Femtosecond laser filament in different air pressures simulating vertical propagation up to 10 km

Using a femtosecond Ti:Sapphire laser we experimentally and numerically simulated in the laboratory vertical propagation and filamentation in the atmosphere for up to 10 km by changing the pressure in a gas cell. Filament diameter increased at reduced pressures in air. This is a manifestation of the invariance of intensity clamping. Filaments produced at low pressures corresponding to higher altitudes were shown to reveal excellent transport properties due to the wide low-density plasma column extended homogeneously over long propagation distances.