Experiments on Gaussian beams and vortices in optically induced photonic lattices

We investigate experimentally the propagation of fundamental Gaussian beams and vortices in a twodimensional photonic lattice optically induced with partially coherent light. We focus on soliton–lattice interactions and vortex–lattice interactions when the lattice is operated in a nonlinear regime. In this case a host of novel phenomena is demonstrated including soliton-induced lattice dislocation–deformation, soliton hopping and slow-down, and creation of structures akin to optical polarons. In addition, we observe that the nonlinear interaction between a vortex beam and a solitonic lattice leads to lattice twisting due to a transfer of the angular momentum carried by the vortex beam to the lattice. Results demonstrating a clear transition from discrete diffraction to the formation of two-dimensional, discrete fundamental and vortex solitons in a linear lattice are also included. © 2005 Optical Society of America OCIS codes: 190.5940, 270.5530, 190.4420.