Fundamental and vortex dissipative quadratic solitons supported by spatially localized gain

We consider settings providing the existence of stable two-dimensional (2D) dissipative solitons with zero and nonzero vorticity in optical media with quadratic (chi((2))) nonlinearity. To compensate the spatially uniform loss in both the fundamental-frequency (FF) and second-harmonic (SH) components of the system, a strongly localized amplifying region [hot spot (HS)] carrying the linear gain, is included, acting on either the FF component or the SH one. In both cases, the Gaussian radial gain profile supports stable fundamental dissipative solitons pinned to the HS. The structure of existence and stability domains for the 2D solitons is rather complex. They demonstrate noteworthy features, such as bistability and spontaneous symmetry breaking. A ring-shaped gain profile acting on the FF component supports stable vortex solitons, with the winding number up to 5, and multipoles. Nontrivial transformation of vortex-soliton profiles upon either growth of the gain value or stretching of the gain profile is observed.

Automated summary

This article investigates the existence of stable two-dimensional dissipative solitons in optical media with quadratic nonlinearity. The authors introduce a localized amplifying region to compensate for loss in the system. The results demonstrate the stable solitons and vortex solitons that can be supported by implementing the appropriate gain distribution.