Three-dimensional solitons in cross-combined linear and nonlinear optical lattices

The existence and stability of three-dimensional (3D) solitons, in cross-combined linear and nonlinear optical lattices, are investigated. In particular, with a starting optical lattice (OL) configuration such that it is linear in the x-direction and nonlinear in the y-direction, we consider the z-direction either unconstrained (quasi-2D OL case) or with another linear OL (full 3D case). We perform this study both analytically and numerically: analytically by a variational approach based on a Gaussian ansatz for the soliton wavefunction and numerically by relaxation methods and direct integrations of the corresponding Gross-Pitaevskii equation. We conclude that, while 3D solitons in the quasi-2D OL case are always unstable, the addition of another linear OL in the z-direction allows us to stabilize 3D solitons both for attractive and repulsive mean interactions. From our results, we suggest the possible use of spatial modulations of the nonlinearity in one of the directions as a tool for the management of stable 3D solitons.

European Community Framework Programme

European Community Framework Programme [PIIF-GA-2009-236099]

Fundacao de Amparo a Pesquisa de Sao Paulo (FAPESP)

Fundacao de Amparo a Pesquisa de Sao Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Ministero dell Istruzione, dell Universita e della Ricerca (MIUR) through Programma di Ricerca Scientifica di Rilevante Interesse Nazionale (PRIN) initiative

Ministero dell' Istruzione, dell' Universita e della Ricerca (MIUR) through Programma di Ricerca Scientifica di Rilevante Interesse Nazionale (PRIN) initiative