Spatiotemporal evolution of twisted Laguerre-Gaussian laser in magnetized plasma

Orbital angular momentum (OAM) carrying laser beams have gained interest because of their profound applications in the laser-plasma interaction, such as the generation of twisted harmonic beams, magnetic fields, accelerated particle bunches, and so on. In this article, considering spatiotemporal profile of an intense Laguerre-Gaussian beam (LGpl), we investigated the pulse evolution while propagating in a magnetized plasma. The oscillatory velocity of the plasma electrons is in the relativistic domain. We have also considered the hyperbolic tangent profile for laser chirping, as it has been found that the chirped profile is suitable for trapping electrons for longer periods. Using the Wentzel-Kramers-Brillouin (WKB) approximation, we have derived two coupled differential equations associated with the laser spot size and pulse width. The effect of laser OAM has been investigated for the simultaneous evolution of laser spatial and temporal profiles. Lasers with higher OAM show delays in the transverse focusing and longitudinal compression while propagating. The self-trapped condition is derived, showing a dependence on the laser OAM and chirping parameter. The pulse evolution in the plasma also depends on the initial intensity and pulse duration of the laser. Earlier compression is observed for the laser beams with lower intensity and smaller pulse duration.