We report the observation of almost perfect light tunneling inhibition at the edge and inside laser-written waveguide arrays due to band collapse. When the refractive index of the guiding channels is harmonically modulated along the propagation direction and out-of-phase in adjacent guides, light is trapped in the excited waveguide over a long distance due to resonances. The phenomenon can be used for tuning the localization threshold power.
Szameit, A., Kartashov, Y.V., Dreisow, F., Heinrich, M., Pertsch, T., Nolte, S., Tunnermann, A., Vysloukh, V.A., Lederer, F., Torner, L. Inhibition of light tunneling in waveguide arrays. "Physical review letters", Abril 2009, vol. 102, núm. 153901, p. 1-4.