Optimization of terahertz production from femtosecond multi- and superfilaments in air

The experimental results of energy deposition into the medium measurements and THz radiation measurements in case of two-color filamentation and filamentation in the presence of external electric field are presented. We considered different focusing conditions (NA=0.00218..0.00014) with the size of the beam equals to 8 mm. Two-color radiation was made by placing BBO crystal into the converging beam.