Our research interests are related to the theory of ultrafast processes in atoms, molecules and nanostructures induced, observed and controlled by ultrashort intense laser pulses. Electric field strengths of such laser pulses can exceed those of the Coulomb fields within an atom or molecule while the pulse durations are as short as a few femtoseconds (10-15 s) or even shorter. Laser frequencies range from the far-infrared through the optical to the soft x-ray region. Recent results of our research include:
Isolated Circularly Polarized Attosecond Pulses
We have proposed two schemes to generate isolated attosecond pulses of pure circular polarization ... read more.
Role of Group Velocity Matching
According to our theoretical analysis, group velocity matching between the laser field and the X-ray field play a major in the generation of high-order harmonics and attosecond pulses at mid-infrared wavelengths ... read more.
Attosecond High Harmonic Spectroscopy
Signals of high harmonic generation show signatures of the nonadiabatic electron dynamics in molecules ... read more.
Delayed Resonant Two-Photon Ionization
We have proposed how the attosecond streaking camera technique can be used to retrieve time delays in resonant two-photon ionization ... read more.
Breakdown of Power Series Expansion
We have explored the limits of the traditional power series expansion of the nonlinear susceptibility ... read more.
We frequently utilize in our work the Janus supercomputer, which is a joint effort of the University of Colorado Boulder, the University of Colorado Denver and the National Center of Atmospheric Research.