Conformal dielectric overlayers for engineering dispersion and effective nonlinearity of silicon nanophotonic wires

We introduce and study numerically a method for dispersion engineering of Si nanophotonic wires using a thin conformal silicon nitride film deposited around the Si core. Simulations show that this approach may be used to achieve the dispersion characteristics required for broadband, phase-matched, four-wave mixing processes, while simultaneously maintaining strong modal confinement within the Si core for high effective nonlinearity.