The interaction of light with matter has been a fundamental topic in the history of quantum theory and, as such, been investigated for more than a century. The study of the response of matter to electromagnetic radiation is nowadays closely related to the development of intense laser systems generating ultrashort light pulses. The strengths of these light fields exceed that of the Coulomb field within an atom or molecule while the pulse lengths have decreased below the femtosecond (10^-15 s) barrier and a new research area called attoscience evolved. Frequencies of available laser systems range from the far-infrared through the optical up to the vacuum-ultraviolet and the soft x-ray regions. Applications of ultrashort intense laser pulses in basic and applied research can be found in physics, chemistry and biology. We work on the theoretical analysis and numerical simulations of ultrafast processes in atoms, molecules and nanostructures, which can be observed and controlled using intense laser pulses. Our research activities are supported by the National Science Foundation, the Department of Energy and the Air Force Office of Scientific Research.

Recent highlights:

• When does an electron tunnel from the molecule in the oscillating strong field of a laser? The answer of this atto quiz can be found here or in a discussion of our work in NewScientist.
• The emission of two electrons from an atom due to absorption of a few photons follows selection rules, as can be seen here or in the LabTalk of J. Phys. B.