Numerical investigation of taper parameters for high Q infiltrated nanobeam slot microcavities

► Investigation of the combination of photonic nanobeam microcavities and slot waveguides using their field enhancing properties. ► By infiltrating the slot with e.g. polymer or chalcogenide glass nonlinear optical devices can be created. ► The Q factor of the resonator is enhanced by reducing scattering losses for taper parameters that were figured out with numerical investigations. ► Q factors of up to 100,000 were achieved for taper consisting only of two pores. Photonic nanobeam microcavities are devices for applications where strong light–matter-interaction is needed. They are characterized by a strong field enhancement in a small volume, which can be used for nonlinear optical applications. To enhance such effects, a solid microcavity can be replaced by a slot, that can be infiltrated with a material of choice (e.g. chalcogenide glasses or nonlinear polymers). Here, the parameters needed to create high quality nanobeam slot microcavities are numerically investigated. Design rules for the minimization of scattering losses and thus the enhancement of the Q factor are reviewed and discussed.