Strong-Field Dynamics Team

Dr. Boris Bergues

Research team leader

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
Klaas Von Der Brelje
Franz Haniel
Bsc. Maximilian Kubullek
Msc. Sambit Mitra
Msc. Philipp Rosenberger
Msc. Philipp Rupp
Dr. Shaohua Sun
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.