Attosecond physics

An image recorded with an attosecond streak camera.

Studying electron dynamics in the shell of ground-state atoms requires light pulses with a duration approaching the electron's "natural" time-scale. One (classical) roundtrip of the 1s-electron in hydrogogen, for example, takes 150 as, while the oscillation period of a visible light field already is reaches 2 fs. Soft X-rays at 10 nm wavelength, on the other hand, oscillate within only ~ 30 as - physically they therefore support the creation of sub-fs electromagnetic pulses. Utilizing a quantum-optical phenomenon, focussing of near- infrared few-cycle laser pulses into an atomic gas yields very high harmonic orders of the fundamental laser frequency. In collaboration with the groups of Prof. Ferencz Krausz at MPQ and Prof. Heinzmann at the University of Bielefeld, pulses as short as ~100 as are routinely generated, representing the shortest isolated light bursts ever created. We apply these pulses in studies of inner-shell electronic dynamics in atoms. The relaxation of highly excited atoms is followed directly in the time-domain. Collaborating institutions and scientific programs: Max-Planck-Institute for Quantum Optics, Garching Faculty of Physics, University of Bielefeld Photonics Institute, Technical University of Vienna Research Training Program GrK1335 at the University of Hamburg