Third Harmonic Generation Of Cosh- Gaussian Laser Beam In Magnetized Plasma
摘要
In this current study, we have examined a cosh-Gaussian laser’s third harmonic generation (THG) within a magnetized plasma. As the laser traverses the plasma medium, electrons experience oscillatory velocities, leading to density perturbations. The resulting density oscillations interact with the oscillatory velocities, giving rise to a third harmonic current that facilitates the generation of the third harmonic signal. The introduction of a wiggler magnetic field imparts additional momentum to the third harmonic photons, ensuring compliance with the phase-matching condition and enabling resonant third harmonic generation. The wiggler field plays a dual role by not only contributing to the phase-matching condition but also sustaining the cyclotron frequency. Maintaining the cyclotron frequency enhances third harmonic production efficiency by keeping plasma electrons within the specified plasma zone. Through the utilization of the paraxial ray approximation, we derive the equation governing the amplitude of third harmonic generation and analyze its variations under different parameters, including the intensity of the incoming laser, wiggler magnetic field strength, decentred parameter, and plasma density. The paraxial ray approximation used in this study assumes that the laser beam’s amplitude and phase vary slowly along the propagation direction. This is valid for the cosh-Gaussian beam considered, given its beam width