Observation of early and strong relativistic self-focusing of cosh-Gaussian laser beam in cold quantum plasma

Relativistic self-focusing of cosh-Gaussian laser beam in the cold quantum plasma has been investigated theoretically using Wentzel-Kramers-Brillouin (WKB) and paraxial ray approximation. The comparative study between self-focusing of cosh-Gaussian laser beam in cold quantum case and classical relativistic case has been made for decentered parameter b = 0.9 and it is observed that as the beam propagates deeper inside the cold quantum plasma, the self-focusing ability of the laser beam enhances and shifted towards lower value of normalized propagation distance due to quantum contribution. The variation of beam width parameter with normalized propagation distance for various values of relative density parameter of the medium and intensity parameter has also been studied. It is observed that with the increase in the value of relative density parameter, self-focusing of laser beam becomes stronger. Observation of early and strong self-focusing for higher values of relative density parameter and intensity parameter are reported. Also, with the increase in the value of the relative density parameter of the medium and intensity parameter, self-focusing ability shifted towards lower value of normalized propagation distance due to relativistic effect. The present study might be very useful in the applications like the generation of inertial fusion energy driven by lasers, laser driven accelerators, scribing type of applications in electronics etc. (author)