Stable high-charge vortex dissipative solitons in azimuthally modulated waveguide arrays with localized gain

Abstract: We study the existence and dynamical properties of vortex solitons in Kerr media supported by azimuthally modulated waveguide lattices with localized gain and nonlinear loss. In this dissipative system, we find that the accessible topological charge of vortex solitons is strongly determined by the number of waveguide channels, with higher-order charges requiring progressively larger arrays. Power curves of vortex solitons with different charges exhibit clear separation in large arrays but become less distinguishable in smaller ones. Furthermore, these robust vortex solitons can be excited with nearly vanishing power thresholds, and higher-charge vortices display enhanced propagation stability compared with lower-charge states. These findings expand the family of dissipative vortex solitons supported by waveguide lattices and provide a route to the realization of stable high-symmetry vortex states.