Beam propagation in Kerr-type nonlinear waveguides

A recent analytical study on nonlinearly induced diffraction and its influe nce on light beam propagation and spatial soliton formation in nonlinear me dia is extended here towards numerical investigations on beams' interaction in Kerr-type nonlinear waveguides. It is shown that the nonlinearly induce d diffraction, and not the nonparaxiality and effects of the longitudinal f ield component which have been usually considered as reasons for preventing the catastrophic collapse of optical beams in bulk Kerr-type nonlinear med ia, is the mechanism which controls the behaviour of the beams in the regio n of their interaction (i.e., in the highest energy density region) and lim its the beam narrowing there. Energy conservation laws are derived and disc ussed.