We investigate experimentally the propagation of fundamental Gaussian beams and vortices in a two-dimensional 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 AmericaPDF Article