Using numerical analysis we demonstrate the existence of vortex solitons at
the interface separating two different photonic lattices. We consider the
conditions for the existence of discrete vortex states at such interface and
also study their stability. A novel type of interface vortex solitons with
five lobes is observed. Also different topological charges and phase
structures of such solutions are studied, as well as influence of different
lattice intensities. Other observed solutions are in the form of discrete
solitons with six lobes. For lower beam powers such solutions are stable
during propagation, but for higher beam powers they oscillate during
propagation in a way indicating the exchange of power between neighboring
lobes, or show dynamical instabilities.
Discrete Solitons and Soliton-Induced Dislocations in Partially Coherent Photonic Lattices
