Discrete interband mutual focusing in nonlinear photonic lattices

Abstract

We study nonlinear coupling of mutually incoherent beams associated with different Floquet-Bloch waves in a one-dimensional optically-induced photonic lattice. We demonstrate experimentally how such interactions lead to asymmetric mutual focusing and, for waves with opposite diffraction properties, to simultaneous focusing and defocusing as well as discreteness-induced beam localization and reshaping effects.Comment: 8 pages, 6 figures. To download the associated .avi movie, go to http://www.rsphysse.anu.edu.au/~crr124/mut_focus