Setzpfandt, FrankPertsch, ThomasSukhorukov, Andrey2015-12-101050-2947http://hdl.handle.net/1885/56854We describe families of discrete solitons in quadratic waveguide arrays supported by competing cascaded nonlinear interactions between one fundamental and two second-harmonic modes. We characterize the existence, stability, and excitation dynamics of these solitons and show that their features may resemble those of solitons in saturable media. Our results also demonstrate that a power threshold may appear for soliton formation, leading to a suppression of beam self-focusing which explains recent experimental observations.Author/s retain copyrightKeywords: Discrete soliton; Excitation dynamics; Experimental observation; Nonlinear interactions; Power thresholds; Quadratic solitons; Second-harmonic; Self-focusing; Soliton formation; Waveguide array; Nonlinear optics; Solitons201110.1103/PhysRevA.84.0538432016-02-24