Düsseldorf 2007 – wissenschaftliches Programm
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K: Fachverband Kurzzeitphysik
K 8: Lichtquellen und Röntgenlaser
K 8.1: Vortrag
Dienstag, 20. März 2007, 16:30–16:45, 6E
Cross-correlator for laser-timing measurements at FLASH — •Stefan Cunovic1, Theophilos Maltezopoulos2, Ulrike Frühling2, Harald Redlin2, Elke Plönjes-Palm2, Josef Feldhaus2, Roland Kalms3, Maria Krikunova3, Marek Wieland3, Norbert Müller1, and Markus Drescher3 — 1University of Bielefeld, 33615 Bielefeld — 2HASYLAB at DESY, 22607 Hamburg — 3University of Hamburg, 22761 Hamburg
The Free-Electron Laser in Hamburg (FLASH) delivers intense fs-laser pulses with high photon energies. In combination with a synchronized 800 nm fs-laser pump-probe experiments with a temporal resolution in the fs regime are possible. Currently, the ultimate resolution given by the pulse duration is not accessible due to a temporal jitter of the FLASH pulses. Here we present a cross-correlation scheme applicable in the VUV range for measuring the VUV-IR delay of individual pulses. Both pulses are crossed perpendicularly in a rare gas target. For simultaneous spatial and temporal overlap photoelectrons are subject to an energetic modulation introduced by the IR-laser field. By means of an electron optical system a two-dimensional electron image of the cross-correlation volume is formed. Thus, mapping the temporal onto the spatial coordinate allows for deducing information about the relative timing of both pulses. Currently, the cross-correlation signal level requires averaging over several FEL pulses. The set-up, however, carries the potential for a single-shot analysis, enabling pulse-to-pulse jitter measurements. In addition, it is applicable for any kind of ionizing radiation and is non invasive for both pulses.