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A: Fachverband Atomphysik

A 24: Attosecond physics I

A 24.7: Vortrag

Donnerstag, 17. März 2011, 18:00–18:15, BAR 205

Sideband oscillation by two-color ionization experiments — •Alexander Sperl, Helga Rietz, Ram Gopal, Andreas Fischer, Konstantin Simeonidis, and Joachim Ullrich — MPI für Kernphysik, 69115 Heidelberg

Noble gas atoms can be ionized by irradiation with an extreme-ultraviolet (XUV) attosecond pulse train emitting electron wave packets. These pulses are synthesized from harmonics generated by focusing an infrared laser beam (IR with a pulse duration of 30 fs, single pulse energy of 0.6 mJ and wavelength at 777 nm) into an argon gas tube at a pressure of 80 mbar. Both the attosecond pulse train and the electron wave packets can be characterized by superimposing the XUV and the fundamental IR fields and considering the energy transfer to the electron wave packets as a function of time delay between both fields resulting in oscillating energy-sidebands, a technique referred to as RABBIT (reconstruction of attosecond beating by interference of two-photon transitions) [1], [2]. The three-dimensional dynamics of the photoelectrons however can now be studied in more detail by combining the XUV light source with a Reaction Microscope. In this context we changed the polarisation of the XUV and the IR fields with respect to each other by 90°, detecting a remarkable change of the angular distribution of the sideband-photoelectrons.

[1] H. G. Muller, et. al., Appl. Phys. B 74, 2002 [2] P. Johnsson, et. al., Journal of Modern Optics 53, 2006