Rotating asymmetric solitons in competing nonlinear media

Abstract

We predict a novel family of off-center localized nonlinear modes in a rotating optical system. The whispering-gallery-like solitons bifurcate out from the symmetric fundamental solitons through a symmetry breaking. They can appear as localized spots, nearly flat-top beams and crescent-like patterns extending over the entire range of polar angles. At critical rotation frequency, asymmetric solitons transform into vortex solitons, whose topological charge gradually increases with the growth of the propagation constant. Asymmetric solitons rotate around the origin persistently during propagation and preserve their shape over arbitrary distance in almost the whole existence domain. Thus, we put forward the first example of stable asymmetric intermediate states in optical systems that bridge the symmetric fundamental solitons and the symmetric vortex solitons with different topological charges, through the variance of the propagation constant and rotation frequency.