Cascaded second-order nonlinearities in waveguides

The cascaded second-order nonlinearity arising from the second-harmonic generation process in noncentrosymmetric media is a novel approach to achieving the nonlinear phase shifts required for all-optical signal processing. The research presented in this dissertation demonstrated and measured the cascaded second-order nonlinearity for the first time in viable integrated optical waveguide formats.;Cascaded self-phase modulation was measured in potassium titanyl phosphate (KTiOPO;Direct interferometric measurements of the magnitude and sign of the cascaded nonlinear phase shift of the fundamental were performed in temperature-tuned lithium niobate (LiNbO;The phase shifts achieved in this research are large enough to be suitable for some all-optical signal processing functions.