%0 Journal Article %T Terahertz Radiation from a Longitudinal Electric Field Biased Femtosecond Filament in Air %+ Shanghai Key Lab of Modern Optical System %+ Laboratoire d'optique appliquée (LOA) %+ Centre d'Etudes Lasers Intenses et Applications (CELIA) %+ ELI Beamlines %A Liu, Yi %A Liu, Shaojie %A Houard, Aurélien %A Mysyrowicz, André %A Tikhonchuk, Vladimir, T %< avec comité de lecture %@ 0256-307X %J Chinese Physics Letters %I IOP Publishing %V 37 %8 2020 %D 2020 %R 10.1088/0256-307x/37/6/065201 %K laser filamentation %K ultrafast laser %K plasma %K laser %K terahertz %Z Physics [physics]/Physics [physics]/Optics [physics.optics]Journal articles %X The terahertz (THz) temporal waveform and spectrum from a longitudinal electrically biased femtosecond filament is studied experimentally. The initial direction of the electron motion inside the unbiased filament plasma is deduced from the transformation of the THz temporal waveform with applied fields of opposite polarities. Furthermore, a spectrum shift to lower frequency of the THz spectrum is observed in the presence of a biased field. It agrees well with theoretical predictions. %G English %2 https://hal-ensta-paris.archives-ouvertes.fr/hal-02993245/document %2 https://hal-ensta-paris.archives-ouvertes.fr/hal-02993245/file/THz%20longitudinal%20field_Liu_20200302.pdf %L hal-02993245 %U https://hal-ensta-paris.archives-ouvertes.fr/hal-02993245 %~ CEA %~ X %~ ENSTA %~ CNRS %~ X-LOA %~ X-DEP %~ X-DEP-PHYS %~ ENSTA_LOA %~ DSV %~ DAM %~ CEA-DRF %~ IP_PARIS %~ IP_PARIS_COPIE