Stable counter-rotating vortex pairs in saturable media
نویسندگان
چکیده
We resolve a controversial issue of the stability of composite vortex solitons in self-focusing saturable nonlinear media. Stable vortex solitons with hidden angular momentum, i.e., composed of counter-rotating beams with topological charges +1 and −1, are found, and their linear-stability region is identified. In contrast, the solitons with explicit vorticity are always unstable against splitting. The predicted linear stability of the hiddenvorticity solitons is achieved in the strong-saturation regime, when the soliton’s total power exceeds a certain threshold. The dynamical stability is verified in direct simulations of nonlinear model. © 2006 Elsevier B.V. All rights reserved. PACS: 42.65.Tg; 42.65.Jx; 03.65.Vf
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