Two-dimensional vector solitons stabilized by a linear or nonlinear lattice acting in one component

O. V. Borovkova^1a, B. A. Malomed² and Y. V. Kartashov¹

¹ ICFO-Institut de Ciencies Fotoniques, and Universitat Politecnica de Catalunya, Mediterranean Technology Park 08860 Castelldefels, Barcelona, Spain, EU
² Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University Tel Aviv 69978, Israel

^a olga.borovkova@icfo.es

Received: 3 August 2010
Accepted: 28 November 2010

Abstract

The subject of the work is the stabilization of two-dimensional (2D) two-component (vector) solitons, in media with the attractive cubic nonlinearity, against the collapse by a linear lattice (LL, which is induced by a periodic modulation of the refractive index in optics, or created as an optical lattice in BEC), or by a nonlinear lattice (NL, induced by a periodic modulation of the nonlinearity coefficient). We demonstrate that, due to the XPM (cross-phase-modulation) coupling between the components, the LL or NL acting on a single component is sufficient for the stabilization of vector solitons, that include a component for which the self-focusing medium is uniform. In the case of the LL, the vector solitons are stable almost in their entire existence domain, while the NL can only stabilize the solitons in which the component affected by the lattice carries a norm which is comparable to, or larger than the norm of the component in the uniform medium.