THz Generation in Laser Filament under Electric Field Conditions

We present experimental study results of THz range radiation generation in a laser plasma. Comparison of one and two-color optical pumping schemes is presented. Dependence of THz radiation energy from the electrical field application point to filament is shown. The maximum generation efficiency is observed when an electric field is applied to geometrical focus point (laser filament is formed before geometrical focus point). The mechanisms of this effect are discussed.