Fast time-domain simulation of optical waveguide structures with a multilevel dynamically adaptive mesh refinement FDTD approach

The finite-difference time-domain (FDTD) technique has been widely employed for the modeling of both linear and nonlinear optical structures. Its main advantages, however, namely, simplicity and versatility, are offered at the expense of significant computational resources needed for the simulation of realistic geometries. In this paper, a recent approach that incorporated an adaptively refined moving mesh into the FDTD technique for microwave circuit design is applied to two-dimensional optical waveguide problems, resulting in dramatic simulation time savings, compared with FDTD, while maintaining its accuracy. To complement the applicability of the proposed technique as a novel photonics design tool, numerical error studies that facilitate the educated a priori choice of the simulation parameters are provided