Quasi-periodic transformations of nonlocal spatial solitons

Abstract

We study quasi-periodic transformations between nonlocal spatial solitons of different symmetries triggered by modulational instability and resembling a self-induced mode converter. Transformation dynamics of solitons with zero angular momentum, e.g. the quadrupole-type soliton, reveal the equidistant spectrum of spatial field oscillations typical for the breather-type solutions. In contrast, the transformations of nonlocal solitons carrying orbital angular momentum, such as 2x3 soliton matrix, are accompanied by their spiralling and corresponding spectra of field oscillations show mixing of three characteristic spatial frequencies.

Self-Induced Mode Transformation in Nonlocal Nonlinear Media

“…Nevertheless, recent results suggest that spatial nonlocality of the nonlinear response can support higher-order solitons [20][21][22][23][24], similar to HG and LG modes [25]. Numerical studies revealed surprising nonlinear dynamics with quasiperiodic transformation between solitons of different symmetries [25][26][27], affected by anisotropic boundaries [28]. The conversion [27] can be seen as a continuous deformation along the family of generalized Gaussian beams [29], which includes HG and LG modes as two limiting cases.…”

“…Numerical studies revealed surprising nonlinear dynamics with quasiperiodic transformation between solitons of different symmetries [25][26][27], affected by anisotropic boundaries [28]. The conversion [27] can be seen as a continuous deformation along the family of generalized Gaussian beams [29], which includes HG and LG modes as two limiting cases. An alternative interpretation, based on detailed stability analysis [30], has revealed quasiperiodic and homoclinic orbits in the nonlinear transformation dynamics, induced by symmetry-breaking excitations.…”

Stability of multipole-mode solitons in thermal nonlinear media

“…The nonlinear response of a NLC is characterized by a finite nonlocality degree, thus when the size of the sample is large enough relative to the spatial extent of the light, the boundary of a NLC does not affect the light dynamics or soliton properties. In contrast, in a thermal medium, the nonlinear response is always greatly determined by the details of heat diffusion at sample boundaries and thus the nonlocality degree is naturally "infinite" as the afar boundaries could significantly change the light dynamics and soliton properties [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25], even when the spatial extent of the light beam is significantly small compared with that of the sample. Especially, numerical simulations [12] have demonstrated that the soliton stability may depend crucially on the sample geometry and a rectangular sample with a proper aspect ratio may stabilize the otherwise unstable dipole modes in a square sample.…”

Investigation on Propagation Characteristics of Super-Gaussian Beam in Highly Nonlocal Medium

“…Extensive investigations on strongly nonlocal media have given many new phenomena such as large phase shift [14], attraction between outof-phase solitons [3,9,30,41], attraction between dark solitons [29], and long-range interaction between solitons [22], etc., which are different from local solitons. In strongly nonlocal media, the beam always evolves periodically during propagation [38].…”