Phase matched terahertz emission from magnetized plasma via optical rectification of a Gaussian laser pulse with triangular intensity spatial profile
Year: 2026
Type: article
Abstract: The emission of terahertz (THz) radiation from an axially magnetized, density-modulated plasma under the normal incidence of a right circularly polarized Gaussian laser pulse, whose spatial intensity profile has a triangular shape, is studied. The nonuniform intensity profile of the incident beam causes a quasistatic ponderomotive force on the plasma electrons in the transverse direction of the laser pulse propagation. When the pulse width is tuned such that, its inverse lies in the THz, the plasma electrons are driven into collective oscillations. The nonlinear velocity experienced by the electrons because of the ponderomotive force is coupled with the density ripple, resulting in a nonlinear current density, which is the source of the emitted THz wave. In the presence of a static magnetic field, the dispersion relation of plasma waves is changed, which allows tuning of the generated THz frequency and an increase in its amplitude. The density ripple further helps by matching the phase of the incident laser with the generated THz wave. The enhancement in the amplitude of the THz waves is due to the fact that the electron cyclotron frequency provides a resonant condition in which the cyclotron frequency and the THz wave frequency reinforce the electron oscillations, which increases the amplitude of the emitted THz waves.
Source: Laser Physics
Institutions: Siddhartha University, Aligarh Muslim University
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W7215126246