One-Step Leapfrog FLOD BOR-FDTD Method for Electromagnetic Wave Propagation in Drude Plasma With CPML

In this paper, we proposed and implemented a one-step leapfrog fundamental locally onedimensional body of revolution finite-difference time-domain (FLOD BOR-FDTD) method to address the problem of electromagnetic wave propagation in axisymmetric Drude plasma. The BOR-FDTD method, which specializes in solving rotationally symmetric problems, has been successfully applied to simulate electromagnetic scattering from PEC structures. In this work, we extend the BOR-FDTD method to model electromagnetic wave propagation in Drude plasma using the auxiliary differential equation (ADE) technique. To address the limitations imposed by the Courant-Friedrichs-Lewy (CFL) condition, we derive and optimize the FLOD BOR-FDTD method, which divides a time step into two sub-steps, allowing for larger time intervals and reduced memory usage. To further enhance efficiency, we introduce one-step leapfrog FLOD BOR-FDTD scheme that eliminates the need for time-step subdivision and minimizes floating-point operations. Additionally, a BOR CFS-PML absorbing boundary is integrated within this framework to effectively absorb outgoing waves and minimize boundary reflections. The accuracy and efficiency of the proposed method are validated through numerical examples of normal and oblique plane wave incidence on homogeneous and inhomogeneous Drude plasma.