We report on the phenomenon of trapping and switching of one-dimensional spatial solitons in Kerr-type nonlinear media with transverse periodic modulation of the refractive index. The solitons slowly radiate upon propagation along the periodic structure and are finally trapped in one of its guiding channels. The position of the output channel can be varied by small changes in the launching angle.
Kartashov, Y.V., Zelenina, A., Torner, L., Vysloukh, V.A. Spatial soliton switching in quasi-continuous optical arrays. "Optics letters", Març 2004, vol. 29, núm. 7, p. 766-768.