Observation of diffraction-managed discrete solitons in curved waveguide arrays

We observe the formation of discrete diffraction-managed optical solitons in arrays of periodically curved coupled waveguides for two types of modulated structures: laser-written arrays in silica glass with self-focusing nonlinearity and lithium niobate waveguide arrays with self-defocusing photorefractive nonlinearity. Our results demonstrate that, for both types of nonlinear response, soliton formation occurs after transitional self-induced beam broadening, being fundamentally different from nonlinear self-focusing and defocusing in a bulk medium or discrete self-trapping in straight waveguides.