High-intensive femtosecond singular pulses in Kerr dielectrics

Abstract

The nonlinear dynamics of a high-power femtosecond singular pulse in Kerr media are analyzed numerically upon optically induced ionization. We examine the plasma inertia impact to stable propagation of optical vortices. Multifoci behavior of vortices in medium are revealed. Next we numerically demonstrate that inertial character of plasma formation provides a quasi-soliton regime of vortex propagation resistant to symmetry-breaking perturbation.

Powerful femtosecond singular pulses in the Kerr media with dispersion

“…Being interested in the stable propagation of the pulsed vortex beams in the medium, we search for the soliton or, at least, quasi-soliton solutions. As earlier shown in the work [8], the competition of the Kerr focusing and the defocusing plasma nonlinearities can provide quasisoliton regime of the vortex propagation under negligible effect of the GVD. Fig.…”

“…It should be noted that inclusion of the GVD makes possible pulse refocusing for larger ratios  than those typical for the case when the dispersion is completely absent [8]. We would recall in this respect that the multifoci scenario observed in our previous work takes place at  =15.57 or even smaller values.…”

“…In our previous work [8] we have investigated the propagation of highly intense femtosecond singular pulses in a Kerr medium, depending on the topological charge and the ratio of initial and critical pulse powers. We have found that the underlying physical mechanism for stable vortex propagation is dynamic competition between a Kerr self-focusing and a defocusing caused by plasma due to multi-photon ionisation processes.…”

“…The stability of the vortex beam against azimuthal perturbations has been elucidated, too. The main results obtained in the study [8] may be formulated as follows. It is the competition of the focusing and defocusing factors at weak dissipation and especially the inertial character of plasma that can provide a quasi-soliton regime of propagation for the pulsed femtosecond vortex beams.…”

Interaction of laser-generated polarization singularities in a nonlinear isotropic gyrotropic medium

“…Moreover, numerical investigations have shown that the nonlocality of nonlinear medium plays the key role in the stabilization of the propagation of singular beams of specific type [21][22][23]. The interest to the processes accompanying the filamentation of singular beams also increases [24,25].…”