title: Power-dependent shaping of vortex solitons in optical lattices with spatially modulated nonlinear refractive index.
abstract: We address vortex solitons supported by optical lattices featuring modulation of both the linear and nonlinear refractive indices. We find that when the modulation is out of phase the competition between both effects results in remarkable shape transformations of the solitons that profoundly affect their properties and stability. Nonlinear refractive index modulation is found to impose restrictions on the maximal power of off-site solitons, which are shown to be stable only below a maximum nonlinearity modulation depth.
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, and Universitat Politecnica de Catalunya, Mediterranean Technology Park, Barcelona, Spain. yaroslav.kartashov@icfo.es
authors.forename: Yaroslav V
authors.initials: YV
authors.lastname: Kartashov
authors.forename: Victor A
authors.initials: VA
authors.lastname: Vysloukh
authors.forename: Lluis
authors.initials: L
authors.lastname: Torner