Spatio-Temporal And Spectral Transformation Of Femtosecond Pulsed Beams With Phase Dislocation Propagating Under Conditions Of Self-Action In Transparent Solid-State Dielectrics

Self-action of a femtosecond optical vortex in fused silica at a wavelength of 1900 nm is analyzed by means of numerical simulations. The formation of a multifocus ring structure is demonstrated. We show that self-focusing in a ring of relatively large radius occurs without plasma generation. The frequency spectrum of the pulse is broadening mainly into the Stokes band.