Fast Modeling of Terahertz Plasma-Wave Devices Using Unconditionally Stable FDTD Methods

Modeling of terahertz plasmonic device is a multiscale and multiphysics problem that requires fine mesh in the electron transport regions, inevitably leading to long simulation times. In this paper, we tackle this problem by employing unconditionally stable FDTD methods for these simulations. Specifically, we present alternating direction implicit (ADI) FDTD and iterative-ADI-FDTD based efficient multiphysics model that integrate hydrodynamic equations and Maxwell's equations for modeling terahertz plasmonic devices. Using the proposed methods, we demonstrate 50% time-reduction with a nominal 3% errors in the solutions. Faster times may also be achieved at higher cost to solution-accuracy, suggesting an ability to adjust time-costs and accuracy, useful for different terahertz modeling scenarios.