Estimating relative extent of scattering loss due to sidewall roughness in slot waveguides by nw model

We apply nw model to slot waveguides with three different cladding and filling materials and calculate nw at different structural parameters to reveal the influence of these parameters on the sidewall-roughness scattering loss. Based on the power density distribution and the mode field localization, we analyze the causes of the influence rules, which are also consistent with the trends of reported experimental data in literatures. The results of the calculation and analysis in this paper have a guiding significance for the design and processing of slot waveguides.