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search.filters.applied.f.access: openAccess × Type: Text × Publisher: Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik × Subject: Ultrashort pulse propagation × WGL Institute: MBI ×

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Now showing 1 - 3 of 3
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    Plasma induced pulse breaking in filamentary self-compression
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2009) Brée, Carsten; Demircan, Ayhan; Skupin, Stefan; Berg´e, Luc; Steinmeyer, Günter
    A plasma induced temporal break-up in filamentary propagation has recently been identified as one of the key events in the temporal self-compression of femtosecond laser pulses. An analysis of the Nonlinear Schrödinger Equation coupled to a noninstantaneous plasma response yields a set of stationary states. This analysis clearly indicates that the emergence of double-hump, characteristically asymmetric temporal on-axis intensity profiles in regimes where plasma defocusing saturates the optical collapse caused by Kerr self-focusing is an inherent property of the underlying dynamical model.
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    Ultrafast spatio-temporal dynamics of terahertz generation by ionizing two-color femtosecond pulses in gases
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2010) Babushkin, Ihar; Kuehn, Wihelm; Köhler, Christian; Skupin, Stefan; Bergé, Luc; Reimann, Klaus; Woerner, Michael; Herrmann, Joachim; Elsaesser, Thomas
    We present a combined theoretical and experimental study of spatio-temporal propagation effects in terahertz (THz) generation in gases using two-color ionizing laser pulses. The observed strong broadening of the THz spectra with increasing gas pressure reveals the prominent role of spatio-temporal reshaping and of a plasma-induced blue-shift of the pump pulses in the generation process. Results obtained from (3+1)-dimensional simulations are in good agreement with experimental findings and clarify the mechanisms responsible for THz emission.
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    Self-compression of 120 fs pulses in a white-light filament
    (Berlin : Weierstraß-Institut für Angewandte Analysis und Stochastik, 2010) Bethge, Jens; Steinmeyer, Günter; Stibenz, Gero; Staudt, Peter; Brée, Carsten; Demircan, Ayhan; Redlin, Harald; Düsterer, Stefan
    Self-compression of pulses with >100 fs input pulse duration from a 10 Hz laser system is experimentally demonstrated, with a compression factor of 3.3 resulting in output pulse durations of 35 fs. This measurement substantially widens the range of applicability of this compression method, enabling self-compression of pulsed laser sources that neither exhibit extremely low pulse-to-pulse energy fluctuations nor a particularly clean beam profile. The experimental demonstration is numerically modeled, revealing the exact same mechanisms at work as at shorter input pulse duration. Additionally, the role of controlled beam clipping with an adjustable aperture is numerically substantiated