München 2004 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
Q: Quantenoptik und Photonik
Q 5: Ultrakurze Lichtimpulse: Attosekundenpulse
Q 5.6: Vortrag
Montag, 22. März 2004, 15:30–15:45, HS 223
Towards Attosecond Half-Cycle Pulses — •Emil Persson1, Severin Puschkarski1, Xiao-Min Tong2, and Joachim Burgdörfer1 — 1Institute for Theoretical Physics, Vienna University of Technology — 2Department of Physics, Kansas State University
Present techniques for producing half-cycle pulses (HCP) are limited to widths of 500fs, which limits impulsely shaping and manipulating of wave packets to Rydberg states n≫ 1. We theoretically analyze a protocol for producing HCP in the attosecond regime [1]. Such pulses in a pump-probe setting would allow to impulsely drive, probe, shape and control electronic wave functions near the ground state [2].
We study the harmonics generated by the non-linear interaction of an atom with strong two-color fields (HHG) in single atom response. To form HCP, the phases of all harmonics, starting from the fundamental, should be aligned. Varying the strength and amplitudes of the two-color driving field, we find that it is possible to align the phases of the lowest harmonics up to the energy necessary to excite the first higher state. For helium we find HCP with a width as short as 280as.
Depending on the length and carrier-envelope phase of the driving field, we find (a) trains consisting of hundreds of HCP, (b) single HCP with only small side-wings, and (c) trains consisting of two HCP with variable strengths and delay between the pulses. The findings (b, c) imply possibilities for attosecond impulsive pump-probe experiments.
Work supported by the Austrian FWF under contract No. SFB-016