Controlling directivity pattern and intensity of THz radiation during its generation in a gas-clatter jet

A supersonic jet consisting of noble gas clusters is considered as a source of terahertz (THz) radiation pumped by high-power femtosecond laser system. We present the results of experimental studies on optimizing the intensity and diagram pattern of the THz radiation generated in cluster jet and demonstrate that under certain conditions of the jet excitation, it is possible to form a cluster filament that radiates THz waves with a maximum intensity along the direction of the laser beam propagation. Provided phenomenological model is in a good agreement with experimental results and well explains observed phenomenon.