Spatial Solitons Caused by Cascaded Second-Order Nonlinearity in LiNbO3 Planar Waveguide

Self-trapped optical solitons were proposed from the early days of nonlinear optics and their demonstration based on the third-order nonlinearity have been reported in both the temporal and spatial regimes. 1-3 Recently it has been predicted that a cascaded second-order nonlinearity can produce effects similar to third-order nonlinearities with orders of magnitude higher nonlinear phase shifts. In fact, large nonlinear phase shifts have already been reported.4-5 Presented here is the first demonstration of spatial solitons due to the cascaded second-order nonlinearity.