Study of Terahertz Radiation Generation by Two Laser Beams in an Axial Magnetized Rippled Density Plasma

摘要

This paper presents a scheme to achieve terahertz radiation by the beating of top-hat lasers in a rippled density collisional magnetized plasma. The nonlinear current at terahertz frequency arises on account of nonlinear ponderomotive force as a result of beating of the two lasers. A uniform static magnetic field which is considered parallel to the direction of lasers leads to, depending on the phase-matching conditions, propagation of right-hand circularly polarized (RCP) or left-hand circularly polarized (LCP) waves in plasma. It is found that, terahertz amplitude of RCP wave for high values of beating frequency is slightly larger than LCP wave. The contribution of magnetic field, laser index and collision frequency are discussed for the efficient terahertz radiation generation. With the optimization of these parameters, the efficiency of order of 25 percent can be achieved in the present scheme.