Observation of higher-order solitons in defocusing waveguide arrays

Abstract

We observe experimentally higher-order solitons in waveguide arrays with defocusing saturable nonlinearity. Such solitons can comprise several in-phase bright spots and are stable above a critical power threshold. We elucidate the impact of the nonlinearity saturation on the domains of existence and stability of the observed complex soliton states.Comment: 13 pages, 3 figures, to appear in Optics Letter