Terahertz radiation generation by a soliton in a laser-plasma system

In recent years, there has been considerable interest in exploiting intense laser-plasma interactions for generating terahertz (THz) radiation[1,2]. In the present study, we propose a novel mechanism that is based on the creation of a localized `soliton’ structure due to the interaction of the laser pulse with the plasma [3]. A population of oscillating electrons trapped inside this localized cavity then acts as a dipole antenna to emit radiation whose frequency lies in the THz range. We demonstrate this mechanism through detailed particle-in-cell simulations. The configuration of the laser-plasma system can be suitably arranged to form the localized structure near the plasma vacuum boundary so that the radiation can propagate to the vacuum without getting fully absorbed within the plasma. THz generation through such a mechanism has advantages over other conventional schemes on account of its compact size and high damage threshold limit.