(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.
