title: Formation and light guiding properties of dark solitons in one-dimensional waveguide arrays.
abstract: We report on the formation of dark discrete solitons in a nonlinear periodic system consisting of evanescently coupled channel waveguides in defocusing lithium niobate. Localized nonlinear dark modes displaying a phase jump in the center that is located either on-channel (mode A) or in-between channels (mode B) are formed, which is to our knowledge the first experimental observation of mode B. By numerical simulations we find that the saturable nature of the nonlinearity is responsible for the improved stability of mode B. The ability of the induced refractive index structures to guide light of a low-power probe beam is demonstrated.
authors.affiliation: Institute of Physics and Physical Technology, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany.
authors.forename: Eugene
authors.initials: E
authors.lastname: Smirnov
authors.forename: Christian E
authors.initials: CE
authors.lastname: Rüter
authors.forename: Milutin
authors.initials: M
authors.lastname: Stepić
authors.forename: Detlef
authors.initials: D
authors.lastname: Kip
authors.forename: Vladimir
authors.initials: V
authors.lastname: Shandarov