1. Max-Planck Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748, Garching, Germany 2. Department für Physik, Ludwig-Maximilians-Universit?t München, Am Coulombwall 1, 85748, Garching, Germany
Abstract:
We report on the pulse contrast-ratio characterization of a few-cycle 0.2 TW optical parametric chirped pulse amplifier system operating at 20 Hz. A specially designed third-order correlator was used to characterize and optimize the contrast of the system. We demonstrate that the pulse contrast depends much more on the temporal overlap between the pump and the seed pulse than the shape of the amplified spectrum. The best amplified pulse contrast-ratio was 10-4 at Δt=±25 ps and >10-9 at Δt=±150 ps delays. PACS 42.65.Vj; 42.65.Re