All-Optical Switching in Integrated Directional Couplers and Mach Zehnder Interferometers with Cascading

Abstract

The second-order nonlinear interaction between a fundamental light wave and its second harmonic causes energy transfer between the interacting waves (second harmonic generation (SHG)) and modifies their phases nonlinearly (cascaded nonlinearity) [1]. This implies that all-optical switching can be implemented on the basis of cascading in phase-sensitive waveguide structures [2].