New approach to the problem of THz generation by intense two-color laser fields

Abstract

In this paper we propose a new approach to the problem of the generation of electromagnetic radiation of the terahertz bandwidth in nonequilibrium plasma channels created by high-intensity laser radiation in gases. The key idea of the proposed approach consists in superimposing additional amplification to the laser-induced generated THz pulse due to the specific properties of the nonequilibrium plasma channel. We perform a self-consistent analysis of the processes of terahertz pulse formation by the four-wave mixing process and its 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 a terahertz pulse.