Phase matching of degenerate four wave mixing in silicon-chalcogenide slot waveguides

We present a novel design route for silicon/chalcogenide hybrid slot waveguides, which allows waveguide geometries with FOM > 1, a maximum field concentration within the infiltrated material and a vanishing group velocity dispersion (GVD) at the same time [1]. The independent adjustment of the GVD and the mode profile is achieved by a small periodic variation of the refractive index along the waveguide. This introduces a photonic band gap for the waveguide mode leading to additional band bending in the vicinity of the band gap. With the presented scheme the phase matching condition can be fulfilled independently from the wave guide cross section. The GVD = 0 condition can be easily tuned to the wavelength of interest allowing a flexible design of the hybrid photonic components.