| I will discuss Landau-Zener tunnelling in optical waveguide arrays that are theoretically described by a discrete nonlinear Schroedinger equation. Light injected in a specific band of the Bloch spectrum in the propagation constant can be transmitted to another band, changing its physical properties. This can be achieved using two coupled waveguide arrays with different refractive indices. The phenomenon has been observed in experiments and could also allow the realization of light filters. I will also briefly discuss the coexistence of self-trapping and Josephson oscillations in weakly coupled waveguide arrays. |
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