Concentration and Propagation of Superstrong Laser-Induced THz Fields on a Microwire Target

The effect of a high-power short laser pulse from the Exawatt Center for Extreme Light Studies (XCELS) facility on solid-state metal targets with different constructions and sizes can yield high-power THz pulses with an unprecedentedly high energy. Their further application requires focusing and transport, which calls for the development of corresponding control units. In this context, it is of interest to use targets, which, on the one hand, are elements of the radiation source and, on the other hand, can collimate and transfer the THz radiation energy. A target in the form of a thin wire appears promising for this purpose. The process of THz pulse generation upon interaction between XCELS laser pulses and a metal cylindrical target (microwire) has been numerically simulated. It is shown that THz radiation is generated in a unique form (as a unipolar pulse) and the microwire target allows to concentrate a significant part of the radiation near its surface and transfer it (in the form of a unipolar surface pulse as well) with the speed of light along the wire to large distances with weak damping.