RT Journal Article T1 Spectral self-action of THz emission from ionizing two-color laser pulses in gases A1 Cabrera Granado, Eduardo A1 Chen, Yxing A1 Babushkin, Ihar A1 Bergé, Luc A1 Skupin, Stephan AB The spectrum of terahertz (THz) emission in gases via ionizing two-color femtosecond pulses is analyzed by means of a semi-analytic model and numerical simulations in 1D, 2D and 3D geometries taking into account propagation effects of both pump and THz fields. We show that produced THz signals interact with free electron trajectories and thus significantly influence further THz generation upon propagation, i.e., make the process inherently nonlocal. This self-action contributes to the observed strong spectral broadening of the generated THz field. We show that diffraction of the generated THz radiation is the limiting factor for the co-propagating low frequency amplitudes and thus for the self-action mechanism in 2D and 3D geometries. PB IOP Publishing SN 1367-2630 YR 2015 FD 2015-02-18 LK https://hdl.handle.net/20.500.14352/24685 UL https://hdl.handle.net/20.500.14352/24685 LA eng DS Docta Complutense RD 13 may 2025