title: Semidiscrete composite solitons in arrays of quadratically nonlinear waveguides.
abstract: We demonstrate that an array of discrete waveguides on a slab substrate, both featuring chi2 nonlinearity, supports stable solitons composed of discrete and continuous components. Two classes of fundamental composite soliton are identified: ones consisting of a discrete fundamental-frequency (FF) component in the waveguide array, coupled to a continuous second-harmonic (SH) component in the slab waveguide, and solitons with an inverted FF/SH structure. Twisted bound states of the fundamental solitons are found, too. In contrast with the usual systems, the intersite-centered fundamental solitons and bound states with the twisted continuous components are stable over almost the entire domain of their existence.
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA. panoiu@cumsl.msl.columbia.edu
authors.forename: Nicolae C
authors.initials: NC
authors.lastname: Panoiu
authors.forename: Richard M
authors.initials: RM
authors.lastname: Osgood
authors.forename: Boris A
authors.initials: BA
authors.lastname: Malomed