Fields of nonlinear cladding optical waveguides excited by butt-coupled linear waveguides at medium power levels

The evolution of medium power fields of nonlinear optical waveguides is investigated numerically. The analysis method is based on mode matching of local normal modes of bounded waveguides. Nonlinear cladding waveguides are butt-coupled to linear waveguides. The path of a medium power level beam winds between the film and the nonlinear cladding. The input beam travels toward the nonlinear modal field, at which point the beam is not stationary. After the beam passes the location, it is forced to turn back. The lateral shift of an incident waveguide affects the path of a beam. Saturation and linear absorption lessens the oscillation of a winding path.