title: Observation of discrete quadratic surface solitons.
abstract: We report the first observation of discrete quadratic surface solitons in self-focusing and defocusing periodically poled lithium niobate waveguide arrays. By operating on either side of the phase-matching condition and using the cascading nonlinearity, both in-phase and staggered discrete surface solitons were observed. This represents the first experimental demonstration of staggered/gap surface solitons at the interface of a semi-infinite nonlinear lattice. The experimental results were found to be in good agreement with theory.
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Siviloglou
authors.forename: Konstantinos G
authors.initials: KG
authors.lastname: Makris
authors.forename: Robert
authors.initials: R
authors.lastname: Iwanow
authors.forename: Roland
authors.initials: R
authors.lastname: Schiek
authors.forename: Demetrios N
authors.initials: DN
authors.lastname: Christodoulides
authors.forename: George I
authors.initials: GI
authors.lastname: Stegeman
authors.forename: Yoohong
authors.initials: Y
authors.lastname: Min
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Sohler