Second harmonic efficiency in elliptical polarized Bessel–Gaussian laser beam-cold magnetized quantum collisional plasma interaction

This study examines the effects of polarization states, including elliptical, circular (left- and right-handed), and linear, on the second harmonic efficiency (SHE) and Bessel–Gaussian laser self-focusing in preformed plasma. Utilizing the Wentzel–Kramers–Brillouin approximation and paraxial theory, we derive second-order differential equations governing the beam widths along an elliptical laser beam’s semimajor and semiminor axes. The investigation explores the influence of the laser’s transverse field component, the strength of an external magnetic field, polarization type, plasma collision mechanisms, and plasma regimes on the self-focusing length and depth. Results indicate that increases in the transverse laser profile component and external magnetic field intensity affect self-focusing. Polarization plays a crucial role: circular and elliptical polarizations alter the laser focusing distance, enhancing both the self-focusing depth and second harmonic generation efficiency. Right-handed circular polarization, in particular, facilitates the earlier onset of laser self-focusing and improves SHE. The initial laser beam achieves a focus sooner, which is especially helpful during electron-ion interactions, resulting in more incredible second harmonic growth than electron-diatomic molecule interactions. This research reveals that the quantum characteristics of plasma, contrasted with classical relativistic plasma, yield a modest reduction in focal length alongside an increase in self-focusing depth, further augmenting the SHE.