Higher-Charged Vortex Solitons in Harmonic Potential

By introducing external harmonic potential confinement, we investigate the stability of higher-charged vortex solitons in competing cubic–quintic nonlinear medium. Vortex solitons with higher charges (m > 5) become robust in harmonic potential. There are two coexisting branches of different power at the same propagation constant domain. Intriguingly, if topological charge m > 1, we find the inferior branch of solitons is completely unstable, while the superior branch of solitons still exists interval of stability with the enhancement of competing nonlinearity. From the perspective of the numerical results, it reveals a novel approach to access optical vortex mode with higher topological charge.