Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
A: Fachverband Atomphysik
A 9: Interaction with VUV and X-ray light (FEL) II
A 9.6: Vortrag
Dienstag, 15. März 2011, 12:30–12:45, BAR 205
Laser-based terahertz-feld-driven streak camera for the tem- poral characterization of fs HHG pulses — •Bernd Schütte, Ulrike Frühling, Marek Wieland, Armin Azima, and Markus Drescher — Universität Hamburg, Hamburg, Germany
We report on a new measurement technique for the temporal characterization of femtosecond (fs) pulses from a high-order harmonic generation (HHG) source. This method is borrowed from attosecond metrology and was first transferred to the fs range at the Free Electron Laser in Hamburg (FLASH) [1]. On a laboratory scale, we now superimpose
the 59th order of a HHG source (λ = 13.5 nm) with terahertz (THz) pulses originating from optical rectification in a lithium niobate crystal
via the tilted-pulse front method (λ=250 µm) [2]. The generation of HHG and THz radiation with the same laser pulse ensures an inherent synchronization. In contrary to a conventional streak camera, rare gas
atoms serve as a photocathode, which are ionized by the HHG pulses. The created electrons are then accelerated by the THz feld, where the momentum gain depends on the THz phase at the ionization time. In this way, the temporal distribution of the HHG pulses is mapped into a
distribution of electron energies. By scanning the delay between HHG and THz pulses, the electric feld of the THz pulses could be sampled. In addition, a reconstruction of HHG pulse durations was performed at
low photon fluxes where techniques based on nonlinear autocorrelation do not work.
U. Frühling et al., Nature Photonics, Vol. 3, 523, 2009.
J. Hebling et al., Opt. Express, Vol. 10, 1161, 2002.