Beam propagation in Kerr-type nonlinear waveguides

A recent analytical study on nonlinearly induced diffraction and its influence on light beam propagation and spatial soliton formation in nonlinear media is extended here towards numerical investigations on beams' interaction in Kerr-type nonlinear waveguides. It is shown that the nonlinearly induced diffraction, and not the nonparaxiality and effects of the longitudinal field component which have been usually considered as reasons for preventing the catastrophic collapse of optical beams in bulk Kerr-type nonlinear media, is the mechanism which controls the behaviour of the beams in the region of their interaction (i.e., in the highest energy density region) and limits the beam narrowing there. Energy conservation laws are derived and discussed.