Magnetically tuned hybrid resonance emission of terahertz waves from the interaction of intense laser beams with warm collisional inhomogeneous plasma

Abstract

Enhancing the terahertz emission at hybrid resonant frequencies is observed from a warm collisional inhomogeneous plasma irradiated by intense laser beams in the presence of an external transverse magnetic field. To reach this result, we utilize the dielectric permittivity tensor of the plasma affected by the strength and the direction of the magnetic field and analyze the nonlinear current density induced by the ponderomotive force due to the beating of two Gaussian laser beams. The calculations reveal resonance emission at several frequencies, which depend on the thermal speed of the electrons, the wavenumber, the electron plasma frequency, the collision frequency, and the cyclotron frequency. However, the amplitude of THz waves at these frequencies mainly depends on the electron temperature as well as the external magnetic field strength.