Modal Analysis of Optical Waveguide using a Novel Symplectic Compact FDTD Schemes

For modal analysis of longitudinally invariant optical devices, the compact-finite-difference time-domain is an efficient algorithm for alleviating the large amount of storage space and computing time under the 3D complex structure simulation. However, this algorithm needs to scale down the time step to mitigate the numerical dispersion errors while simulating optical waveguide working at high frequency. Here, a novel high-order symplectic compact FDTD scheme is proposed, which is attributed to the theory combination of the fast-spatial scheme and stable temporal scheme. The research results not only verify the effectiveness by numerical experiment on a planar dielectric waveguide with complex cross section, but also provide efficient theoretical guidance for the design and optimization of optical devices at the nanometer scale.