New Approach to THz Pulse Generation in Plasma Created by High-Intensity Laser Field

We propose new approach to the problem of generation of terahertz radiation in nonequilibrium plasma channels created by high-intensity laser radiation in gases. Key idea of the proposed approach lies in implementing additional amplification to the laser-induced generated THz pulse due to the specific properties of nonequilibrium plasma channel. We perform a self-consistent analysis of the processes of terahertz pulse formation by four-wave mixing process as well as by relaxation of residual low-frequency currents and it further propagation and amplification in a nonequilibrium plasma medium in a wakefield of the laser pulse. Optimal parameters for the pump laser pulse and gaseous medium are found for the most efficient conversion of its energy into terahertz pulse.