Specifics of multiple filamentation formation for femtosecond laser radiation with topological charge

Abstract

Evolution of local instability in a ring vortex beam propagating in the turbulent atmosphere with highest nonlinearities of the refractive index as well as in uence of the effective characteristics of the light beam is investigated based on numerical calculation of the nonlinear Schrodinger equation with high-order nonlinearities. Propagation of high-power femtosecond laser radiation (HPFLR) with topological charge in the random medium under overlap of an amplitude-phase mask and an original beam is considered. Depending on the mask configuration and initial radiation power, rotation of the beam can lead both to converge and growth more distant of filamentation beginning as well as extension of filamentation area by two and more times.