Waveguides and waveguide arrays formed by incoherent light in photorefractive materials

Abstract We report on experimental observations of nonlinear optical waveguides and waveguide arrays formed by incoherent light in photorefractive materials. Such waveguides are made possible by creating partially spatially incoherent solitons in a noninstantaneous self-focusing photorefractive medium. In addition to planar, Y-junction, and circular waveguides, we report the first demonstration of pixel-like spatial solitons from partially incoherent light. An array of as many as 56×56 soliton pixels is readily realized by launching a spatially modulated incoherent beam into the self-focusing photorefractive medium. These solitons are stable and robust, forming a steady-state two-dimensional waveguide array in which optical coupling and control of local waveguide channels can be achieved. These experiments bring about the possibility of controlling high-power laser beams with low-power incoherent light sources as well as the possibility for optically inducing three-dimensional reconfigurable photonic lattices in a bulk medium.