Comparison of Lumerical FDTD and Tidy3D for three-dimensional FDTD simulations of passive silicon photonic components

Abstract

We benchmark Lumerical FDTD and Tidy3D for 3D simulations of passive silicon photonic components on the SOI platform. Six devices -- including an MMI, directional coupler, waveguide crossing, mode converter, polarization splitter rotator, and ring resonator -- are simulated under matched conditions using geometries from the generic PDK from GDSFactory. Our study emphasize on comparing simulation accuracy across both solvers, alongside an analysis of runtime and broadband behavior over varying resolutions and bandwidths. Results show that both solvers are reliable with minimal discrepancies