Spatiotemporal discrete multicolor solitons
  We have found various families of two-dimensional spatiotemporal solitons in quadratically nonlinear waveguide arrays. The families of unstaggered odd, even and twisted stationary solutions are thoroughly characterized and their stability against perturbations is investigated. We show that the twisted and even solutions display instability, while most of the odd solitons show remarkable stability upon evolution. 
Zhiyong Xu, Yaroslav V. Kartashov, Lucian-Cornel Crasovan, Dumitru   Mihalache, and Lluis Torner