Manipulating the information carried by an optical beam with reflexive photorefractive beam coupling

A two-beam coupling interaction of an information-bearing beam with a copy of itself in a photorefractive medium changes the spatiotemporal nature of the beam. We analyze the reflexive coupling of an informationbearing beam carrying two or more spatiotemporal signals, using a one-dimensional model. We find that the statistical information content of the beam can be increased or decreased by use of reflexive coupling. In particular, we show that the reflexive interaction can be used to selectively enhance a given signal over others on the basis of intensity and that, for example, a pair of spatially overlapping but temporally independent signals can be made spatially orthogonal.