Novel nonlinear photonic functionalities in silicon nanowires

We discuss two novel nonlinear photonic functionalities of silicon nanowire waveguides. First, we address the Raman gain non-reciprocity that results from the tight light confinement in these waveguide structures, and investigate what consequences this non-reciprocal effect has for Raman lasing in silicon nanowire rings. Secondly, we show that when using silicon nanowire rings for four-wave mixing experiments, one can establish quasi-phase-matching for the four-wave mixing process, simply by properly choosing the radius of the nanowire ring. We also compare this novel quasi-phase-matching approach to phase matching based on dispersion engineering.