Time-resolved Photoelectron Spectroscopy
using ultrashort EUV Pulses

Our interest is the dynamics of elementary light-induced processes like photodissociation, photodesorption, photoemission and Auger-decay. Using ultrashort pulses in the extreme ultraviolet region (EUV-several tens of eV) rather than the traditional visible and UV range we gain access to the inner structure of an atom's electron shell.
Our experimental approach is based on a spectrally and temporally pure selection of High Harmonic radiation from fs laser pulses. A single harmonic order (n > 43) is selected with dedicated narrow-bandwidth multilayer optics with low group velocity dispersion. In contrast to more conventional grating monochromators, such device does not temporally broaden the pulse. The combination of a visible-pump EUV-probe excitation scheme with time-of-flight analysis of the emitted photoelectrons allows us to study the evolution of electronic processes in the gas phase and on surfaces on a fs-time scale.
In a collaboration with the Photonics Institute at the Technical University of Vienna and the Max-Planck-Institute for Quantum Optics in Garching even higher temporal resolution is obtained. Following transient changes of photoelectron kinetic energies as function of the phase between the EUV pulse intensity and the visible light-field, isolated EUV pulses of 250 as duration could recently be detected. These are the shortest single electromagnetic pulses ever created. These ultrashort light flashes allow the acquisition of snapshots of visible light ! Featuring both high photon energy and short duration such pulses were used to study the inner-shell relaxation of  atoms (MNN Auger-decay of krypton).

"Large-scale homogeneous molecular templates for femtosecond time-resolved studies of the guest–host interaction"
P. Siffalovic, M. Michelswirth, P. Bartz, B. Decker, C. Agena, C. Schäfer, S. Molter, R. Ros,
M. Bach, M. Neumann, D. Anselmetti, J. Mattay, U. Heinzmann, and M. Drescher
Journal of Biotechnology 112 (1-2): 139-149 AUG 26 2004

"Direct Measurement of Light Waves"
E. Goulielmakis, M. Uiberacker, R. Kienberger, A. Baltuska, V. Yakovlev, A. Scrinzi,
Th. Westerwalbesloh, U. Kleineberg, U. Heinzmann, M. Drescher, and F. Krausz
Science 305 (5688): 1267-1269 AUG 27 2004

"Atomic transient recorder"
Kienberger R, Goulielmakis E, Uiberacker M, Baltuska A, Yakovlev V, Bammer F, Scrinzi A,
Westerwalbesloh T, Kleineberg U, Heinzmann U, Drescher M, Krausz F
Nature 427 (6977): 817-821 FEB 26 2004

"Femtosecond time-resolved core-level photoelectron spectroscopy tracking surface photovoltage transients on GaAs"
P. Siffalovic, M. Drescher, U. Heinzmann,
Europhys. Lett., 60 (6) , pp. 924-930 (2002)

"Time-resolved atomic inner-shell spectroscopy"
Drescher M, Hentschel M, Kienberger R, Uiberacker M, Yakovlev V, Scrinizi A,
Westerwalbesloh T, Kleineberg U, Heinzmann U, Krausz F
Nature 419 (6909): 803-807 OCT 24 2002

"Steering attosecond electron wave packets with light"
Kienberger R, Hentschel M, Uiberacker M, Spielmann C, Kitzler M, Scrinzi A, Wieland M,  Westerwalbesloh T,
Kleineberg U, Heinzmann U, Drescher M, Krausz F
Science 297 (5584): 1144-1148 AUG 16 2002

"Sub-femtosecond X-ray pulse generation and measurement"
Kienberger R, Hentschel M, Spielmann C, Reider GA, Milosevic N, Heinzmann U, Drescher M, Krausz F
Applied Physics B - Lasers and Optics 74: S3-S9 Suppl. S JUN 2002

"Applicability of monochromatized high harmonic extended ultraviolet radiation for inner-shell photoelectron spectroscopy"
Drescher, M.; Siffalovic, P.; Spieweck, M.; Heinzmann, U.
Journal of Electron Spectroscopy and Related Phenomena, Volume: 127, Issue: 1-2, November, 2002, pp. 103-108

"Attosecond metrology"
M. Hentschel, R. Kienberger, Ch. Spielmann, G.A. Reider, N. Milosevic, T. Brabec, P.B. Corkum,
U. Heinzmann, M. Drescher and F. Krausz,
Nature 414 , 509 (2001)

"X-ray Pulses Approaching the Attosecond Frontier"
M. Drescher, M. Hentschel, R. Kienberger, G. Tempea, Ch. Spielmann, G. A. Reider, P. B. Corkum, and F. Krausz,
Science 291 , 1923 (2001)

"Laser-based Apparatus for Extended Ultraviolet  Femtosecond Time-resolved Photoemission Spectroscopy"
P. Siffalovic, M. Drescher, M. Spieweck, T. Wiesenthal, Y.C. Lim, R. Weidner, A. Elizarov, and U. Heinzmann,
Review of Scientific Instruments 72 , 30 (2001)