Directional terahertz beam generation under interaction of an intense femtosecond laser pulse with a cluster jet

A supersonic jet consisting of atomic clusters of noble gases under interaction with high-power femtosecond radiation allows control of the radiation pattern and efficiency of generation of terahertz (THz) radiation. The laser filament formed in this jet is spatially defined by the shape of the jet. The concentration, spatial distribution, and size of the clusters influence the propagation of the femtosecond laser pulse in it and the formation of a THz pulse. We show that a specially formed cluster jet allows the shaping of THz radiation with a high degree of directionality and increase its intensity by more than 10 times.