We have experimentally investigated the soliton interaction in a passively mode-locked fiber ring laser and revealed the existence of three types of strong soliton interaction: a global type of soliton interaction caused by the existence of unstable cw components, a local type of soliton interaction mediated through the radiative dispersive waves, and the direct soliton interaction. We found th...

A time-dependent model for the formation of self-trapped optical beams in photorefractive media by counterpropagating laser beams is analysed. It is shown that dynamically the beams may form stable steady-state structures or display periodic and irregular temporal behaviour. Steady-state solutions of non-uniform cross section are found, representing a general class of self-trapped waveguides, t...

We present exact analytical bright and dark (black and grey) solitary wave solutions of a nonlinear Schrödinger-type equation describing the propagation of spatial beams in media exhibiting a saturable nonlinearity (such as centrosymmetric photorefractive materials). A qualitative study of the stationary equation is carried out together with a discussion of the stability of the solutions.

We report the experimental demonstration of a photorefractive dynamic holographic memory that has a simple feedback architecture stabilized through a novel spatial sampling technique. By using dynamic copying to compensate for photorefractive decay, this memory provides nondestructive readout, selective erasure and rewriting, and real-time adaptation of holograms through an arbitrarily large nu...

Double gratings form in anisotropic photorefractive crystals when two plane waves intersecting inside the crystal have both extraordinary and ordinary wave components. The effect can be observed by reading out the two gratings with extraordinary or ordinary light. Experiments confirm the theoretical predictions. The relevance of these results in using photorefractive crystals for holographic st...

We predict the formation of optical spatial solitons in photorefractive polymers. The orientational enhancement from the doped chromophores and the dependency of the quantum efficiency of generating mobile holes on the electric field make the polymeric solitons behave differently from other photorefractive solitons.

The capabilities of photorefractive crystals as media for holographic interconnections in neural networks are examined. Limitations on the density of interconnections and the number of holographic associations which can be stored in photorefractive crystals are derived. Optical architectures for implementing various neural schemes are described. Experimental results are presented for one of the...

A time resolved study of the behavior of a single beam in photorefractive iron doped indium phosphide is provided down to the microsecond range, showing that infrared beam bending does occur on the micro-second time scale for moderate beam intensities. Two distinct time scales are evidenced, the behavior of which are the sign of two different photorefractive mechanisms.