Information transfer between solitary waves in the saturable Schrodinger equation

In this paper we study the transfer of information between colliding solitary waves. By this we mean the following: The state of a solitary wave is a set of parameters, such as amplitude, width, velocity, or phase, that can change during collisions. We say information is transferred during a collision of solitary waves A and B if the state of B after the collision depends on the state of A before the collision. This is not the case in the cubic nonlinear Schrodinger, Korteweg-de Vries, and many other integrable systems. We show by numerical simulation that information can be transferred during collisions in the (nonintegrable) saturable nonlinear Schrodinger equation. A seemingly complementary feature of collisions in this and similar systems is radiation of energy. We give results that show that significant information can be transferred with radiation no greater than a few percent. We also discuss physical realization using recently described spatial solitary light waves in a saturable glass medium.