Beam control in tri-core photonic lattices

We report on theoretical investigations of beam control in one-dimensional tri-core photonic lattices (PLs). Linear splitting is illustrated in tri-core PLs; the effect of defect strength on the splitting is discussed in depth for single-wavelength light. We reveal that splitting disappears when the defect strength trends to zero, while reoccurring under nonlinearity. Multi-color splitting and active control are also proposed in such photonic structures.