Methodology for the optimization of nonlinear properties of waveguides: application to chalcogenide channel waveguides

Nonlinear optical devices based on third-order nonlinear effects are optimi zed when the optically induced phase shift is maximum. This phase shift can be expressed in terms of two quantities that depend on waveguide geometry and composition: the effective area and the effective nonlinear index. The coupling coefficient into the waveguide must also be considered when optima l device efficiency is sought. A combination of these three factors yields a quantity to optimize without loss of physical insight into the problem. T his method of analysis is applied to a ridge waveguide made of chalcogenide glass, which exhibits nonlinear indices as much as 400 times higher than t hat of silica glass. (C) 2000 Optical Society of America [S0740-3224(00)015 04-6] OCIS codes: 160.2750, 160.4330, 230.7380.