Modeling of 2D ADI-FDTD for THz Region Using a Tridiagonal Matrix Inversion Approach

This study investigates a Transverse Electric (TE) mode using the 2D Alternating Direction Implicit (ADI) FDTD method. A 200×200 grid is designed with a PML boundary so that waves in the boundary don't reflect back or scatter outside of the grid. ADI-FDTD is an unconditionally stable method that isn't restricted by CFL conditions. We present a matrix inversion approach that uses the L U decomposition method to generate the implicit electric and magnetic field equations. Around 50–60 % of computation time reduction with small errors was observed with a 3THz electric wave. This time efficiency is dependent on the courant number (CN) and the effect of changing CN is discussed in this paper.