When ultrashort and intense laser pulses are focused onto an atomic gas, different ionic charge states are generated upon multiple photoionization. The spatial distribution of the different charge states depends on the intensity distribution in the laser focus. By spatially resolving the charge state distribution, our ion microscopy technique provides access to intensity resolved ion yields. The technique is particularly well suited to studying ultrafast light-matter interactions in the XUV spectral range. It has recently allowed the first demonstration of nonlinear interactions between attosecond XUV pulses and core electrons in xenon.

Reaction Nanoscopy

Reaction nanoscopy is a novel technique designed to study the interaction of few-cycle laser pulses with nanoparticles and molecules adsorbed on their surface. Nanoparticles are of great interest in nanochemistry since they offer unique properties as photo-catalysts due to their large surface area. Enhanced near-fields, induced on the nanoparticle’s surface under irradiation with ultrashort light pulses can be used to control molecular photoionization and dissociation reactions on the nanoscale.

Ultrafast Currents

In the ultrafast current project, we explore alternative routes for the measurement of the carrier-envelope phase (CEP) of few-cycle laser pulses that rely on strongly driven currents in solid-state samples. Beyond the application to CEP measurements, we take advantage of the information contained in the CEP-dependent current to gain a deeper understanding of the electron dynamics in various solid materials exposed to strong few cycle laser pulses.

Thesis Supervision / Co-Supervision

PhD students:

2018 − present Philipp Rosenberger: Ultrafast imaging of molecular reactions using electron-ion coincidence spectroscopy.

2017 − present Sambit Mitra: Reaction Nanoscopy of molecular reactions on the surface of nano-spheres.

2016 − 2019 Philipp Rupp: Ultrafast dynamics on nanostructures in strong fields.

2016 − 2018 Christian Burger: Laser Induced Isomerization of Hydrocarbons.

2012 − 2016 Daniel Rivas: Generation of Intense Isolated Attosecond Pulses at 100 eV.

2010 − 2014 Matthias Kübel: Single-Cycle Non-Sequential Double Ionization.

2008 − 2011 Oliver Herrwerth: Atomic and Molecular Ionization Dynamics in Strong IR and XUV Fields Probed by Time-Resolved Coincidence Spectroscopy.

2008 − 2012 Irina Znakovskaya: Light-Waveform Control of Molecular Processes.

MSc students:

2017 − 2018 Thomas Weatherby: Reaction Nanoscopy: Near-Field-Induced, Dissociative Ionisation from Nanoparticles in Solution.

2017 − 2018 Philipp Rosenberger, Control of quantum dynamics in H2 by ultra-short phase-stable laser pulses.

2016 − 2017 Wilhelm Frisch: Multi Color Control of Strong Field Ionization.

2014 − 2015 Alexander Muschet: Ion Microscopy for Attosecond XUV Pulse Diagnostics.

2007 Till Hause: Characterization of a GRENOUILLE.

BSc students:

2019 − present Franz Haniel: Development of a new ion microscope design using machine learning tools.

2018 − 2019 Klaas von der Brelje: Ultrafast Dynamics in Nano-layer Materials.

2017 − 2018 Max Kubullek: CEP measurement of circularly polarized laser pulses in fused silica.